Elgg Documentation (master)¶

Elgg (pronunciation) is an open source rapid development framework for socially aware web applications. It is a great fit for building any app where users log in and share information.

Features¶

Well-documented core API that allows developers to kick start their new project with a simple learning curve

Composer is the package manager of choice that greatly simplifes installation and maintenance of Elgg core and plugins

Flexible system of hooks and events that allows plugins to extend and modify most aspects of application’s functionality and behavior

Extendable system of views that allows plugins to collaborate on application’s presentation layer and built out complex custom themes

Cacheable system of static assets that allows themes and plugins to serve images, stylesheets, fonts and scripts bypassing the engine

User authentication is powered by pluggable auth modules, which allow applications to implement custom authentication protocols

Security is ensured by built-in anti CSRF validation, strict XSS filters, HMAC signatures, latest cryptographic approaches to password hashing

Client-side API powered by asynchronous JavaScript modules via RequireJS and a build-in Ajax service for easy communication with the server

Flexible entity system that allows applications to prototype new types of content and user interactions

Opinionated data model with a consolidated API layer that allows the developers to easily interface with the database

Access control system that allows applications to build granular content access policies, as well as create private networks and intranets

Groups - out of the box support for user groups

File storage powered by flexible API that allows plugins to store user-generated files and serve/stream them without booting the engine

Notifications service that allows applications to subscribe users to on-site and email notifications and implement integrations with other their-party services

RPC web services that can be used for complex integrations with external applications and mobile clients

Internationalization and localization of Elgg applications is simple and can be integrated with third-party services such as Transifex

Elgg community that can help with any arising issues and hosts a repository of 1000+ open source plugins

Under the hood:

Elgg is a modular OOP framework that is driven by DI services

NGINX or Apache compatible

Symfony2 HTTP Foundation handles requests and responses

RequireJS handles AMD

Zend Mail handles outgoing email

htmLawed XSS filters

DBAL

Phinx database migrations

CSS-Crush for CSS preprocessing

Imagine for image manipulation

Persistent caching with Memcached and/or Redis

Error handling with Monolog

Examples¶

Es wurde bereits für die Erstellung der verschiedensten Social Network-Anwendungen verwendet:

offene Social Network-Webseiten (ähnlich zu Facebook)

themenbezogene Social Network-Webseiten (wie der Elgg-Community-Seite)

private/corporate intranets

Partnervermittlungs-Webseiten

Webseiten für Bildungseinrichtungen

Firmenblogs

Im Folgenden ist die Gliederung der Dokumentation für Elgg dargestellt.

Continue Reading¶

Getting Started¶

Discover if Elgg is right for your community.

Bundled plugins¶

Elgg comes with a set of plugins. These provide the basic functionality for your social network.

Blog¶

A weblog, or blog, is arguably one of the fundamental DNA pieces of most types of social networking site. The simplest form of personal publishing, it allows for text-based notes to be published in reverse-chronological order. Commenting is also an important part of blogging, turning an individual act of publishing into a conversation.

Elgg’s blog expands this model by providing per-entry access controls and cross-blog tagging. You can control exactly who can see each individual entry, as well as find other entries that people have written on similar topics. You can also see entries written by your friends (that you have access to).

Siehe auch

Blogging on Wikipedia

Dashboard¶

A typical Elgg dashboard

The dashboard is bundled with both the full and core-only Elgg packages. This is a users portal to activity that is important to them both from within the site and from external sources. Using Elgg’s powerful widget API, it is possible to build widgets that pull out relevant content from within an Elgg powered site as well as grab information from third party sources such as Twitter or Flickr (providing those widgets exist). A users dashboard is not the same as their profile, whereas the profile is for consumption by others, the dashboard is a space for users to use for their own needs.

Diagnostics¶

For the technically savvy user, system diagnostics enables you to quickly evaluate the server environment, Elgg code, and plugins of an Elgg install. Diagnostics is a core system plugin that comes turned on by default with Elgg. To download the diagnostics file, follow the steps below. The file is a dump of all sorts of useful information.

To use:

Log in as Administrator
Go to Administration -> Administer -> Utilities ->System Diagnostics
Click ‚Download‘

System diagnostics dump file contents:

List of all Elgg files along with a hash for each file
List of all the plugins
PHP superglobals
PHP settings
Apache settings
Elgg CONFIG values
- language strings
- site settings
- database settings
- plugin hooks
- actions
- views
- page handlers
- much more

File repository¶

A file in an Elgg file repository

The file repository allows users to upload any kind of file. As with everything in an Elgg system, you can filter uploaded files by tag and restrict access so that they’re only visible by the people you want them to be. Each file may also have comments attached to it.

There are a number of different uses for this functionality

Photo gallery¶

When a user uploads photographs or other pictures, they are automatically collated into an Elgg photo gallery that can be browsed through. Users can also see pictures that their friends have uploaded, or see pictures attached to a group. Clicking into an individual file shows a larger version of the photo.

Podcasting¶

An Elgg file repository RSS feed automatically doubles as an RSS feed, so you can subscribe to new audio content using programs like iTunes.

Special content¶

It is possible for other plugins to add to the players available for different content types. It’s possible for a plugin author to embed a viewer for Word documents, for example.

Note for developers¶

To add a special content type player, create a plugin with views of the form file/specialcontent/mime/type. For example, to create a special viewer for Word documents, you would create a view called file/specialcontent/application/msword, because application/msword is the MIME-type for Word documents. Within this view, the ElggEntity version of the file will be referenced as $vars['entity']. Therefore, the URL of the downloadable file is:

echo $vars['entity']->getDownloadURL();

Using this, it should be possible to develop most types of embeddable viewers.

Friends¶

Being a social network framework Elgg supports relationships between users.

By default any user can befriend any other user, it’s like following the activity of the other user.

After enabling friendship requests as a feature of the Friends plugin, when user A wants to be friends with user B, user B has to approve the request. Upon approval user A will be friends with user B and user B will be friends with user A.

Groups¶

A typical group profile

Once you have found others with similar interests - or perhaps you are part of a research groups or a course/class - you may want to have a more structured setting to share content and discuss ideas. This is where Elgg’s powerful group building can be used. You can create and moderate as many groups as you like

You can keep all group activity private to the group or you can use the ‚make public‘ option to disseminate work to the wider public.
Each group produces granular RSS feeds, so it is easy to follow group developments
Each group has its own URL and profile
Each group comes with a File repository, forum, pages and messageboard

Messageboard¶

A sample messageboard placed on the profile

The messageboard - similar to ‚The Wall‘ in Facebook or a comment wall in other networks is a plugin that lets users put a messageboard widget on their profile. Other users can then post messages that will appear on the messageboard. You can then reply directly to any message and view the history between yourself and the person posting the message.

Messages¶

Message notification

Private messaging can be sent to users by clicking on their avatar or profile link, providing you have permission. Then, using the built in WYSIWYG editor, it is possible to format the message. Each user has their own inbox and sentbox. It is possible to be notified via email of new messages.

When users first login, they will be notified about any new message by the messages notification mechanism in their top toolbar.

Pages¶

An Elgg Page

The pages plugin allows you to save and store hierarchically-organized pages of text, and restrict both reading and writing privileges to them. This means that you can collaboratively create a set of documents with a loose collection of people, participate in a writing process with a formal group, or simply use the functionality to write a document that only you can see, and only choose to share it once it’s done. The easy navigation menu allows you to see the whole document structure from any page. You can create as many of these structures as you like; each individual page has its own access controls, so you can reveal portions of the structure while keeping others hidden. In keeping with all other elements in Elgg, you can add comments on a page, or search for pages by tag.

Usage¶

Pages really come into their own in two areas, firstly as a way for users to build up things such as a resume, reflective documentation and so on. The second thing is in the area of collaboration, especially when in the context of groups. With the powerful access controls on both read and write, this plugin is ideal for collaborative document creation.

Bemerkung

Developers should note that there are actually 2 types of pages:

Top-level pages (with subtype page_top)
Normal pages (with subtype page)

Profile¶

An Elgg profile

The profile plugin is bundled with both the full and core-only Elgg packages. The intention is that it can be disabled and replaced with another profile plugin if you wish. It provides a number of pieces of functionality which many consider fundamental to the concept of a social networking site, and is unique within the plugins because the profile icon it defines is referenced as standard from all over the system.

User details¶

This provides information about a user, which is configurable from within the plugin’s start.php file. You can change the available profile fields form the admin panel. Each profile field has its own access restriction, so users can choose exactly who can see each individual element. Some of the fields contain tags (for example skills) limiting access to a field will also limit who can find you by that tag.

User avatar¶

The Elgg context menu

The user avatar represents a user (or a group) throughout the site. By default, this includes a context-sensitive menu that allows you to perform actions on the user it belongs to wherever you see their avatar. For example, you can add them as a friend, send an internal message, and more. Each plugin can add to this context menu, so its full contents will vary depending on the functionality active in the current Elgg site.

Notes for developers¶

Using a different profile icon

To replace the profile icon, or provide more content, extend the icon/user/default view.

Adding to the context menu

The context menu can be expanded by registering a plugin hook for ‚register‘ ‚menu:user_hover‘, the following sections have special meaning:

default for non-active links (eg to read a blog)
admin for links accessible by administrators only

In each case, the user in question will be passed as $params['entity'].

The Wire¶

Elgg wire plugin „The Wire“ is Twitter-style microblogging plugin that allows users to post notes to the wire.

User validation by e-mail¶

The uservalidationbyemail plugin adds a step to the user registration process. After the user registered on the site, an e-mail is sent to their e-mail address in order to validate that the e-mail address belongs to the user. In the e-mail is an verification link, only after the user clicked on the link will the account of the user be able to login to the site.

The process for the user¶

The user creates an account by going to the registration page of your site
After the account is created the user lands on a page with instructions to check their e-mail account for the validation e-mail
In the validation e-mail is a link to confirm their e-mail address
After clicking on the link, the account is validated
If possible the user gets logged in

If the user tries to login before validating their account an error is shown to indicate that the user needs to check their e-mail account. Also the validation e-mail is sent again.

Options for site administrators¶

A site administrator can take some actions on unvalidated accounts. Under Administration -> Users -> Unvalidated is a list of unvalidated users. The administrator can manualy validate or delete the user. Also the option to resend the validation e-mail is present.

The following plugins are also bundled with Elgg, but are not (yet) documented

activity
bookmarks
ckeditor
custom_index
developers
discussions
embed
externalpages
friends_collections
garbagecollector
invitefriends
likes
members
notifications
reportedcontent
search
site_notifications
system_log
tagcloud
web_services

License¶

MIT or GPLv2¶

A full Elgg package that includes the framework and a core set of plugins is available under version 2 of the GNU General Public License (GPLv2). We also make the framework (without the plugins) available under the MIT license.

FAQ¶

The following answers are provided as a convenience to you; they are not legal counsel. Consult with a lawyer to be sure about the answers to these questions. The Elgg Foundation cannot be held responsible for decisions you make based on what you read on this page.

For questions not answered here, please refer to the official FAQ for the GPLv2.

How much does Elgg cost?¶

Elgg is free to download, install, and use. If you’d like to donate, we do appreciate our financial supporters!

Can I remove the Elgg branding/links?¶

Yes.

Can I modify the source code?¶

Yes, but in general we recommend you make your modifications as plugins so that when a new version of Elgg is released, the upgrade process is as painless as possible.

Can I charge my users membership fees?¶

Yes.

If I modify Elgg, do I have to make the changes available?¶

No, if you are using Elgg to provide a service, you do not have to make the source available. If you distribute a modified version of Elgg, then you must include the source code for the changes.

If I use Elgg to host a network, does The Elgg Foundation have any rights over my network?¶

No.

What’s the difference between the MIT and GPL versions?¶

Plugins are not included with the MIT version.

You can distribute a commercial product based on Elgg using the MIT version without making your modifications available.

With the GPL licensed version, you have to include make your modifications of the framework public if you redistribute the framework.

Why are plugins missing from the MIT version?¶

The plugins were developed under the GPL license, so they cannot be released under an MIT license. Also, some plugins include external dependencies that are not compatible with the MIT license.

May I distribute a plugin for Elgg under a commercial license?¶

We believe you can, since plugins typically depend only the core framework and the framework is available under the MIT license. That said, we really recommend you consult with a lawyer on this particular issue to be absolutely sure.

Note that plugins released via the community site repository must be licensed under a GPLv2-compatible license. They do not necessarily have to be GPLv2, just compatible (like MIT).

Can we build our own tool that uses Elgg and sell that tool to our clients?¶

Yes, but then your clients will be free to redistribute that tool under the terms of the GPLv2.

Installation¶

Get your own instance of Elgg running in no time.

Contents

Requirements
Overview
Other Configurations
Troubleshooting

Requirements ¶

MySQL 5.5.3+ (5.0.0+ if upgrading an existing installation)
PHP 7.1+ with the following extensions:
- GD (for graphics processing)
- PDO (for database connection)
- JSON (for AJAX responses, etc.)
- XML (for reading plugin manifest files, etc.)
- Multibyte String support (for i18n)
- Proper configuration and ability to send email through an MTA
Web server with support for URL rewriting

Official support is provided for the following configurations:

Apache server
- Apache with the rewrite module enabled
- PHP running as an Apache module
Nginx server
- Nginx with PHP-FPM using FastCGI

By „official support“, we mean that:

Most development and testing is performed with these configurations
Much of the installation documentation is written assuming Apache or Nginx is used
Priority on bug reports is given to Apache and Nginx users if the bug is web server specific (but those are rare).

Browser support policy¶

Feature branches support the latest 2 versions of all major browsers as were available at the time of the first stable release on that branch.

Bugfix release will not alter browser support, even if a new version of the browser has since been released.

Major browsers here means all of the following, plus their mobile counterparts:

Android Browser

Chrome

Firefox

IE

Safari

„Support“ may mean that we take advantage of newer, unimplemented technologies but provide a JavaScript polyfill for the browsers that need it.

You may find that Elgg happens to work on unsupported browsers, but compatibility may break at any time, even during a bugfix release.

Overview ¶

Upload Elgg¶

With Composer (recommended if comfortable with CLI):

composer self-update
composer create-project elgg/starter-project:dev-master ./path/to/project/root
cd ./path/to/project/root
composer install
composer install # 2nd call is currently required
vendor/bin/elgg-cli install # follow the questions to provide installation details

From pre-packaged zip (recommended if not comfortable with CLI):

Download the latest version of Elgg
Upload the ZIP file with an FTP client to your server
Unzip the files in your domain’s document root.

Create a data folder¶

Elgg needs a special folder to store uploaded files including profile icons and photos. You will need to create this directory.

Achtung

For security reasons, this folder MUST be stored outside of your document root. If you created it under /www/ or /public_html/, you’re doing it wrong.

Once this folder has been created, you’ll need to make sure the web server Elgg is running on has permission to write to and create directories in it. This shouldn’t be a problem on Windows-based servers, but if your server runs Linux, Mac OS X or a UNIX variant, you’ll need to set the permissions on the directory.

If you are using a graphical FTP client to upload files, you can usually set permissions by right clicking on the folder and selecting ‚properties‘ or ‚Get Info‘.

Bemerkung

Directories must be executable to be read and written to. The suggested permissions depend upon the exact server and user configuration. If the data directory is owned by the web server user, the recommended permissions are 750.

Warnung

Setting your data directory to 777 will work, but it is insecure and is not recommended. If you are unsure how to correctly set permissions, contact your host for more information.

Create a MySQL database¶

Using your database administration tool of choice (if you’re unsure about this, ask your system administrator), create a new MySQL database for Elgg. You can create a MySQL database with any of the following tools:

Make sure you add a user to the database with all privileges and record the database name, username and password. You will need this information when installing Elgg.

Set up Cron¶

Elgg uses timed requests to your site to perform background tasks like sending notifications or performing database cleanup jobs. You need to configure the cron to be able to use those kind of features.

Visit your Elgg site¶

Once you’ve performed these steps, visit your Elgg site in your web browser. Elgg will take you through the rest of the installation process from there. The first account that you create at the end of the installation process will be an administrator account.

A note on settings.php and .htaccess¶

The Elgg installer will try to create two files for you:

elgg-config/settings.php, which contains local environment configuration for your installation
.htaccess, which allows Elgg to generate dynamic URLs

If these files can’t be automatically generated, for example because the web server doesn’t have write permissions in the directories, Elgg will tell you how to create them. You could also temporarily change the permissions on the root directory and the engine directory. Set the permissions on those two directories so that the web server can write those two files, complete the install process, and them change the permissions back to their original settings. If, for some reason, this won’t work, you will need to:

In elgg-config/, copy settings.example.php to settings.php, open it up in a text editor and fill in your database details
On Apache server, copy install/config/htaccess.dist to .htaccess
On Nginx server copy install/config/nginx.dist to /etc/nginx/sites-enabled and adjust it’s contents

Other Configurations ¶

Cloud9

Homestead

EasyPHP

IIS

MAMP

MariaDB

Nginx

Ubuntu

Virtual hosts

XAMPP

Troubleshooting ¶

Help! I’m having trouble installing Elgg¶

First:

Recheck that your server meets the technical requirements for Elgg.
Follow the environment-specific instructions if need be
Have you verified that mod_rewrite is being loaded?
Is the mysql apache being loaded?

Keep notes on steps that you take to fix the install. Sometimes changing some setting or file to try to fix a problem may cause some other problem later on. If you need to start over, just delete all the files, drop your database, and begin again.

I can’t save my settings on installation (I get a 404 error when saving settings)¶

Elgg relies on the mod_rewrite Apache extension in order to simulate certain URLs. For example, whenever you perform an action in Elgg, or when you visit a user’s profile, the URL is translated by the server into something Elgg understands internally. This is done using rules defined in an .htaccess file, which is Apache’s standard way of defining extra configuration for a site.

This error suggests that the mod_rewrite rules aren’t being picked up correctly. This may be for several reasons. If you’re not comfortable implementing the solutions provided below, we strongly recommend that you contact your system administrator or technical support and forward this page to them.

The .htaccess, if not generated automatically (that happens when you have problem with mod_rewrite), you can create it by renaming install/config/htaccess.dist file you find with elgg package to .htaccess. Also if you find a .htaccess file inside the installation path, but you are still getting 404 error, make sure the contents of .htaccess are same as that of install/config/htaccess.dist.

``mod_rewrite`` isn’t installed.

Check your httpd.conf to make sure that this module is being loaded by Apache. You may have to restart Apache to get it to pick up any changes in configuration. You can also use PHP info to check to see if the module is being loaded.

The rules in ``.htaccess`` aren’t being obeyed.

In your virtual host configuration settings (which may be contained within httpd.conf), change the AllowOverride setting so that it reads:

AllowOverride all

This will tell Apache to pick up the mod_rewrite rules from .htaccess.

Elgg is not installed in the root of your web directory (ex: http://example.org/elgg/ instead of http://example.org/)

The install script redirects me to „action“ when it should be „actions“¶

This is a problem with your mod_rewrite setup.

Achtung

DO NOT, REPEAT, DO NOT change any directory names!

I installed in a subdirectory and my install action isn’t working!¶

If you installed Elgg so that it is reached with an address like http://example.org/mysite/ rather than http://example.org/, there is a small chance that the rewrite rules in .htaccess will not be processed correctly. This is usually due to using an alias with Apache. You may need to give mod_rewrite a pointer to where your Elgg installation is.

Open up .htaccess in a text editor
Where prompted, add a line like RewriteBase /path/to/your/elgg/installation/ (Don’t forget the trailing slash)
Save the file and refresh your browser.

Please note that the path you are using is the web path, minus the host.

For example, if you reach your elgg install at http://example.org/elgg/, you would set the base like this:

RewriteBase /elgg/

Please note that installing in a subdirectory does not require using RewriteBase. There are only some rare circumstances when it is needed due to the set up of the server.

I did everything! mod_rewrite is working fine, but still the 404 error¶

Maybe there is a problem with the file .htaccess. Sometimes the elgg install routine is unable to create one and unable to tell you that. If you are on this point and tried everything that is written above:

check if it is really the elgg-created .htaccess (not only a dummy provided from the server provider)
if it is not the elgg provided htaccess file, use the htaccess_dist (rename it to .htaccess)

I get an error message that the rewrite test failed after the requirements check page¶

I get the following messages after the requirements check step (step 2) of the install:

We think your server is running the Apache web server.

The rewrite test failed and the most likely cause is that AllowOverride is not set to All for Elgg’s directory. This prevents Apache from processing the .htaccess file which contains the rewrite rules.

A less likely cause is Apache is configured with an alias for your Elgg directory and you need to set the RewriteBase in your .htaccess. There are further instructions in the .htaccess file in your Elgg directory.

After this error, everinteraction with the web interface results in a error 500 (Internal Server Error)

This is likely caused by not loading the „filter module by un-commenting the

#LoadModule filter_module modules/mod_filter.so

line in the „httpd.conf“ file.

the Apache „error.log“ file will contain an entry similar to:

… .htaccess: Invalid command ‚AddOutputFilterByType‘, perhaps misspelled or defined by a module not included in the server configuration

There is a white page after I submit my database settings¶

Check that the Apache mysql module is installed and is being loaded.

I’m getting a 404 error with a really long url¶

If you see a 404 error during the install or on the creation of the first user with a url like: http://example.com/homepages/26/d147515119/htdocs/elgg/action/register that means your site url is incorrect in your sites_entity table in your database. This was set by you on the second page of the install. Elgg tries to guess the correct value but has difficulty with shared hosting sites. Use phpMyAdmin to edit this value to the correct base url.

I am having trouble setting my data path¶

This is highly server specific so it is difficult to give specific advice. If you have created a directory for uploading data, make sure your http server can access it. The easiest (but least secure) way to do this is give it permissions 777. It is better to give the web server ownership of the directory and limit the permissions.

Warnung

Setting directory permissions to 777 allows the ENTIRE internet to place files in your directory structure an possibly infect you webserver with malware. Setting permissions to 750 should be more than enough.

The top cause of this issue is PHP configured to prevent access to most directories using open_basedir. You may want to check with your hosting provider on this.

Make sure the path is correct and ends with a /. You can check the path in your database in the config table.

If you only have ftp access to your server and created a directory but do not know the path of it, you might be able to figure it out from the www file path set in your config database table. Asking for help from your hosting help team is recommended at this stage.

I can’t validate my admin account because I don’t have an email server!¶

While it’s true that normal accounts (aside from those created from the admin panel) require their email address to be authenticated before they can log in, the admin account does not.

Once you have registered your first account you will be able to log in using the credentials you have provided!

I have tried all of these suggestions and I still cannot install Elgg¶

It is possible that during the process of debugging your install you have broken something else. Try doing a clean install:

drop your elgg database
delete your data directory
delete the Elgg source files
start over

If that fails, seek the help of the Elgg community. Be sure to mention what version of Elgg you are installing, details of your server platform, and any error messages that you may have received including ones in the error log of your server.

Developer Overview¶

This is a quick developer introduction to Elgg. It covers the basic approach to working with Elgg as a framework, and mentions some of the terms and technologies used.

See the Developer Guides for tutorials or the Design Docs for in-depth discussion on design.

Database and Persistence¶

Elgg uses MySQL 5.5 or higher for data persistence, and maps database values into Entities (a representation of an atomic unit of information) and Extenders (additional information and descriptions about Entities). Elgg supports additional information such as relationships between Entities, activity streams, and various types of settings.

Plugins¶

Plugins change the behavior or appearance of Elgg by overriding views, or by handling events and plugin hooks. All changes to an Elgg site should be implemented through plugins to ensure upgrading core is easy.

Actions¶

Actions are the primary way users interact with an Elgg site. Actions are registered by plugins.

Events and Plugin Hooks¶

Events and Plugin Hooks are used in Elgg Plugins to interact with the Elgg engine under certain circumstances. Events and hooks are triggered at strategic times throughout Elgg’s boot and execution process, and allows plugins to modify or cancel the default behavior.

Views¶

Views are the primary presentation layer for Elgg. Views can be overridden or extended by Plugins. Views are categories into a Viewtype, which hints at what sort of output should be expected by the view.

JavaScript¶

Elgg uses an AMD-compatible JavaScript system provided by RequireJs. Bundled with Elgg are jQuery, jQuery UI, jQuery Form, and jQuery UI Autocomplete.

Plugins can load their own JS libs.

Internationalization¶

Elgg’s interface supports multiple languages, and uses Transifex for translation.

Caching¶

Elgg uses two caches to improve performance: a system cache and SimpleCache.

3rd party libraries¶

The use of 3rd party libraries in Elgg is managed by using Composer dependencies. Examples of 3rd party libraries are jQuery, RequireJs or Zend mail.

To get a list of all the Elgg dependencies check out the Packagist page for Elgg.

Database Seeding¶

Elgg provides some base database seeds to populate the database with entities for testing purposes.

You can run the following commands to seed and unseed the database.

# seed the database
vendor/bin/elgg-cli database:seed

# unseed the database
vendor/bin/elgg-cli database:unseed

Plugins can register their own seeds via 'seeds', 'database' hook. The handler must return the class name of the seed, which must extend \Elgg\Database\Seeder\Seed class.

Elgg CLI¶

Contents

elgg-cli command line tools
Available commands
Adding custom commands

elgg-cli command line tools ¶

Depending on how you installed Elgg and your server configuration you can access``elgg-cli`` binaries as one of the following from the root of your Elgg installation:

php ./elgg-cli list
./elgg-cli list
php ./vendor/bin/elgg-cli list
./vendor/bin/elgg-cli list

Available commands ¶

cd /path/to/elgg/

# Get help
vendor/bin/elgg-cli --help

# List all commands
vendor/bin/elgg-cli list

# Install Elgg
vendor/bin/elgg-cli install [-c|--config CONFIG]

# Seed the database with fake entities
vendor/bin/elgg-cli database:seed [-l|--limit LIMIT]

# Remove seeded faked entities
vendor/bin/elgg-cli database:unseed

# Optimize database tables
# Request garbagecollector plugin
vendor/bin/elgg-cli database:optimize

# Run cron jobs
vendor/bin/elgg-cli cron [-i|--interval INTERVAL] [-q|--quiet]

# Flush caches
vendor/bin/elgg-cli flush

# System upgrade
# -v|-vv|-vvv control verbosity of the command (helpful for debugging upgrade scripts)
vendor/bin/elgg-cli upgrade [-v]

# Upgrade and execute all async upgrades
vendor/bin/elgg-cli upgrade async [-v]

# List all, active or inactive plugins
# STATUS = all | active | inactive
vendor/bin/elgg-cli plugins:list [-s|--status STATUS]

# Activate plugins
# List plugin ids separating them with spaces: vendor/bin/elgg-cli plugins:activate activity blog
# use -f flag to resolve conflicts and dependencies
vendor/bin/elgg-cli plugins:activate [<plugins>] [-f|--force]

# Deactivate plugins
# List plugin ids separating them with spaces: vendor/bin/elgg-cli plugins:deactivate activity blog
# use -f flag to also disable dependents
vendor/bin/elgg-cli plugins:deactivate [<plugins>] [-f|--force]

Adding custom commands ¶

Plugins can add their commands to the CLI application, by adding command class name via 'commands','cli' hook. Command class must extend \Elgg\CLI\Command.

class MyCommand extends \Elgg\Сli\Command {

}

elgg_register_plugin_hook_handler('commands', 'cli', function($hook, $type, $return) {

    $return[] = MyCommand::class;

    return $return;

});

Custom commands are based on Symfony Console Commands. Please refer to their documentation for more details.

Administrator Guides¶

Best practices for effectively managing an Elgg-based site.

Getting Started¶

You have installed Elgg and worked through any potential initial issues. What now? Here are some suggestions on how to to familiarize yourself with Elgg.

Focus first on core functionality¶

When you’re new to Elgg, it’s best to explore the stock features in core and its bundled plugins before installing any third party plugins. It’s tempting install every interesting plugin from the community site, but exploring the core features builds a familiarity with Elgg’s expected behavior, and prevents introducing any confusing bugs from third party plugin into your new Elgg network.

Elgg installs with a basic set of social network plugins activated: blogs, social bookmarking, files, groups, likes, message boards, wiki-like pages, user profiles, and microblogging. To change the plugins that are activated, log in as an admin user, then use the topbar to browse to Administration, then to Plugins on the right sidebar.

Bemerkung

The user you create during installation is an admin user.

Create test users¶

Users can be created two ways in stock Elgg:

Complete the signup process using a different email address and username. (Logout first or use a different browser!)

Add a user through the Admin section by browsing to Administration -> Users -> Add New User.

Bemerkung

Users that self-register must validate their account through email before they can log in. Users that an admin creates are already validated.

Explore user functionality¶

Use your test users to create blogs, add widgets to your profile or dashboard, post to the Wire (microblogging), and create pages (wiki-like page creation). Investigate the Settings on the topbar. This is where a user sets notification settings and configures tools (which will be blank because none of the default plugins add controls here).

Explore admin functionality¶

All of the admin controls are found by clicking Administration in the topbar. The has a dashboard with a widget that explains the various sections. Change options in the Configure menu to change how Elgg looks and acts.

Extending Elgg¶

After exploring what Elgg can do out of the box, install some themes and plugins. You can find many plugins and themes at the community site that have been developed by third parties. These plugins do everything from changing language strings, to adding chat, to completely redesigning Elgg’s interface. Because these plugins are not official, be certain to check the comments to make sure you only install well-written plugins by high quality developers.

Composer installation¶

The easiest way to keep your Elgg site up-to-date is by using Composer. Composer will take care of installing all the required dependencies of all plugins and Elgg, while also keeping those depencies up-to-date without having conflicts.

Contents

Install Composer
Install Elgg as a Composer Project
Setup version controls
Install plugins
Commit
Deploy to production

Install Composer ¶

https://getcomposer.org/download/

Install Elgg as a Composer Project ¶

composer self-update
composer create-project elgg/starter-project:dev-master ./path/to/my/project
cd ./path/to/my/project
composer install

This will create a composer.json file based of the Elgg starter project which has the basics of installing Elgg.

Open your browser¶

Go to your browser and install Elgg via the installation interface

Setup version controls ¶

This step is optional but highly recommended. It’ll allow you to easily manage the installation of the same plugin versions between environments (development/testing/production).

cd ./path/to/my/project
git init
git add .
git commit -a -m 'Initial commit'
git remote add origin <git repository url>
git push -u origin master

Install plugins ¶

Install plugins as Composer depencies. This assumes that a plugin has been registered on Packagist

composer require hypejunction/hypefeed
composer require hypejunction/hypeinteractions
# whatever else you need

Commit ¶

Make sure composer.lock is not ignored in .gitignore

git add .
git commit -a -m 'Add new plugins'
git push origin master

Deploy to production ¶

Initial Deploy¶

cd ./path/to/www

# you can also use git clone
git init
git remote add origin <git repository url>
git pull origin master

composer install

Subsequent Deploys¶

cd ./path/to/www
git pull origin master

# never run composer update in production
composer install

Upgrading Elgg¶

This document will guide you through steps necessary to upgrade your Elgg installation to the latest version.

If you’ve written custom plugins, you should also read the developer guides for information on upgrading plugin code for the latest version of Elgg.

Contents

Advice
From 2.3 to 3.0
Applying a patch using Composer
Earlier versions

Advice ¶

Back up your database, data directory and code
Mind any version-specific comments below
Version below 2.0 are advised to only upgrade one minor version at a time
You can upgrade from any minor version to any higher minor version in the same major (2.0 -> 2.1 or 2.0 -> 2.3)
You can only upgrade the latest minor version in the previous major version to any minor version in the next version (2.3 -> 3.0 or 2.3 -> 3.2, but not 2.2 -> 3.x).
From Elgg 2.3.* you can upgrade to any future version of Elgg without having to go through each minor version (e.g. you can upgrade directly from 2.3.8 to 3.2.5, without having to upgrade to 3.0 and 3.1)
Try out the new version on a test site before doing an upgrade
Report any problems in plugins to the plugin authors
If you are a plugin author you can report any backwards-compatibility issues to GitHub

From 2.3 to 3.0 ¶

1. Update `composer.json`¶

If you have used Elgg’s starter project to install Elgg 2.3, you may need to update your composer.json:

change platform requirements to PHP >= 7.0

optionally, set autoloader optimization parameters

optionally, disable fxp-asset plugin in favor of asset-packagist

Your composer.json would look something like this (depending what changes you may have introduced yourself):

{
        "type": "project",
        "name": "elgg/starter-project",
        "require": {
                "elgg/elgg": "3.*"
        },
        "config": {
                "process-timeout": 0,
                "platform": {
                        "php": "7.0"
                },
                "fxp-asset": {
                        "enabled": false
                },
                "optimize-autoloader": true,
                "apcu-autoloader": true
        },
        "repositories": [
                {
                        "type": "composer",
                        "url": "https://asset-packagist.org"
          }
        ]
}

2. Update `.htaccess`¶

Find the line:

RewriteRule ^(.*)$ index.php?__elgg_uri=$1 [QSA,L]

And replace it with:

RewriteRule ^(.*)$ index.php [QSA,L]

3a. Composer Upgrade (recommended)¶

If you had your Elgg 2.3 project installed using composer, you can follow this sequence:

Back up your database, data directory, and code

composer self-update

cd ./path/to/project/root
composer require elgg/elgg:~3.0.0
composer update
vendor/bin/elgg-cli upgrade async -v

Bemerkung

In some cases the command line upgrade will fail because some database schema changes need to be applied first. In that case you need to execute the Phinx migrations manually

3b. Manual Upgrade (legacy approach)¶

Manual upgrades are a major undertaking for site admins. We discourage you from maintaining an Elgg installation using ZIP dist packages. Save yourself some time by learning how to use composer and version control systems, such as git. This task will also be complicated if you have third-party plugins and/or have made any modifications to core files!

Back up your database, data directory, and code
Log in as an admin to your site
Download the new version of Elgg from http://elgg.org
Update the files
- If upgrading to a major version, you need to overwrite all core files and remove any files that were removed from Elgg core, as they may interfere with proper functioning of your site.
- If upgrading to a minor version or patching, you need to overwrite all core files.
Merge any new changes to the rewrite rules
- For Apache from install/config/htaccess.dist into .htaccess
- For Nginx from install/config/nginx.dist into your server configuration (usually inside /etc/nginx/sites-enabled)
Visit http://your-elgg-site.com/upgrade.php
Execute asynchronous upgrades at http://your-elgg-site.com/admin/upgrades

Bemerkung

Any modifications should have been written within plugins, so that they are not lost on overwriting. If this is not the case, take care to maintain your modifications.

Bemerkung

If you are unable to access upgrade.php script and receive an error, add $CONFIG->security_protect_upgrade = false; to your settings.php and remove it after you have completed all of the upgrade steps.

Bemerkung

If you encounter issues with plugins during the upgrade, add an empty file called disabled in your /mod/ directory. This will disable the plugins, so that you can finish the core upgrade. You can then deal with issues on per-plugin basis.

If you have installed Elgg using a dist package but would now like to switch to composer:

Upgrade your current installation using Manual Upgrade method

Move your codebase to a temporary location

Create a new composer project using Elgg’s starter project following installation instructions in the root directory of your current installation

Copy third-party plugins from your old installation into /mod directory

Run Elgg’s installer using your browser or elgg-cli tool

When you reach the database step, provide the same credentials you have used for manual installation, Elgg will understand that is’s an existing installation and will not override any database values

Optionally commit your new project to version control

Applying a patch using Composer ¶

The definition of a patch can be found in the Release policy.

Your composer.json requirement for Elgg should be ~3.y.0 (where y is the minor version 0, 1, etc. you wish to have installed). This will make sure you can easily install patches without the risk of installing the next minor release.

{
        "require": {
                "elgg/elgg": "~3.0.0"
        }
}

Just to be sure you can first verify what will be installed / upgraded by executing the folowing command

# to get a full list of all packages which can be upgraded
composer update --dry-run

# or if you only wish to check for Elgg
composer update elgg/elgg --dry-run

To upgrade Elgg simply execute

# to upgrade all packages
composer update

# or to only upgrade Elgg
composer update elgg/elgg

Earlier versions ¶

Check Elgg documentation that corresponds to the Elgg version you want to upgrade to, by switching the documentation version in the lower left corner of Upgrading docs

Plugins¶

Plugins can modify the behavior of and add new features to Elgg.

Contents

Where to get plugins
The Elgg Community
- Finding Plugins
- Evaluating Plugins
Types of plugins
- Themes
- Language Packs
Installation
Plugin order

Where to get plugins ¶

Plugins can be obtained from:

The Elgg Community

Github

Third-party sites (typically for a price)

If no existing plugins meet your needs, you can hire a developer or create your own.

The Elgg Community ¶

Finding Plugins ¶

Sort based on most popular¶

On the community plugin page, you can sort by date uploaded (Filter: Newest) or number of downloads (Filter: Most downloads). Sorting by the number of downloads is a good idea if you are new to Elgg and want to see which plugins are frequently used by other administrators. These will often (but not always) be higher quality plugins that provide significant capabilities.

Use the plugin tag search¶

Next to the filtering control on the plugin page is a search box. It enables you to search by tags. Plugins authors choose the tags.

Look for particular plugin authors¶

The quality of plugins varies substantially. If you find a plugin that works well on your site, you can check what else that plugin author has developed by clicking on their name when viewing a plugin.

Evaluating Plugins ¶

Look at the comments and ratings¶

Before downloading and using a plugin, it is always a good idea to read through the comments that others have left. If you see people complaining that the plugin does not work or makes their site unstable, you probably want to stay away from that plugin. The caveat to that is that sometimes users ignore installation instructions or incorrectly install a plugin and then leave negative feedback. Further, some plugin authors have chosen to not allow comments.

Install on a test site¶

If you are trying out a plugin for the first time, it is a bad idea to install it on your production site. You should maintain a separate test site for evaluating plugins. It is a good idea to slowly roll out new plugins to your production site even after they pass your evaluation on your test site. This enables you to isolate problems introduced by a new plugin.

Types of plugins ¶

Themes ¶

Themes are plugins that modify the look-and-feel of your site. They generally include stylesheets, client-side scripts and views that alter the default presentation and behavior of Elgg.

Language Packs ¶

Language packs are plugins that provide support for other languages.

Language packs can extend and include translations for language strings found in the core, core plugins and/or third-party plugins.

Some of the language packs are already included in the core, and can be found in languages directory off Elgg’s root directory. Individual plugins tend to include their translations under the languages directory within the plugin’s root.

This structure makes it easy to create new language packs that supercede existing language strings or add support for new languages.

Installation ¶

All plugins reside in the mod directory of your Elgg installation.

To install a new plugin:

extract (unzip) contents of the plugin distribution package
copy/FTP the extracted folder into the mod directory of your Elgg installation, making sure that manifest.xml is directly under the plugin directory (e.g. if you were to install a plugin called my_elgg_plugin, plugin’s manifest would need to be found at mod/my_elgg_plugin/manifest.xml)
activate the plugin from your admin panel

To activate a plugin:

Log in to your Elgg site with your administrator account
Go to Administration -> Configure -> Plugins
Find your plugin in the list of installed plugins and click on the ‚enable‘ button.

Plugin order ¶

Plugins are loaded according to the order they are listed on the Plugins page. The initial ordering after an install is more or less random. As more plugins are added by an administrator, they are placed at the bottom of the list.

Some general rules for ordering plugins:

A theme plugin should be last or at least near the bottom
A plugin that modifies the behavior of another plugin should be lower in the plugin list

Performance¶

Make your site run as smoothly and responsively as possible.

Contents

Can Elgg scale to X million users?
Measure first
Tune MySQL
Enable caching
Hosting
- Memory, CPU and bandwidth
- Configuration
Check for poorly-behaved plugins
Use client-rendered HTML

Can Elgg scale to X million users?¶

People often ask whether Elgg can scale to large installations.

First, we might stop and ask, „where are you planning to get all those users?“ Seriously, though, this is a really interesting problem. Making Elgg scale is, if anything, an issue of technical engineering. It’s interesting but more or less a solved problem. Computer science doesn’t work differently for Elgg than for Google, for example. Getting millions of users? That’s like the Holy Grail of the entire tech industry.

Second, as with most things in life, the answer is „it depends“:

How active are your users?

What hardware is Elgg running on?

Are your plugins behaving well?

Improving the efficiency of the Elgg engine is an ongoing project, although there are limits to the amount that any script can do.

If you are serious about scalability you will probably want to look at a number of things yourself.

Measure first ¶

There is no point in throwing resources at a problem if you don’t know:

what the problem is

what resources the problem needs

where those resources are needed

Invest in some kind of profiling to tell you where your bottleneck is, especially if you’re considering throwing significant money at a problem.

Tune MySQL ¶

Elgg makes extensive use of the back end database, making many trips on each pageload. This is perfectly normal and a well configured database server will be able to cope with thousands of requests per second.

Here are some configuration tips that might help:

Make sure that MySQL is configured to use an appropriate my.cnf for the size of your website.

Increase the amount of memory available to PHP and MySQL (you will have to increase the amount of memory available to the php process in any case)

Enable caching ¶

Generally, if a program is slow, that is because it is repeatedly performing an expensive computation or operation. Caching allows the system to avoid doing that work over and over again by using memory to store the results so that you can skip all the work on subsequent requests. Below we discuss several generally-available caching solutions relevant to Elgg.

Simplecache ¶

By default, views are cached in the Elgg data directory for a given period of time. This removes the need for a view to be regenerated on every page load.

This can be disabled by setting $CONFIG->simplecache_enabled = false; For best performance, make sure this value is set to true.

This does lead to artifacts during development if you are editing themes in your plugin as the cached version will be used in preference to the one provided by your plugin.

The simple cache can be disabled via the administration menu. It is recommended that you do this on your development platform if you are writing Elgg plugins.

This cache is automatically flushed when a plugin is enabled, disabled or reordered, or when upgrade.php is executed.

For best performance, you can also create a symlink from /cache/ in your www root dir to the assetroot directory specified in your config (by default it’s located under /path/to/dataroot/caches/views_simplecache/:

cd /path/to/wwwroot/
ln -s /path/to/dataroot/caches/views_simplecache/ cache

If your webserver supports following symlinks, this will serve files straight off disk without booting up PHP each time.

For security reasons, some webservers (e.g. Apache in version 2.4) might follow the symlinks by default only if the owner of the symlink source and target match. If the cache symlink fails to work on your server, you can change the owner of the cache symlink itself (and not the /views_simplecache/ directory) with

cd /path/to/wwwroot/
chown -h wwwrun:www cache

In this example it’s assumed that the /views_simplecache/ directory in the data directory is owned by the wwwrun account that belongs to the www group. If this is not the case on your server, you have to modify the chown command accordingly.

System cache ¶

The location of views are cached so that they do not have to be discovered (profiling indicated that page load took a non-linear amount of time the more plugins were enabled due to view discovery). Elgg also caches information like the language mapping and class map.

This can be disabled by setting $CONFIG->system_cache_enabled = false; For best performance, make sure this value is set to true.

This is currently stored in files in your dataroot (although later versions of Elgg may use memcache). As with the simple cache it is flushed when a plugin is enabled, disabled or reordered, or when upgrade.php is executed.

The system cache can be disabled via the administration menu, and it is recommended that you do this on your development platform if you are writing Elgg plugins.

Boot cache ¶

Elgg has the ability to cache numerous resources created and fetched during the boot process. To configure how long this cache is valid you must set a TTL in your settings.php file: $CONFIG->boot_cache_ttl = 3600;

Look at the Stash documentation for more info about the TTL.

Database query cache ¶

For the lifetime of a given page’s execution, a cache of all SELECT queries is kept. This means that for a given page load a given select query will only ever go out to the database once, even if it is executed multiple times. Any write to the database will flush this cache, so it is advised that on complicated pages you postpone database writes until the end of the page or use the execute_delayed_* functionality. This cache will be automatically cleared at the end of a page load.

You may experience memory problems if you use the Elgg framework as a library in a PHP CLI script. This can be disabled by setting $CONFIG->db_disable_query_cache = true;

Etags and Expires headers ¶

These technologies tell your users‘ browsers to cache static assets (CSS, JS, images) locally. Having these enabled greatly reduces server load and improves user-perceived performance.

Use the Firefox yslow plugin or Chrome DevTools Audits to confirm which technologies are currently running on your site.

If the static assets aren’t being cached:

Verify that you have these extensions installed and enabled on your host
Update your .htaccess file, if you are upgrading from a previous version of Elgg
Enable Simplecache, which turns select views into browser-cacheable assets

Memcached ¶

Libmemcached was created by Brian Aker and was designed from day one to give the best performance available to users of Memcached.

Siehe auch

http://libmemcached.org/About.html and https://secure.php.net/manual/en/book.memcached.php

Installation requirements:

php-memcached
libmemcached
memcached

Configuration:

Uncomment and populate the following sections in settings.php

$CONFIG->memcache = true;

$CONFIG->memcache_servers = array (
    array('server1', 11211),
    array('server2', 11211)
);

Optionaly if you run multiple Elgg installations but use ony one Memcache server, you may want to add a namespace prefix. In order to do this, uncomment the following line

$CONFIG->memcache_namespace_prefix = '';

Squid ¶

We have had good results by using Squid to cache images for us.

Bytecode caching ¶

There are numerous PHP code caches available on the market. These speed up your site by caching the compiled byte code from your script meaning that your server doesn’t have to compile the PHP code each time it is executed.

Direct file serving ¶

If your server can be configured to support the X-Sendfile or X-Accel headers, you can configure it to be used in settings.php. This allows your web server to directly stream files to the client instead of using PHP’s readfile().

Composer Autoloader Optimization ¶

The Composer autoloader is responsible for loading classes provided by dependencies of Elgg. The way the autoloader works is it searches for a classname in the installed dependencies. While this is mostly a fast process it can be optimized.

You can optimize the autoloader 2 different ways. The first is in the commandline, the other is in the composer.json of your project.

If you want to optimize the autoloader using the commandline use the -o flag. The disadvantage is you have to add the -o flag every time you run Composer.

# During the installation
composer install -o

# Or during the upgrade process
composer upgrade -o

The second option is to add the optimization to your composer.json file, that way you never forget it.

{
        "config": {
                "optimize-autoloader": true,
                "apcu-autoloader": true
        }
}

Siehe auch

Check out the Autoloader Optimization page for more information about how to optimize the Composer autoloader.

Bemerkung

As of Elgg 3.0 all the downloads of Elgg from the website have the optimized autoloader.

Hosting ¶

Don’t expect to run a site catering for millions of users on a cheap shared host. You will need to have your own host hardware and access over the configuration, as well as lots of bandwidth and memory available.

Memory, CPU and bandwidth ¶

Due to the nature of caching, all caching solutions will require memory. It is a fairly cheap return to throw memory and CPU at the problem.

On advanced hardware it is likely that bandwidth is going to be your bottleneck before the server itself. Ensure that your host can support the load you are suggesting.

Configuration ¶

Lastly, take a look at your configuration as there are a few gotchas that can catch people.

For example, out of the box, Apache can handle quite a high load. However, most distros of Linux come with mysql configured for small sites. This can result in Apache processes getting stalled waiting to talk to one very overloaded MySQL process.

Check for poorly-behaved plugins ¶

Plugins can be programmed in a very naive way and this can cause your whole site to feel slow.

Try disabling some plugins to see if that noticeably improves performance. Once you’ve found a likely offender, go to the original plugin author and report your findings.

Use client-rendered HTML ¶

We’ve found that at a certain point, much of the time spent on the server is simply building the HTML of the page with Elgg’s views system.

It’s very difficult to cache the output of templates since they can generally take arbitrary inputs. Instead of trying to cache the HTML output of certain pages or views, the suggestion is to switch to an HTML-based templating system so that the user’s browser can cache the templates themselves. Then have the user’s computer do the work of generating the output by applying JSON data to those templates.

This can be very effective, but has the downside of being significant extra development cost. The Elgg team is looking to integrate this strategy into Elgg directly, since it is so effective especially on pages with repeated or hidden content.

Cron¶

Contents

What does it do?
How does it work?

What does it do?¶

Cron is a program available on Unix-based operating systems that enables users to run commands and scripts at set intervals or at specific times.

Elgg’s cron handler allows administrators and plugin developers to setup jobs that need to be executed at set intervals.

Most common examples of cron jobs in Elgg include:

sending out queued notifications

rotating the system log in the database

collecting garbage in the database (compacting the database by removing entries that are no longer required)

Plugins can add jobs by registering a plugin hook handler for one of the following cron intervals:

minute - Run every minute

fiveminute - Run every 5 minutes

fifteenmin - Run every 15 minutes

halfhour - Run every 30 minutes

hourly - Run every hour

daily - Run every day

weekly - Run every week

monthly - Run every month

yearly - Run every year

elgg_register_plugin_hook_handler('cron', 'hourly', function() {

   $events = my_plugin_get_upcoming_events();

   foreach ($events as $event) {
      $attendees = $event->getAttendees();

      // notify
   }
});

How does it work?¶

crontab must be setup in such a way as to activate Elgg cron handler every minute, or at a specific interval. Once cron tab activates the cron job, Elgg executes all hook handlers attached to that interval.

If you have SSH access to your Linux servers, type crontab -e and add your crontab configuration.

* * * * * path/to/phpbin path/to/elgg/elgg-cli cron -q

The above command will run every minute and activate all due cron jobs.

Optionally you can activate handlers for a specific interval:

0 * * * * path/to/phpbin path/to/elgg/elgg-cli cron -i hourly -q

More information about cron can be found at:

Backup and Restore¶

Contents

Introduction
- Why
- What
- Assumptions
Creating a usable backup - automatically
Restoring from backup
Congratulations!
Related

Introduction ¶

Why ¶

Shared hosting providers typically don’t provide an automated way to backup your Elgg installation. This article will address a method of accomplishing this task.

In IT there are often many ways to accomplish the same thing. Keep that in mind. This article will explain one method to backup and restore your Elgg installation on a shared hosting provider that uses the CPanel application. However, the ideas presented here can be tailored to other applications as well. The following are typical situations that might require a procedure such as this:

Disaster Recovery
Moving your Elgg site to a new host
Duplicating an installation

What ¶

Topics covered:

Full backups of the Elgg directories and MySQL databases are performed daily (automated)
The backups are sent to an off-site location via FTP (automated)
The local backups are deleted after successful transfer to the off-site location (automatic)
Five days of backups will be maintained (automated)
Restoration of data to the new host (manual)

This process was composed with assistance from previous articles in the Elgg documentation wiki.

Assumptions ¶

The following assumptions have been made:

The Elgg program directory is /home/userx/public_html
The Elgg data directory is /home/userx/elggdata
You’ve created a local directory for your backups at /home/userx/sitebackups
You have an off-site FTP server to send the backup files to
The directory that you will be saving the off-site backups to is /home/usery/sitebackups/
You will be restoring the site to a second shared hosting provider in the /home/usery/public_html directory

Wichtig

Be sure to replace userx, usery, http://mynewdomain.com and all passwords with values that reflect your actual installation!

Creating a usable backup - automatically ¶

Customize the backup script ¶

The script that you will use can be found here .

Just copy the script to a text file and name the file with a .pl extension. You can use any text editor to update the file.

Change the following to reflect your directory structure:

# ENTER THE PATH TO THE DIRECTORY YOU WANT TO BACKUP, NO TRAILING SLASH
$directory_to_backup = '/home/userx/public_html';
$directory_to_backup2 = '/home/userx/elggdata';
# ENTER THE PATH TO THE DIRECTORY YOU WISH TO SAVE THE BACKUP FILE TO, NO TRAILING SLASH
$backup_dest_dir = '/home/userx/sitebackups';

Change the following to reflect your database parameters:

# MYSQL BACKUP PARAMETERS
$dbhost = 'localhost';
$dbuser = 'userx_elgg';
$dbpwd = 'dbpassword';
# ENTER DATABASE NAME
$database_names_elgg = 'userx_elgg';

Change the following to reflect your off-site FTP server parameters:

# FTP PARAMETERS
$ftp_host = "FTP HOSTNAME/IP";
$ftp_user = "ftpuser";
$ftp_pwd = "ftppassword";
$ftp_dir = "/";

Save the file with the .pl extension (for the purposes of this article we will name the file: elgg-ftp-backup-script.pl) and upload it to the following directory /home/userx/sitebackups

Be aware that you can turn off FTP and flip a bit in the script so that it does not delete the local backup file in the event that you don’t want to use off-site storage for your backups.

Configure the backup Cron job ¶

Login to your CPanel application and click on the „Cron Jobs“ link. In the Common Settings dropdown choose „Once a day“ and type the following in the command field /usr/bin/perl /home/userx/sitebackups/elgg-ftp-backup-script.pl

Click on the „Add New Cron Job“ button. Daily full backups are now scheduled and will be transferred off-site.

Configure the cleanup Cron job ¶

If you are sending your backups, via FTP, to another shared hosting provider that uses the CPanel application or you’ve turned off FTP altogether you can configure your data retention as follows.

Login to your CPanel application for your FTP site, or locally if you’re not using FTP, and click on the „Cron Jobs“ link. In the Common Settings dropdown choose „Once a day“ and type the following in the command field find /home/usery/sitebackups/full_* -mtime +4 -exec rm {} \;

The -mtime X parameter will set the number of days to retain backups. All files older than x number of days will be deleted. Click on the „Add New Cron Job“ button. You have now configured your backup retention time.

Restoring from backup ¶

Prepare your backup files ¶

The assumption is that you’re restoring your site to another shared hosting provider with CPanel.

When the script backed the files up the original directory structure was maintained in the zip file. We need to do a little cleanup. Perform the following:

Download the backup file that you wish to restore from
Extract the contents of the backup file
Drill down and you will find your site backup and SQL backup. Extract both of these. You will then have:
- a MySQL dump file with a .sql extension
- another directory structure with the contents of:
  
  /home/userx/public_html
  
  /home/userx/elggdata
Repackage the contents of the /home/userx/public_html directory as a zip file so that the files are in the root of the zip file
- The reason for doing this is simple. It’s much more efficient to upload one zip file than it is to ftp the contents of the /home/userx/public_html directory to your new host.
Repackage the contents of the /home/userx/elggdata directory as a zip file so that the files are in the root of the zip file

You should now have the following files:

the .sql file
the zip file with the contents of /home/userx/public_html in the root
the zip file with the contents of /home/userx/elggdata in the root

Restore the files ¶

This is written with the assumption that you’re restoring to a different host but maintaining the original directory structure. Perform the following:

Login to the CPanel application on the host that you wish to restore the site to and open the File Manager.
Navigate to /home/usery/public_html
- Upload the zip file that contains the /home/userx/public_html files
- Extract the zip file
  
  You should now see all of the files in /home/usery/public_html
- Delete the zip file
Navigate to /home/usery/elggdata
- Upload the zip file that contains the /home/userx/elggdata files
- Extract the zip file
  
  You should now see all of the files in /home/usery/elggdata
- Delete the zip file

Program and data file restoration is complete

Restore the MySQL Database ¶

Bemerkung

Again, the assumption here is that you’re restoring your Elgg installation to a second shared hosting provider. Each shared hosting provider prepends the account holder’s name to the databases associated with that account. For example, the username for our primary host is userx so the host will prepend userx_ to give us a database name of userx_elgg. When we restore to our second shared hosting provider we’re doing so with a username of usery so our database name will be usery_elgg. The hosting providers don’t allow you to modify this behavior. So the process here isn’t as simple as just restoring the database from backup to the usery account. However, having said that, it’s not terribly difficult either.

Edit the MySQL backup ¶

Open the .sql file that you extracted from your backup in your favorite text editor. Comment out the following lines with a hash mark:

#CREATE DATABASE /*!32312 IF NOT EXISTS*/ `userx_elgg` /*!40100 DEFAULT CHARACTER SET latin1 */;
#USE `userx_elgg`;

Save the file.

Create the new database ¶

Perform the following:

Login to the CPanel application on the new host and click on the „MySQL Databases“ icon
- Fill in the database name and click the „create“ button. For our example we are going to stick with elgg which will give us a database name of usery_elgg
- You can associate an existing user with the new database, but to create a new user you will need to:
  
  Go to the „Add New User“ section of the „MySQL Databases“ page
  
  Enter the username and password. For our example we’re going to keep it simple and use elgg once again. This will give us a username of usery_elgg
- Associate the new user with the new database
  
  Go to the „Add User To Database“ section of the „MySQL Databases“ page. Add the usery_elgg user to the usery_elgg database
  
  Select „All Privileges“ and click the „Make Changes“ button

Restore the production database ¶

Now it’s time to restore the MySQL backup file by importing it into our new database named „usery_elgg“.

Login to the CPanel application on the new host and click on the „phpMyAdmin icon
- Choose the usery_elgg database in the left hand column
- Click on the „import“ tab at the top of the page
- Browse to the .sql backup on your local computer and select it
- Click the „Go“ button on the bottom right side of the page

You should now see a message stating that the operation was successful

Bringing it all together ¶

The restored elgg installation knows nothing about the new database name, database username, directory structure, etc. That’s what we’re going to address here.

Edit /public_html/elgg-config/settings.php on the new hosting provider to reflect the database information for the database that you just created.

// Database username
$CONFIG->dbuser = 'usery_elgg';

// Database password
$CONFIG->dbpass = 'dbpassword';

// Database name
$CONFIG->dbname = 'usery_elgg';

// Database server
// (For most configurations, you can leave this as 'localhost')
$CONFIG->dbhost = 'localhost';

// (For most configurations, you can leave this as 3306)
$CONFIG->dbport = 3306;

$CONFIG->wwwroot = 'http://your.website.com/'

Upload the settings.php file back to the new host - overwriting the existing file.

Open the phpMyAdmin tool on the new host from the CPanel. Select the usery_elgg database on the left and click the SQL tab on the top of the page. Run the following SQL queries against the usery_elgg database:

Change the installation path

UPDATE `elgg_config` SET `value` = REPLACE(`value`, "/home/userx/public_html/grid/", "/home/usery/public_html/grid/") WHERE `name` = "path";

Change the data directory

UPDATE `elgg_config` SET `value` = REPLACE(`value`, "/home/userx/elggdata/", "/home/usery/elggdata/") WHERE `name` = "dataroot";

Change the filestore data directory

UPDATE elgg_metadata set value = '/home/usery/elggdata/' WHERE name = 'filestore::dir_root';

Finalizing the new installation ¶

Run the upgrade script by visiting the following URL: http://mynewdomain.com/upgrade.php . Do this step twice - back to back.

Update your DNS records so that your host name resolves to the new host’s IP address if this is a permanent move.

Congratulations!¶

If you followed the steps outlined here you should now have a fully functional copy of your primary Elgg installation.

Getting Help¶

Having a problem with Elgg? The best way to get help is to ask at the Community Site. This site is community supported by a large group of volunteers. Here are a few tips to help you get the help you need.

Contents

Getting help
Guidelines
Good Ideas

Getting help ¶

Don’t be a Help Vampire ¶

We were all newbies at one time, but we can all learn. Not showing that you are making attempts to learn on your own or do your own research is off putting for those helping. Also, very generic questions like „How do I build a forum?“ are almost impossible to answer.

Search first¶

Be sure to search the documentation (this site), the Community Site, and Google before asking a question. New users to Elgg frequently have the same questions, so please search. People are less inclined to reply to a post that has been answered many other times or that can be answered easily by Googling.

Ask once¶

Posting the same questions in multiple places makes it hard to answer you. Ask your question in one place only. Duplicate questions may be moderated.

Include Elgg Version¶

Different versions of Elgg have different features (and different bugs). Including the version of Elgg that you are using will help those helping you.

Have a reasonable profile¶

Profiles that look like spam or have silly names will often be ignored. Joviality is fine, but people are more likely to help Michael than 1337elggHax0r.

Post in the appropriate forum¶

Check to make sure you’re posting in the right forum. If you have a question about creating a plugin, don’t post to the Elgg Feedback forum. If you need help installing Elgg, post to Technical Support instead of the Theming group.

Use a descriptive topic title¶

Good topic titles concisely describe your problem or question. Bad topic titles are vague, contain all capital letters, and excessive punctuation.

Good title: „White screen after upgrading to 1.7.4.“

Bad title: „URGENT!!!!! site broke ;-( losing money help!!!!!!!!!!!“

Be detailed¶

Include as many details about your problem as possible. If you have a live site, include a link. Be forthcoming if community members might ask for more information. We can’t help you if you won’t give any details!

Keep it public¶

This is a public forum for the good of the Elgg project. Keep posts public. There’s no reason for anyone to ask you to send a private message or email. Likewise, there’s no reason to ask anyone to send a private email to you. Post in the public.

Guidelines ¶

In addition to the site-wide Terms and Policies, following these guidelines keeps our community site useful and safe for everyone.

Content¶

All content must be safe for work: PG in the US and UK. If your Elgg site has adult content and you have been asked to post a link, please mark it NSFW (Not Safe For Work) so people know.

Excessive swearing in any language will not be tolerated.

Mood¶

Working with technical problems can be frustrating. Please keep the community site free of frustration. If you’re feeling anxious, take a step away and do something else. Threatening or attacking community members, core developers, or plugin developers will not help solve your problem and will likely get you banned.

Advertising¶

Advertising is not allowed. Posts with any sort of advertising will be moderated.

Asking for money / Offering to pay¶

Don’t ask for money on the community site. Likewise, don’t offer to pay for answers. If you are looking for custom development, post to the Professional Services group. Posts asking for money or recommending a commercial plugin may be moderated.

Links¶

If you’re having a problem with a live site, please provide a link to it.

That said, the community site is not a back linking service or SEO tool. Excessive linking will be moderated and your account may be banned.

Signatures¶

There’s a reason Elgg doesn’t have an option for signatures: they cause clutter and distract from the conversation. Users are discouraged from using signatures on the community site, and signatures with links or advertising will be removed.

Bumping, +1, me too¶

Don’t do it. If your question hasn’t been answered, see the top of this document for tips. These types of post add nothing to the conversation and may be moderated.

Posting Code¶

Long bits of code are confusing to read through in a forums context. Please use http://elgg.pastebin.com to post long bits of code and provide the Paste Bin link instead of directly posting the code.

Good Ideas ¶

Not policies, but good ideas.

Say thanks¶

Did someone help you? Be sure to thank them! The community site is run by volunteers. No one has to help you with your problem. Be sure to show your appreciation!

Give back¶

Have a tip for Elgg? See someone with a similar problem you had? You’ve been there and can help them out, so give them a hand!

Security¶

As of Elgg 3.0 several hardening settings have been added to Elgg. You can enable/disable these settings as you like.

Contents

Upgrade protection
Cron protection
Disable password autocomplete
Email address change requires password
Email address change requires confirmation
Session bound icons
Notification to site administrators
Notifications to user
- Site administrator
- (Un)ban
Minimal username length
Minimal password requirements

Upgrade protection ¶

The URL of http://your-elgg-site.com/upgrade.php can be protected by a unique token. This will prevent random users from being able to run this file. The token is not needed for logged in site administrators.

Cron protection ¶

The URLs of the cron can be protected by a unique token. This will prevent random users from being able to run the cron. The token is not needed when running the cron from the commandline of the server.

Disable password autocomplete ¶

Data entered in these fields will be cached by the browser. An attacker who can access the victim’s browser could steal this information. This is especially important if the application is commonly used in shared computers such as cyber cafes or airport terminals. If you disable this, password management tools can no longer autofill these fields. The support for the autocomplete attribute can be browser specific.

Email address change requires password ¶

When a user wishes to change their email address associated with their account, they need to also supply their current password.

Email address change requires confirmation ¶

When a user wishes to change their email address associated with their account, they need to confirm the new email address. This is done by sending an email to the new address with a validation link. After clicking this link the new email address will be used.

Session bound icons ¶

Entity icons can be session bound by default. This means the URLs generated also contain information about the current session. Having icons session bound makes icon urls not shareable between sessions. The side effect is that caching of these urls will only help the active session.

Notification to site administrators ¶

When a new site administrator is added or when a site administrator is removed all the site administrators get a notification about this action.

Notifications to user ¶

Site administrator ¶

When the site administrator role is added to or removed from the account, send a notification to the user whos account this is affecting.

(Un)ban ¶

When the account of a user gets banned or unbanned, let the affected user know about this action.

Minimal username length ¶

You can configure the minimal length the username should have upon registration of a user.

Minimal password requirements ¶

You can configure several requirements for new passwords of the users

length: the password should be at least x characters long
lower case: minimal number of lower case (a-z) characters in the password
upper case: minimal number of upper case (A-Z) characters in the password
numbers: minimal number of numbers (0-9) characters in the password
specials: minimal number of special (like !@#$%^&*(), etc.) characters in the password

User validation¶

Plugins can influence how users are validated before they can use the website.

Contents

Listing of unvalidated users
Require admin validation

Listing of unvalidated users ¶

In the Admin section of the website is a list of all unvalidated users. Some actions can be taken on the users, like delete them from the system or validate them.

Plugins have the option to add additional features to this list.

Siehe auch

An example of this is the User validation by e-mail plugin which doesn’t allow users onto the website until their e-mail address is validated.

Require admin validation ¶

In the Site settings under the Users section there is a setting which can be enabled to require admin validation of a new user account before the user can use their account. After registration the user gets notified that their account is awaiting validation by an administrator.

Site administrators can receive an e-mail notification that there are users awaiting validation.

After validation the user is notified that they can use their account.

Spam¶

Keep spam under control.

Spam is a very common problem that admins need to deal with and which we aim to improve in core, but there are some actions site admins can take to mitigate the problem.

Install an anti-spam plugin¶

There are several available on the community

http://community.elgg.org/plugins/search?f[c][]=spam&sb=Search

Change the registration url¶

Some have said they have good success changing the registration URL, since the spammers are naive bots and can no longer find where to create the fake accounts.

Disable open registration¶

If the flow of registrations is low enough, you can vet all users that come in to keep the quality of interaction high.

Contribute to anti-spam measures in core¶

https://github.com/Elgg/Elgg/issues?labels=spam&state=open

Developer Guides¶

Customize Elgg’s behavior with plugins.

Don’t Modify Core¶

Warnung

In general, you shouldn’t modify non-config files that come with third-party software like Elgg.

The best way to customize the behavior of Elgg is to install Elgg as a composer dependency and use the root directory to store modifications specific to your application, and alter behavior through the rich Elgg plugin API.

If you’d like to share customizations between sites or even publish your changes as a reusable package for the community, create a plugin using the same plugin APIs and file structure.

It makes it hard to get help¶

When you don’t share the same codebase as everyone else, it’s impossible for others to know what is going on in your system and whether your changes are to blame. This can frustrate those who offer help because it can add considerable noise to the support process.

It makes upgrading tricky and potentially disastrous¶

You will certainly want or need to upgrade Elgg to take advantage of

security patches

new features

new plugin APIs

new stability improvements

performance improvements

If you’ve modified core files, then you must be very careful when upgrading that your changes are not overwritten and that they are compatible with the new Elgg code. If your changes are lost or incompatible, then the upgrade may remove features you’ve added and even completely break your site.

This can also be a slippery slope. Lots of modifications can lead you to an upgrade process so complex that it’s practically impossible. There are lots of sites stuck running old versions software due to taking this path.

It may break plugins¶

You may not realize until much later that your „quick fix“ broke seemingly unrelated functionality that plugins depended on.

Summary¶

Resist the temptation

Editing existing files is quick and easy, but doing so heavily risks the maintainability, security, and stability of your site.
When receiving advice, consider if the person telling you to modify core will be around to rescue you if you run into trouble later!
Apply these principle to software in general.

If you can avoid it, don’t modify third party plugins either, for the same reasons: Plugin authors release new versions, too, and you will want those updates.

Access Control Lists¶

An Access Control List (or ACL) can grant one or more users access to an entity or annotation in the database.

Contents

Creating an ACL
ACL subtypes
Adding users to an ACL
Removing users from an ACL
Retrieving an ACL
Read access
Ignoring access

Siehe auch

Database Access Control

Creating an ACL ¶

An access collection can be create by using the function create_access_collection().

$owner_guid = elgg_get_logged_in_user_guid();

$acl = create_access_collection("Sample name", $owner_guid, 'collection_subtype');

ACL subtypes ¶

ACLs can have a subtype, this is to help differentiate between the usage of the ACL. It’s higly recommended to set a subtype for an ACL.

Elgg core has three examples of subtype usage

group_acl an ACL owned by an ElggGroup which grants group members access to content shared with the group
friends an ACL owned by an ElggUser which grant friends of a user access to content shared with friends
friends_collection an ACL owned by an ElggUser which grant specific friends access to content shared with the ACL

Adding users to an ACL ¶

If you have an ACL you still need to add users to it in order to grant those users access to content with the access_id of the ACLs id.

// creating an ACL
$owner_guid = elgg_get_logged_in_user_guid();

$acl_id = create_access_collection("Sample name", $owner_guid, 'collection_subtype');

// add other user (procedural style)
add_user_to_access_collection($some_user_guid, $acl_id);

// add other user (object oriented style)
/* @var $acl ElggAccessCollection */
$acl = get_access_collection($acl_id);

$acl->addMember($some_other_user_guid);

Removing users from an ACL ¶

If you no longer wish to allow access for a given user in an ACL you can easily remove that user from the list.

// remove a user from an ACL (procedural style)
remove_user_from_access_collection($user_guid_to_be_removed, $acl_id);

// remove a user from an ACL (object oriented style)
/* @var $acl ElggAccessCollection */
$acl = get_access_collection($acl_id);

$acl->removeMember(user_guid_to_be_removed);

Retrieving an ACL ¶

In order to manage an ACL, or add the ID of an ACL to an access list there are several functions available to retrieve an ACL from the database.

// get ACL based on known id
$acl = get_access_collection($acl_id);

// get all ACLs of an owner (procedural style)
$acls = elgg_get_access_collections([
        'owner_guid' => $some_owner_guid,
]);

// get all ACLs of an owner (object oriented style)
$acls = $some_owner_entity->getOwnedAccessCollections();

// add a filter for ACL subtype
// get all ACLs of an owner (procedural style)
$acls = elgg_get_access_collections([
        'owner_guid' => $some_owner_guid,
        'subtype' => 'some_subtype',
]);

// get all ACLs of an owner (object oriented style)
$acls = $some_owner_entity->getOwnedAccessCollections([
        'subtype' => 'some_subtype',
]);

// get one ACL of an owner (object oriented style)
// for example the group_acl of an ElggGroup
// Returns the first ACL owned by the entity with a given subtype
$acl = $group_entity->getOwnedAccessCollection('group_acl');

Read access ¶

The access system of Elgg automaticly adds all the ACLs a user is a member of to the access checks. For example a user is a member of a group and is friends with 3 other users, all the corresponding ACLs are added in order to check access to entities when retrieving them (eg. listing all blogs).

Ignoring access ¶

If for some case you need entities retrieved ignoring the access rules you can wrap your code in elgg_call. There are different flags you can use.

ELGG_IGNORE_ACCESS: no access rules are applied

ELGG_ENFORCE_ACCESS: access rules are forced to be applied

ELGG_SHOW_DISABLED_ENTITIES: will retrieve entities that are disabled

ELGG_HIDE_DISABLED_ENTITIES: will never retrieve entities that are disabled

$options = [
        'type' => 'user'
];

$entities = elgg_call(ELGG_IGNORE_ACCESS, function() use ($options) {
        return elgg_get_entities($options);
});

You can also combine flags.

$entities = elgg_call(ELGG_IGNORE_ACCESS | ELGG_SHOW_DISABLED_ENTITIES, function() {
        return elgg_get_entities([
                'type' => 'user'
        ]);
});

Accessibility¶

This page aims to list and document accessibility rules and best practices, to help core and plugins developpers to make Elgg the most accessible social engine framework that everyone dreams of.

Bemerkung

This is an ongoing work, please contribute on Github if you have some skills in this field!

Resources + references¶

Official WCAG Accessibility Guidelines Overview
Official WCAG Accessibility Guidelines
Resources for planning and implementing for accessibility
Practical tips from the W3C for improving accessibility
Preliminary review of websites for accessibility
Tools for checking the accessibility of websites
List of practical techniques for implementing accessibility (It would be great if someone could go through this and filter out all the ones that are relevant to Elgg)

Tips for implementing accessibility¶

All accessibility-related tickets reported to trac should be tagged with „a11y“, short for „accessibility“
Use core views such as output/*, and input/* to generate markup, since we can bake a11y concerns into these views
All images should have a descriptive alt attribute. Spacer or purely decorative graphics should have blank alt attributes
All <a> tags should have text or an accessible image inside. Otherwise screen readers will have to read the URL, which is a poor experience <a> tags should contain descriptive text, if possible, as opposed to generic text like „Click here“
Markup should be valid
Themes should not reset „outline“ to nothing. :focus deserves a special visual treatment so that handicapped users can know where they are

Tips for testing accessibility¶

Use the tools linked to from the resources section. Example report for community.elgg.org on June 16, 2012
Try different font-size/zoom settings in your browser and make sure the theme remains usable
Turn off css to make sure the sequential order of the page makes sense

Documentation objectives and principles¶

Main accessibility rules
collect and document best practices
Provide code examples
Keep the document simple and usable
Make it usable for both beginner developpers and experts (from most common and easiest changes to elaborate techniques)

Forms + Actions¶

Create, update, or delete content.

Elgg forms submit to actions. Actions define the behavior for form submission.

This guide assumes basic familiarity with:

Contents

Registering actions ¶

Actions must be registered before use.

There are two ways to register actions:

Using elgg_register_action()

elgg_register_action("example", __DIR__ . "/actions/example.php");

The mod/example/actions/example.php script will now be run whenever a form is submitted to http://localhost/elgg/action/example.

Use elgg-plugin.php

return [
   'actions' => [
      // defaults to using an action file in /actions/myplugin/action_a.php
      'myplugin/action_a' => [
         'access' => 'public',
      ],

      // define custom action path
      'myplugin/action_b' => [
         'access' => 'admin',
         'filename' => __DIR__ . '/actions/action.php'
      ],

      // define a controller
      'myplugin/action_c' => [
         'controller' => \MyPlugin\Actions\ActionC::class,
      ],
   ],
];

Warnung

A stumbling point for many new developers is the URL for actions. The URL always uses /action/ (singular) and never /actions/ (plural). However, action script files are usually saved under the directory /actions/ (plural) and always have an extension. Use elgg_generate_action_url() to avoid confusion.

Registering actions using plugin config file ¶

You can also register actions via the elgg-plugin config file. To do this you need to provide an action section in the config file. The location of the action files are assumed to be in the plugin folder /actions.

<?php

return [
        'actions' => [
            'blog/save' => [], // all defaults
            'blog/delete' => [ // all custom
                  'access' => 'admin',
                  'filename' => __DIR__ . 'actions/blog/remove.php',
            ],
        ],
];

Permissions ¶

By default, actions are only available to logged in users.

To make an action available to logged out users, pass "public" as the third parameter:

elgg_register_action("example", $filepath, "public");

To restrict an action to only administrators, pass "admin" for the last parameter:

elgg_register_action("example", $filepath, "admin");

Writing action files ¶

Use the get_input() function to get access to request parameters:

$field = get_input('input_field_name', 'default_value');

You can then use the Database api to load entities and perform actions on them accordingly.

To indicate a successful action, use elgg_ok_response(). This function accepts data that you want to make available to the client for XHR calls (this data will be ignored for non-XHR calls)

$user = get_entity($guid);
// do something

$action_data = [
   'entity' => $user,
   'stats' => [
       'friends' => $user->getFriends(['count' => true]);
   ],
];

return elgg_ok_response($action_data, 'Action was successful', 'url/to/forward/to');

To indicate an error, use elgg_error_response()

$user = elgg_get_logged_in_user_entity();
if (!$user) {
   // show an error and forward the user to the referring page
   // send 404 error code on AJAX calls
   return elgg_error_response('User not found', REFERRER, ELGG_HTTP_NOT_FOUND);
}

if (!$user->canEdit()) {
   // show an error and forward to user's profile
   // send 403 error code on AJAX calls
   return elgg_error_response('You are not allowed to perform this action', $user->getURL(), ELGG_HTTP_FORBIDDEN);
}

Customizing actions ¶

Before executing any action, Elgg triggers a hook:

$result = elgg_trigger_plugin_hook('action:validate', $action, null, true);

Where $action is the action being called. If the hook returns false then the action will not be executed. Don’t return anything if your validation passes.

Example: Captcha¶

The captcha module uses this to intercept the register and user/requestnewpassword actions and redirect them to a function which checks the captcha code. This check returns false if the captcha validation fails (which prevents the associated action from executing).

This is done as follows:

elgg_register_plugin_hook_handler("action:validate", "register", "captcha_verify_action_hook");
elgg_register_plugin_hook_handler("action:validate", "user/requestnewpassword", "captcha_verify_action_hook");

...

function captcha_verify_action_hook(\Elgg\Hook $hook) {
  $token = get_input('captcha_token');
  $input = get_input('captcha_input');

  if (($token) && (captcha_verify_captcha($input, $token))) {
    return;
  }

  register_error(elgg_echo('captcha:captchafail'));

  return false;
}

This lets a plugin extend an existing action without the need to replace the whole action. In the case of the captcha plugin it allows the plugin to provide captcha support in a very loosely coupled way.

Actions available in core ¶

`entity/delete`¶

If your plugin does not implement any custom logic when deleting an entity, you can use bundled delete action

$guid = 123;
// You can provide optional forward path as a URL query parameter
$forward_url = 'path/to/forward/to';
echo elgg_view('output/url', array(
   'text' => elgg_echo('delete'),
   'href' => elgg_generate_action_url('entity/delete', [
     'guid' => $guid,
     'forward_url' => $forward_url,
   ]),
   'confirm' => true,
));

You can customize the success message keys for your entity type and subtype, using "entity:delete:$type:$subtype:success" and "entity:delete:$type:success" keys.

// to add a custom message when a blog post or file is deleted
// add the translations keys in your language files
return [
   'entity:delete:object:blog:success' => 'Blog post has been deleted,
   'entity:delete:object:file:success' => 'File titled %s has been deleted',
];

Forms ¶

To output a form, use the elgg_view_form function like so:

echo elgg_view_form('example');

Doing this generates something like the following markup:

<form action="http://localhost/elgg/action/example">
  <fieldset>
    <input type="hidden" name="__elgg_ts" value="1234567890" />
    <input type="hidden" name="__elgg_token" value="3874acfc283d90e34" />
  </fieldset>
</form>

Elgg does some things automatically for you when you generate forms this way:

It sets the action to the appropriate URL based on the name of the action you pass to it

It adds some anti-csrf tokens (__elgg_ts and __elgg_token) to help keep your actions secure

It automatically looks for the body of the form in the forms/example view.

Put the content of your form in your plugin’s forms/example view:

// /mod/example/views/default/forms/example.php
echo elgg_view('input/text', array('name' => 'example'));

// defer form footer rendering
// this will allow other plugins to extend forms/example view
elgg_set_form_footer(elgg_view('input/submit'));

Now when you call elgg_view_form('example'), Elgg will produce:

<form action="http://localhost/elgg/action/example">
  <fieldset>
    <input type="hidden" name="__elgg_ts" value="...">
    <input type="hidden" name="__elgg_token" value="...">

    <input type="text" class="elgg-input-text" name="example">
    <div class="elgg-foot elgg-form-footer">
        <input type="submit" class="elgg-button elgg-button-submit" value="Submit">
    </div>
  </fieldset>
</form>

Inputs ¶

To render a form input, use one of the bundled input views, which cover all standard HTML input elements. See individual view files for a list of accepted parameters.

echo elgg_view('input/select', array(
   'required' => true,
   'name' => 'status',
   'options_values' => [
      'draft' => elgg_echo('status:draft'),
      'published' => elgg_echo('status:published'),
   ],
   // most input views will render additional parameters passed to the view
   // as tag attributes
   'data-rel' => 'blog',
));

The above example will render a dropdown select input:

<select required="required" name="status" data-rel="blog" class="elgg-input-select">
   <option value="draft">Draft</option>
   <option value="published">Published</option>
</select>

To ensure consistency in field markup, use elgg_view_field(), which accepts all the parameters of the input being rendered, as well as #label and #help parameters (both of which are optional and accept HTML or text).

echo elgg_view_field([
   '#type' => 'select',
   '#label' => elgg_echo('blog:status:label'),
   '#help' => elgg_view_icon('help') . elgg_echo('blog:status:help'),
   'required' => true,
   'name' => 'status',
   'options_values' => [
      'draft' => elgg_echo('status:draft'),
      'published' => elgg_echo('status:published'),
   ],
   'data-rel' => 'blog',
]);

The above will generate the following markup:

<div class="elgg-field elgg-field-required">
   <label for="elgg-field-1" class="elgg-field-label">Blog status<span title="Required" class="elgg-required-indicator">*</span></label>
   <div class="elgg-field-input">
      <select required="required" name="status" data-rel="blog" id="elgg-field-1" class="elgg-input-select">
         <option value="draft">Draft</option>
         <option value="published">Published</option>
      </select>
   </div>
   <div class="elgg-field-help elgg-text-help">
      <span class="elgg-icon-help elgg-icon"></span>This indicates whether or not the blog is visible in the feed
   </div>
</div>

Input types ¶

A list of bundled input types/views:

input/text - renders a text input <input type="text">
input/plaintext - renders a textarea <textarea></textarea>
input/longtext - renders a WYSIWYG text input
input/url - renders a url input <input type="url">
input/email - renders an email input <input type="email">
input/checkbox - renders a single checkbox <input type="checkbox">
input/checkboxes - renders a set of checkboxes with the same name
input/radio - renders one or more radio buttons <input type="radio">
input/submit - renders a submit button <button type="submit">
input/button - renders a button <button></button>
input/file - renders a file input <input type="file">
input/select - renders a select input <select></select>
input/hidden - renders a hidden input <input type="hidden">
input/password - renders a password input <input type="password">
input/number - renders a number input <input type="number">
input/date - renders a jQuery datepicker

Elgg offers some helper input types

input/access - renders an Elgg access level select
input/tags - renders an Elgg tags input
input/autocomplete - renders an Elgg entity autocomplete
input/captcha - placeholder view for plugins to extend
input/friendspicker - renders an Elgg friend autocomplete
input/userpicker - renders an Elgg user autocomplete
input/location renders an Elgg location input

Files and images ¶

Use the input/file view in your form’s content view.

// /mod/example/views/default/forms/example.php
echo elgg_view('input/file', ['name' => 'icon']);

If you wish to upload an icon for entity you can use the helper view entity/edit/icon. This view shows a file input for uploading a new icon for the entity, an thumbnail of the current icon and the option to remove the current icon.

The view supports some variables to control the output

entity - the entity to add/remove the icon for. If provided based on this entity the thumbnail and remove option wil be shown
entity_type - the entity type for which the icon will be uploaded. Plugins could find this usefull, maybe to validate icon sizes
entity_subtype - the entity subtype for which the icon will be uploaded. Plugins could find this usefull, maybe to validate icon sizes
icon_type - the type of the icon (default: icon)
name - name of the input/file (default: icon)
remove_name - name of the remove icon toggle (default: $vars[‚name‘] . ‚_remove‘)
required - is icon upload required (default: false)
show_remove - show the remove icon option (default: true)
show_thumb - show the thumb of the entity if available (default: true)
thumb_size - the icon size to use as the thumb (default: medium)

If using the helper view you can use the following code in you action to save the icon to the entity or remove the current icon.

if (get_input('icon_remove')) {
   $entity->deleteIcon();
} else {
   $entity->saveIconFromUploadedFile('icon');
}

Set the enctype of the form to multipart/form-data:

echo elgg_view_form('example', array(
  'enctype' => 'multipart/form-data'
));

Bemerkung

The enctype of all forms that use the method POST defaults to multipart/form-data.

In your action file, use elgg_get_uploaded_file('your-input-name') to access the uploaded file:

$icon = elgg_get_uploaded_file('icon');

Sticky forms ¶

Sticky forms are forms that retain user input if saving fails. They are „sticky“ because the user’s data „sticks“ in the form after submitting, though it was never saved to the database. This greatly improves the user experience by minimizing data loss. Elgg includes helper functions so you can make any form sticky.

Helper functions ¶

Sticky forms are implemented in Elgg by the following functions:

elgg_make_sticky_form($name) - Tells the engine to make all input on a form sticky.
elgg_clear_sticky_form($name) - Tells the engine to discard all sticky input on a form.
elgg_is_sticky_form($name) - Checks if $name is a valid sticky form.
elgg_get_sticky_values($name) - Returns all sticky values saved for $name by elgg_make_sticky_form($name).

Overview ¶

The basic flow of using sticky forms is:

Call elgg_make_sticky_form($name) at the top of actions for forms you want to be sticky.
Use elgg_is_sticky_form($name) and elgg_get_sticky_values($name) to get sticky values when rendering a form view.
Call elgg_clear_sticky_form($name) after the action has completed successfully or after data has been loaded by elgg_get_sticky_values($name).

Example: User registration ¶

Simple sticky forms require little logic to determine the input values for the form. This logic is placed at the top of the form body view itself.

The registration form view first sets default values for inputs, then checks if there are sticky values. If so, it loads the sticky values before clearing the sticky form:

// views/default/forms/register.php
$password = $password2 = '';
$username = get_input('u');
$email = get_input('e');
$name = get_input('n');

if (elgg_is_sticky_form('register')) {
   extract(elgg_get_sticky_values('register'));
   elgg_clear_sticky_form('register');
}

The registration action sets creates the sticky form and clears it once the action is completed:

// actions/register.php
elgg_make_sticky_form('register');

...

$guid = register_user($username, $password, $name, $email, false, $friend_guid, $invitecode);

if ($guid) {
   elgg_clear_sticky_form('register');
   ....
}

Example: Bookmarks ¶

The bundled plugin Bookmarks‘ save form and action is an example of a complex sticky form.

The form view for the save bookmark action uses elgg_extract() to pull values from the $vars array:

// mod/bookmarks/views/default/forms/bookmarks/save.php
$title = elgg_extract('title', $vars, '');
$desc = elgg_extract('description', $vars, '');
$address = elgg_extract('address', $vars, '');
$tags = elgg_extract('tags', $vars, '');
$access_id = elgg_extract('access_id', $vars, ACCESS_DEFAULT);
$container_guid = elgg_extract('container_guid', $vars);
$guid = elgg_extract('guid', $vars, null);
$shares = elgg_extract('shares', $vars, array());

The page handler scripts prepares the form variables and calls elgg_view_form() passing the correct values:

// mod/bookmarks/pages/add.php
$vars = bookmarks_prepare_form_vars();
$content = elgg_view_form('bookmarks/save', array(), $vars);

Similarly, mod/bookmarks/pages/edit.php uses the same function, but passes the entity that is being edited as an argument:

$bookmark_guid = get_input('guid');
$bookmark = get_entity($bookmark_guid);

...

$vars = bookmarks_prepare_form_vars($bookmark);
$content = elgg_view_form('bookmarks/save', array(), $vars);

The library file defines bookmarks_prepare_form_vars(). This function accepts an ElggEntity as an argument and does 3 things:

Defines the input names and default values for form inputs.

Extracts the values from a bookmark object if it’s passed.

Extracts the values from a sticky form if it exists.

// mod/bookmarks/lib/bookmarks.php
function bookmarks_prepare_form_vars($bookmark = null) {
   // input names => defaults
   $values = array(
      'title' => get_input('title', ''), // bookmarklet support
      'address' => get_input('address', ''),
      'description' => '',
      'access_id' => ACCESS_DEFAULT,
      'tags' => '',
      'shares' => array(),
      'container_guid' => elgg_get_page_owner_guid(),
      'guid' => null,
      'entity' => $bookmark,
   );

   if ($bookmark) {
      foreach (array_keys($values) as $field) {
         if (isset($bookmark->$field)) {
            $values[$field] = $bookmark->$field;
         }
      }
   }

   if (elgg_is_sticky_form('bookmarks')) {
      $sticky_values = elgg_get_sticky_values('bookmarks');
      foreach ($sticky_values as $key => $value) {
         $values[$key] = $value;
      }
   }

   elgg_clear_sticky_form('bookmarks');

   return $values;
}

The save action checks the input, then clears the sticky form upon success:

// mod/bookmarks/actions/bookmarks/save.php
elgg_make_sticky_form('bookmarks');

...

if ($bookmark->save()) {
   elgg_clear_sticky_form('bookmarks');
}

Ajax ¶

See the Ajax guide for instructions on calling actions from JavaScript.

Security ¶

For enhanced security, all actions require an CSRF token. Calls to action URLs that do not include security tokens will be ignored and a warning will be generated.

A few views and functions automatically generate security tokens:

elgg_view('output/url', array('is_action' => true));
elgg_view('input/securitytoken');
$url = elgg_add_action_tokens_to_url("http://localhost/elgg/action/example");
$url = elgg_generate_action_url('myplugin/myaction');

In rare cases, you may need to generate tokens manually:

$__elgg_ts = time();
$__elgg_token = generate_action_token($__elgg_ts);

You can also access the tokens from javascript:

elgg.security.token.__elgg_ts;
elgg.security.token.__elgg_token;

These are refreshed periodically so should always be up-to-date.

Security Tokens ¶

On occasion we need to pass data through an untrusted party or generate an „unguessable token“ based on some data. The industry-standard HMAC algorithm is the right tool for this. It allows us to verify that received data were generated by our site, and were not tampered with. Note that even strong hash functions like SHA-2 should not be used without HMAC for these tasks.

Elgg provides elgg_build_hmac() to generate and validate HMAC message authentication codes that are unguessable without the site’s private key.

// generate a querystring such that $a and $b can't be altered
$a = 1234;
$b = "hello";
$query = http_build_query([
    'a' => $a,
    'b' => $b,
    'mac' => elgg_build_hmac([$a, $b])->getToken(),
]);
$url = "action/foo?$query";

// validate the querystring
$a = (int) get_input('a', '', false);
$b = (string) get_input('b', '', false);
$mac = get_input('mac', '', false);

if (elgg_build_hmac([$a, $b])->matchesToken($mac)) {
    // $a and $b have not been altered
}

Note: If you use a non-string as HMAC data, you must use types consistently. Consider the following:

$mac = elgg_build_hmac([123, 456])->getToken();

// type of first array element differs
elgg_build_hmac(["123", 456])->matchesToken($mac); // false

// types identical to original
elgg_build_hmac([123, 456])->matchesToken($mac); // true

Signed URLs ¶

Signed URLs offer a limited level of security for situations where action tokens are not suitable, for example when sending a confirmation link via email. URL signatures verify that the URL has been generated by your Elgg installation (using site secret) and that the URL query elements were not tampered with.

URLs a signed with an unguessable SHA-256 HMAC key. See Security Tokens for more details.

$url = elgg_http_add_url_query_element(elgg_normalize_url('confirm'), [
   'user_guid' => $user_guid,
]);

$url = elgg_http_get_signed_url($url);

notify_user($user_guid, $site->guid, 'Confirm', "Please confirm by clicking this link: $url");

Warnung

Signed URLs do not offer CSRF protection and should not be used instead of action tokens.

Ajax¶

The elgg/Ajax AMD module (introduced in Elgg 2.1) provides a set of methods for communicating with the server in a concise and uniform way, which allows plugins to collaborate on the request data, the server response, and the returned client-side data.

Client and server code written for the legacy API should not need modification.

Contents

Overview
Legacy elgg.ajax APIs

Overview ¶

All the ajax methods perform the following:

Client-side, the data option (if given as an object) is filtered by the hook ajax_request_data.
The request is made to the server, either rendering a view or a form, calling an action, or loading a path.
The method returns a jqXHR object, which can be used as a Promise.
Server-echoed content is turned into a response object (Elgg\Services\AjaxResponse) containing a string (or a JSON-parsed value).
The response object is filtered by the hook ajax_response.
The response object is used to create the HTTP response.
Client-side, the response data is filtered by the hook ajax_response_data.
The jqXHR promise is resolved and any success callbacks are called.

More notes:

All hooks have a type depending on the method and first argument. See below.
By default the elgg/spinner module is automatically used during requests.
User messages generated by system_message() and register_error() are collected and displayed on the client.
Elgg gives you a default error handler that shows a generic message if output fails.
PHP exceptions or denied resource return HTTP error codes, resulting in use of the client-side error handler.
The default HTTP method is POST for actions, otherwise GET. You can set it via options.method.
If a non-empty options.data is given, the default method is always POST.
For client caching, set options.method to "GET" and options.data.elgg_response_ttl to the max-age you want in seconds.
To save system messages for the next page load, set options.data.elgg_fetch_messages = 0. You may want to do this if you intent to redirect the user based on the response.
To stop client-side API from requiring AMD modules required server-side with elgg_require_js(), set options.data.elgg_fetch_deps = 0.
All methods accept a query string in the first argument. This is passed on to the fetch URL, but does not appear in the hook types.

Performing actions ¶

Consider this action:

// in myplugin/actions/do_math.php

elgg_ajax_gatekeeper();

$arg1 = (int)get_input('arg1');
$arg2 = (int)get_input('arg2');

// will be rendered client-side
system_message('We did it!');

echo json_encode([
    'sum' => $arg1 + $arg2,
    'product' => $arg1 * $arg2,
]);

To execute it, use ajax.action('<action_name>', options):

var Ajax = require('elgg/Ajax');
var ajax = new Ajax();

ajax.action('do_math', {
    data: {
        arg1: 1,
        arg2: 2
    },
}).done(function (output, statusText, jqXHR) {
    if (jqXHR.AjaxData.status == -1) {
        return;
    }

    alert(output.sum);
    alert(output.product);
});

Notes for actions:

All hooks have type action:<action_name>. So in this case, three hooks will be triggered:
- client-side "ajax_request_data", "action:do_math" to filter the request data (before it’s sent)
- server-side "ajax_response", "action:do_math" to filter the response (after the action runs)
- client-side "ajax_response_data", "action:do_math" to filter the response data (before the calling code receives it)
CSRF tokens are added to the request data.
The default method is POST.
An absolute action URL can be given in place of the action name.
Using forward() in an action simply sends the response. The URL given in not returned to the client.

Bemerkung

When setting data, use ajax.objectify($form) instead of $form.serialize(). Doing so allows the ajax_request_data plugin hook to fire and other plugins to alter/piggyback on the request.

Fetching data ¶

Consider this PHP script that runs at http://example.org/myplugin_time.

// in myplugin/elgg-plugin.php
return [
    'routes' => [
        'default:myplugin:time' => [
            'path' => '/myplugin_time',
            'resource' => 'myplugin/time',
        ],
    ],
];

// in myplugin/views/default/resources/myplugin/time.php
elgg_ajax_gatekeeper();

echo json_encode([
    'rfc2822' => date(DATE_RFC2822),
    'day' => date('l'),
]);

return true;

To fetch its output, use ajax.path('<url_path>', options).

var Ajax = require('elgg/Ajax');
var ajax = new Ajax();

ajax.path('myplugin_time').done(function (output, statusText, jqXHR) {
    if (jqXHR.AjaxData.status == -1) {
        return;
    }

    alert(output.rfc2822);
    alert(output.day);
});

Notes for paths:

The 3 hooks (see Actions above) will have type path:<url_path>. In this case, „path:myplugin_time“.
If the page handler echoes a regular web page, output will be a string containing the HTML.
An absolute URL can be given in place of the path name.

Fetching views ¶

Consider this view:

// in myplugin/views/default/myplugin/get_link.php

if (empty($vars['entity']) || !$vars['entity'] instanceof ElggObject) {
    return;
}

$object = $vars['entity'];
/* @var ElggObject $object */

echo elgg_view('output/url', [
    'text' => $object->getDisplayName(),
    'href' => $object->getUrl(),
    'is_trusted' => true,
]);

Since it’s a PHP file, we must register it for Ajax first:

// in myplugin_init()
elgg_register_ajax_view('myplugin/get_link');

To fetch the view, use ajax.view('<view_name>', options):

var Ajax = require('elgg/Ajax');
var ajax = new Ajax();

ajax.view('myplugin/get_link', {
    data: {
        guid: 123 // querystring
    },
}).done(function (output, statusText, jqXHR) {
    if (jqXHR.AjaxData.status == -1) {
        return;
    }

    $('.myplugin-link').html(output);
});

Notes for views:

The 3 hooks (see Actions above) will have type view:<view_name>. In this case, „view:myplugin/get_link“.
output will be a string with the rendered view.
The request data are injected into $vars in the view.
If the request data contains guid, the system sets $vars['entity'] to the corresponding entity or false if it can’t be loaded.

Warnung

In ajax views and forms, note that $vars can be populated by client input. The data is filtered like get_input(), but may not be the type you’re expecting or may have unexpected keys.

Fetching forms ¶

Consider we have a form view. We register it for Ajax:

// in myplugin_init()
elgg_register_ajax_view('forms/myplugin/add');

To fetch this using ajax.form('<action_name>', options).

var Ajax = require('elgg/Ajax');
var ajax = new Ajax();

ajax.form('myplugin/add').done(function (output, statusText, jqXHR) {
    if (jqXHR.AjaxData.status == -1) {
        return;
    }

    $('.myplugin-form-container').html(output);
});

Notes for forms:

The 3 hooks (see Actions above) will have type form:<action_name>. In this case, „form:myplugin/add“.
output will be a string with the rendered view.
The request data are injected into $vars in your form view.
If the request data contains guid, the system sets $vars['entity'] to the corresponding entity or false if it can’t be loaded.

Bemerkung

Only the request data are passed to the requested form view (i.e. as a third parameter accepted by elgg_view_form()). If you need to pass attributes or parameters of the form element rendered by the input/form view (i.e. normally passed as a second parameter to elgg_view_form()), use the server-side hook view_vars, input/form.

Warnung

In ajax views and forms, note that $vars can be populated by client input. The data is filtered like get_input(), but may not be the type you’re expecting or may have unexpected keys.

Submitting forms ¶

To submit a form using Ajax, simply pass ajax parameter with form variables:

echo elgg_view_form('login', ['ajax' => true]);

Redirects ¶

Use ajax.forward() to start a spinner and redirect the user to a new destination.

var Ajax = require('elgg/Ajax');
var ajax = new Ajax();
ajax.forward('/activity');

Piggybacking on an Ajax request ¶

The client-side ajax_request_data hook can be used to append or filter data being sent by an elgg/Ajax request.

Let’s say when the view foo is fetched, we want to also send the server some data:

// in your boot module
var Ajax = require('elgg/Ajax');
var elgg = require('elgg');

var ajax = new Ajax();

elgg.register_hook_handler(Ajax.REQUEST_DATA_HOOK, 'view:foo', function (name, type, params, data) {
    // send some data back
    data.bar = 1;
    return data;
});

This data can be read server-side via get_input('bar');.

Bemerkung

If data was given as a string (e.g. $form.serialize()), the request hooks are not triggered.

Bemerkung

The form will be objectified as FormData, and the request content type will be determined accordingly. Effectively this allows plugins to submit multipart form data without using jquery.form plugin and other iframe hacks.

Piggybacking on an Ajax response ¶

The server-side ajax_response hook can be used to append or filter response data (or metadata).

Let’s say when the view foo is fetched, we want to also send the client some additional data:

use Elgg\Services\AjaxResponse;

function myplugin_append_ajax($hook, $type, AjaxResponse $response, $params) {

    // alter the value being returned
    $response->getData()->value .= " hello";

    // send some metadata back. Only client-side "ajax_response" hooks can see this!
    $response->getData()->myplugin_alert = 'Listen to me!';

    return $response;
}

// in myplugin_init()
elgg_register_plugin_hook_handler(AjaxResponse::RESPONSE_HOOK, 'view:foo', 'myplugin_append_ajax');

To capture the metadata send back to the client, we use the client-side ajax_response hook:

// in your boot module
var Ajax = require('elgg/Ajax');
var elgg = require('elgg');

elgg.register_hook_handler(Ajax.RESPONSE_DATA_HOOK, 'view:foo', function (name, type, params, data) {

    // the return value is data.value

    // the rest is metadata

    alert(data.myplugin_alert);

    return data;
});

Bemerkung

Only data.value is returned to the success function or available via the Deferred interface.

Bemerkung

Elgg uses these same hooks to deliver system messages over elgg/Ajax responses.

Handling errors ¶

Responses basically fall into three categories:

HTTP success (200) with status 0. No register_error() calls were made on the server.
HTTP success (200) with status -1. register_error() was called.
HTTP error (4xx/5xx). E.g. calling an action with stale tokens, or a server exception. In this case the done and success callbacks are not called.

You may need only worry about the 2nd case. We can do this by looking at jqXHR.AjaxData.status:

ajax.action('entity/delete?guid=123').done(function (value, statusText, jqXHR) {
    if (jqXHR.AjaxData.status == -1) {
        // a server error was already displayed
        return;
    }

    // remove element from the page
});

Requiring AMD modules ¶

Each response from an Ajax service will contain a list of AMD modules required server side with elgg_require_js(). When response data is unwrapped, these modules will be loaded asynchronously - plugins should not expect these modules to be loaded in their $.done() and $.then() handlers and must use require() for any modules they depend on. Additionally AMD modules should not expect the DOM to have been altered by an Ajax request when they are loaded - DOM events should be delegated and manipulations on DOM elements should be delayed until all Ajax requests have been resolved.

Legacy elgg.ajax APIs ¶

Elgg 1.8 introduced elgg.action, elgg.get, elgg.getJSON, and other methods which behave less consistently both client-side and server-side.

Legacy elgg.action ¶

Differences:

you must manually pull the output from the returned wrapper
the success handler will fire even if the action is prevented
the success handler will receive a wrapper object. You must look for wrapper.output
no ajax hooks

elgg.action('do_math', {
    data: {
        arg1: 1,
        arg2: 2
    },
    success: function (wrapper) {
        if (wrapper.output) {
            alert(wrapper.output.sum);
            alert(wrapper.output.product);
        } else {
            // the system prevented the action from running, but we really don't
            // know why
            elgg.ajax.handleAjaxError();
        }
    }
});

elgg.action notes¶

It’s best to echo a non-empty string, as this is easy to validate in the success function. If the action was not allowed to run for some reason, wrapper.output will be an empty string.

You may want to use the elgg/spinner module.

Elgg does not use wrapper.status for anything, but a call to register_error() causes it to be set to -1.

If the action echoes a non-JSON string, wrapper.output will contain that string.

elgg.action is based on jQuery.ajax and returns a jqXHR object (like a Promise), if you should want to use it.

After the PHP action completes, other plugins can alter the wrapper via the plugin hook 'output', 'ajax', which filters the wrapper as an array (not a JSON string).

A forward() call forces the action to be processed and output immediately, with the wrapper.forward_url value set to the normalized location given.

To make sure Ajax actions can only be executed via XHR, use elgg_ajax_gatekeeper().

elgg.action JSON response wrapper¶

Warnung

It’s probably best to rely only on the output key, and validate it in case the PHP action could not run for some reason, e.g. the user was logged out or a CSRF attack did not provide tokens.

Warnung

If forward() is used in response to a legacy ajax request (e.g. elgg.ajax), Elgg will always respond with this wrapper, even if not in an action.

Legacy view fetching ¶

A plugin can use a view script to handle XHR GET requests. Here’s a simple example of a view that returns a link to an object given by its GUID:

// in myplugin_init()
elgg_register_ajax_view('myplugin/get_link');

// in myplugin/views/default/myplugin/get_link.php

if (empty($vars['entity']) || !$vars['entity'] instanceof ElggObject) {
    return;
}

$object = $vars['entity'];
/* @var ElggObject $object */

echo elgg_view('output/url', [
    'text' => $object->getDisplayName(),
    'href' => $object->getUrl(),
    'is_trusted' => true,
]);

elgg.get('ajax/view/myplugin/get_link', {
    data: {
        guid: 123 // querystring
    },
    success: function (output) {
        $('.myplugin-link').html(output);
    }
});

The Ajax view system works significantly differently than the action system.

There are no access controls based on session status.

Non-XHR requests are automatically rejected.

GET vars are injected into $vars in the view.

If the request contains $_GET['guid'], the system sets $vars['entity'] to the corresponding entity or false if it can’t be loaded.

There’s no „wrapper“ object placed around the view output.

System messages/errors shouldn’t be used, as they don’t display until the user loads another page.

Depending on the view’s suffix (.js, .html, .css, etc.), a corresponding Content-Type header is added.

Warnung

In ajax views and forms, note that $vars can be populated by client input. The data is filtered like: get_input(), but may not be the type you’re expecting or may have unexpected keys.

Returning JSON from a view¶

If the view outputs encoded JSON, you must use elgg.getJSON to fetch it (or use some other method to set jQuery’s ajax option dataType to json). Your success function will be passed the decoded Object.

Here’s an example of fetching a view that returns a JSON-encoded array of times:

elgg.getJSON('ajax/view/myplugin/get_times', {
    success: function (data) {
        alert('The time is ' + data.friendly_time);
    }
});

Legacy form fetching ¶

If you register a form view (name starting with forms/), you can fetch it pre-rendered with elgg_view_form(). Simply use ajax/form/<action> (instead of ajax/view/<view_name>):

// in myplugin_init()
elgg_register_ajax_view('forms/myplugin/add');

elgg.get('ajax/form/myplugin/add', {
    success: function (output) {
        $('.myplugin-form-container').html(output);
    }
});

Only the request data are passed to the requested form view (i.e. as a third parameter accepted by elgg_view_form()). If you need to pass attributes or parameters of the form element rendered by the input/form view (i.e. normally passed as a second parameter to elgg_view_form()), use the server-side hook view_vars, input/form.

Warnung

In ajax views and forms, note that $vars can be populated by client input. The data is filtered like: get_input(), but may not be the type you’re expecting or may have unexpected keys.

Legacy helper functions ¶

These functions extend jQuery’s native Ajax features.

elgg.get() is a wrapper for jQuery’s $.ajax(), but forces GET and does URL normalization.

// normalizes the url to the current <site_url>/activity
elgg.get('/activity', {
    success: function(resultText, success, xhr) {
        console.log(resultText);
    }
});

elgg.post() is a wrapper for jQuery’s $.ajax(), but forces POST and does URL normalization.

Authentication¶

Elgg provides everything needed to authenticate users via username/email and password out of the box, including:

remember-me cookies for persistent login

password reset logic

secure storage of passwords

logout

UIs for accomplishing all of the above

All that’s left for you to do as a developer is to use the built-in authentication functions to secure your pages and actions.

Working with the logged in user¶

Check whether the current user is logged in with elgg_is_logged_in():

if (elgg_is_logged_in()) {
  // do something just for logged-in users
}

Check if the current user is an admin with elgg_is_admin_logged_in():

if (elgg_is_admin_logged_in()) {
  // do something just for admins
}

Get the currently logged in user with elgg_get_logged_in_user_entity():

$user = elgg_get_logged_in_user_entity();

The returned object is an ElggUser so you can use all the methods and properties of that class to access information about the user. If the user is not logged in, this will return null, so be sure to check for that first.

Gatekeepers¶

Gatekeeper functions allow you to manage how code gets executed by applying access control rules.

Forward a user to the front page if they are not logged in with elgg_gatekeeper():

elgg_gatekeeper();

echo "Information for logged-in users only";

Forward a user to the front page unless they are an admin with elgg_admin_gatekeeper():

elgg_admin_gatekeeper();

echo "Information for admins only";

Pluggable Authentication Modules¶

Elgg has support for pluggable authentication modules (PAM), which enables you to write your own authentication handlers. Whenever a request needs to get authenticated the system will call elgg_authenticate() which probes the registered PAM handlers until one returns success.

The preferred approach is to create a separate Elgg plugin which will have one simple task: to process an authentication request. This involves setting up an authentication handler in the plugin’s start.php file, and to register it with the PAM module so it will get processed whenever the system needs to authenticate a request.

The authentication handler is a function and takes a single parameter. Registering the handler is being done by register_pam_handler() which takes the name of the authentication handler, the importance and the policy as parameters. It is advised to register the handler in the plugin’s init function, for example:

function your_plugin_init() {
   // Register the authentication handler
   register_pam_handler('your_plugin_auth_handler');
}

function your_plugin_auth_handler($credentials) {
   // do things ...
}

// Add the plugin's init function to the system's init event
elgg_register_elgg_event_handler('init', 'system', 'your_plugin_init');

Importance¶

By default an authentication module is registered with an importance of sufficient.

In a list of authentication modules; if any one marked sufficient returns true, pam_authenticate() will also return true. The exception to this is when an authentication module is registered with an importance of required. All required modules must return true for pam_authenticate() to return true, regardless of whether all sufficient modules return true.

Passed credentials¶

The format of the credentials passed to the handler can vary, depending on the originating request. For example, a regular login via the login form will create a named array, with the keys username and password. If a request was made for example via XML-RPC then the credentials will be set in the HTTP header, so in this case nothing will get passed to the authentication handler and the handler will need to perform steps on its own to authenticate the request.

Return value¶

The authentication handle should return a boolean, indicating if the request could be authenticated or not. One caveat is that in case of a regular user login where credentials are available as username and password the user will get logged in. In case of the XML-RPC example the authentication handler will need to perform this step itself since the rest of the system will not have any idea of either possible formats of credentials passed nor its contents. Logging in a user is quite simple and is being done by login(), which expects an ElggUser object.

Context¶

Warnung

The contents of this page are outdated. While the functionality is still in place, using global context to determine your business logic is bad practice, and will make your code less testable and succeptive to bugs.

Within the Elgg framework, context can be used by your plugin’s functions to determine if they should run or not. You will be registering callbacks to be executed when particular events are triggered. Sometimes the events are generic and you only want to run your callback when your plugin caused the event to be triggered. In that case, you can use the page’s context.

You can explicitly set the context with set_context(). The context is a string and typically you set it to the name of your plugin. You can retrieve the context with the function get_context(). It’s however better to use elgg_push_context($string) to add a context to the stack. You can check if the context you want in in the current stack by calling elgg_in_context($context). Don’t forget to pop (with elgg_pop_context()) the context after you push one and don’t need it anymore.

If you don’t set it, Elgg tries to guess the context. If the page was called through the router, the context is set to the first segment of the current route, e.g. profile in profile/username.

Sometimes a view will return different HTML depending on the context. A plugin can take advantage of that by setting the context before calling elgg_view() on the view and then setting the context back. This is frequently done with the search context.

Cron¶

If you setup cron correctly as described in Cron special hooks will be triggered so you can register for these hooks from your own code.

The example below registers a function for the daily cron.

function my_plugin_init() {
    elgg_register_plugin_hook_handler('cron', 'daily', 'my_plugin_cron_handler');
}

If timing is important in your cron hook be advised that the functions are executed in order of registration. This could mean that your function may start (a lot) later then you may have expected. However the parameters provided in the hook contain the original starting time of the cron, so you can always use that information.

function my_plugin_cron_handler(\Elgg\Hook $hook) {
    $start_time = $hook->getParam('time');
}

Custom intervals¶

Plugin developers can configure there own custom intervals.

Warnung

It’s NOT recommended to do this, as the users of your plugin may also need to configure your custom interval. Try to work with the default intervals. If you only need to do a certain task at for example 16:30 you can use the halfhour interval and check that date('G', $start_time) == 16 and date('i', $start_time) == 30

elgg_register_plugin_hook_hander('cron:intervals', 'system', 'my_custom_cron_interval');

function my_custom_cron_interval(\Elgg\Hook $hook) {
        $cron_intervals = $hook->getValue();

        // add custom interval
        $cron_intervals['my_custom_interval'] = '30 16 * * *'; // every day at 16:30 hours

        return $cron_intervals;
}

Siehe auch

Events and Plugin Hooks has more information about hooks
For more information about the supported cron interval definition see the PHP Scheduler documentation

Database¶

Persist user-generated content and settings with Elgg’s generic storage API.

Contents

Entities
Custom database functionality
- Example: Run SQL script on plugin activation
Systemlog
- System log storage
- Creating your own system log

Entities ¶

Creating an object ¶

To create an object in your code, you need to instantiate an ElggObject. Setting data is simply a matter of adding instance variables or properties. The built-in properties are:

``guid`` The entity’s GUID; set automatically
``owner_guid`` The owning user’s GUID
``subtype`` A single-word arbitrary string that defines what kind of object it is, for example blog
``access_id`` An integer representing the access level of the object
``title`` The title of the object
``description`` The description of the object

The object subtype is a special property. This is an arbitrary string that describes what the object is. For example, if you were writing a blog plugin, your subtype string might be blog. It’s a good idea to make this unique, so that other plugins don’t accidentally try and use the same subtype. For the purposes of this document, let’s assume we’re building a simple forum. Therefore, the subtype will be forum:

$object = new ElggObject();
$object->subtype = "forum";
$object->access_id = 2;
$object->save();

access_id is another important property. If you don’t set this, your object will be private, and only the creator user will be able to see it. Elgg defines constants for the special values of access_id:

ACCESS_PRIVATE Only the owner can see it
ACCESS_LOGGED_IN Any logged in user can see it
ACCESS_PUBLIC Even visitors not logged in can see it

Saving the object will automatically populate the $object->guid property if successful. If you change any more base properties, you can call $object->save() again, and it will update the database for you.

You can set metadata on an object just like a standard property. Let’s say we want to set the SKU of a product:

$object->SKU = 62784;

If you assign an array, all the values will be set for that metadata. This is how, for example, you set tags.

Metadata cannot be persisted to the database until the entity has been saved, but for convenience, ElggEntity can cache it internally and save it when saving the entity.

Loading an object ¶

By GUID¶

$entity = get_entity($guid);
if (!$entity) {
    // The entity does not exist or you're not allowed to access it.
}

But what if you don’t know the GUID? There are several options.

By user, subtype or site¶

If you know the user ID you want to get objects for, or the subtype, you have several options. The easiest is probably to call the procedural function elgg_get_entities:

$entities = elgg_get_entities(array(
    'type' => $entity_type,
    'subtype' => $subtype,
    'owner_guid' => $owner_guid,
));

This will return an array of ElggEntity objects that you can iterate through. elgg_get_entities paginates by default, with a limit of 10; and offset 0.

You can leave out owner_guid to get all objects and leave out subtype or type to get objects of all types/subtypes.

If you already have an ElggUser – e.g. elgg_get_logged_in_user_entity, which always has the current user’s object when you’re logged in – you can simply use:

$objects = $user->getObjects($subtype, $limit, $offset)

But what about getting objects with a particular piece of metadata?

By properties¶

You can fetch entities by their properties using elgg_get_entities. Using specific parameters passed to $options array, you can retrieve entities by their attributes, metadata, annotations, private settings and relationships.

Displaying entities ¶

In order for entities to be displayed in listing functions you need to provide a view for the entity in the views system.

To display an entity, create a view EntityType/subtype where EntityType is one of the following:

object: for entities derived from ElggObject user: for entities derived from ElggUser site: for entities derived from ElggSite group: for entities derived from ElggGroup

A default view for all entities has already been created, this is called EntityType/default.

Entity Icons¶

Entity icons can be saved from uploaded files, existing local files, or existing ElggFile objects. These methods save the master size of the icon defined in the system. The other defined sizes will be generated when requested.

$object = new ElggObject();
$object->title = 'Example entity';
$object->description = 'An example object with an icon.';

// from an uploaded file
$object->saveIconFromUploadedFile('file_upload_input');

// from a local file
$object->saveIconFromLocalFile('/var/data/generic_icon.png');

// from a saved ElggFile object
$file = get_entity(123);
if ($file instanceof ElggFile) {
        $object->saveIconFromElggFile($file);
}

$object->save();

The following sizes exist by default:

master - 10240px at longer edge (not upscaled)
large - 200px at longer edge (not upscaled)
medium - 100px square
small - 40px square
tiny - 25px square
topbar - 16px square

Use elgg_get_icon_sizes() to get all possible icon sizes for a specific entity type and subtype. The function triggers the entity:icon:sizes hook.

To check if an icon is set, use $object->hasIcon($size).

You can retrieve the URL of the generated icon with ElggEntity::getIconURL($params) method. This method accepts a $params argument as an array that specifies the size, type, and provide additional context for the hook to determine the icon to serve. The method triggers the entity:icon:url hook.

Use elgg_view_entity_icon($entity, $size, $vars) to render an icon. This will scan the following locations for a view and include the first match to .

views/$viewtype/icon/$type/$subtype.php
views/$viewtype/icon/$type/default.php
views/$viewtype/icon/default.php

Where

$viewtype: Type of view, e.g. 'default' or 'json'.
$type: Type of entity, e.g. 'group' or 'user'.
$subtype: Entity subtype, e.g. 'blog' or 'page'.

You do not have to return a fallback icon from the hook handler. If no uploaded icon is found, the view system will scan the views (in this specific order):

views/$viewtype/$icon_type/$entity_type/$entity_subtype.svg
views/$viewtype/$icon_type/$entity_type/$entity_subtype/$size.gif
views/$viewtype/$icon_type/$entity_type/$entity_subtype/$size.png
views/$viewtype/$icon_type/$entity_type/$entity_subtype/$size.jpg

Where

$viewtype: Type of view, e.g. 'default' or 'json'.
$icon_type: Icon type, e.g. 'icon' or 'cover_image'.
$entity_type: Type of entity, e.g. 'group' or 'user'.
$entity_subtype: Entity subtype, e.g. 'blog' or 'page' (or 'default' if entity has not subtype).
$size: Icon size (note that we do not use the size with svg icons)

Icon methods support passing an icon type if an entity has more than one icon. For example, a user might have an avatar and a cover photo icon. You would pass 'cover_photo' as the icon type:

$object->saveIconFromUploadedFile('uploaded_photo', 'cover_photo');

$object->getIconUrl([
        'size' => 'medium',
        'type' => 'cover_photo'
]);

Bemerkung

Custom icon types (e.g. cover photos) only have a preset for master size, to add custom sizes use entity:<icon_type>:url hook to configure them.

By default icons will be stored in /icons/<icon_type>/<size>.jpg relative to entity’s directory on filestore. To provide an alternative location, use the entity:<icon_type>:file hook.

Adding, reading and deleting annotations ¶

Annotations could be used, for example, to track ratings. To annotate an entity you can use the object’s annotate() method. For example, to give a blog post a rating of 5, you could use:

$blog_post->annotate('rating', 5);

To retrieve the ratings on the blog post, use $blogpost->getAnnotations('rating') and if you want to delete an annotation, you can operate on the ElggAnnotation class, eg $annotation->delete().

Retrieving a single annotation can be done with get_annotation() if you have the annotation’s ID. If you delete an ElggEntity of any kind, all its metadata, annotations, and relationships will be automatically deleted as well.

Extending ElggEntity ¶

If you derive from one of the Elgg core classes, you’ll need to tell Elgg how to properly instantiate the new type of object so that get_entity() et al. will return the appropriate PHP class. For example, if I customize ElggGroup in a class called „Committee“, I need to make Elgg aware of the new mapping. Following is an example class extension:

// Class source
class Committee extends ElggGroup {

    protected function initializeAttributes() {
        parent::initializeAttributes();
        $this->attributes['subtype'] = 'committee';
    }

    // more customizations here
}

In your plugins elgg-plugin.php file add the entities section.

<?php // mod/example/elgg-plugin.php
return [
    // entities registration
    'entities' => [
                    [
                            'type' => 'group',
                            'subtype' => 'committee',
                            'class' => 'Committee',
                            'searchable' => true,
                    ],
            ],
];

The entities will be registered upon activation of the plugin.

Now if you invoke get_entity() with the GUID of a committee object, you’ll get back an object of type Committee.

Advanced features ¶

Entity URLs¶

Entity urls are provided by the getURL() interface and provide the Elgg framework with a common way of directing users to the appropriate display handler for any given object.

For example, a profile page in the case of users.

The url is set using the elgg\_register\_entity\_url\_handler() function. The function you register must return the appropriate url for the given type - this itself can be an address set up by a page handler.

The default handler is to use the default export interface.

Entity loading performance¶

elgg_get_entities has a couple options that can sometimes be useful to improve performance.

preload_owners: If the entities fetched will be displayed in a list with the owner information, you can set this option to true to efficiently load the owner users of the fetched entities.
preload_containers: If the entities fetched will be displayed in a list using info from their containers, you can set this option to true to efficiently load them.
distinct: When Elgg fetches entities using an SQL query, Elgg must be sure that each entity row appears only once in the result set. By default it includes a DISTINCT modifier on the GUID column to enforce this, but some queries naturally return unique entities. Setting the distinct option to false will remove this modifier, and rely on the query to enforce its own uniqueness.

The internals of Elgg entity queries is a complex subject and it’s recommended to seek help on the Elgg Community site before using the distinct option.

Custom database functionality ¶

It is strongly recommended to use entities wherever possible. However, Elgg supports custom SQL queries using the database API.

Example: Run SQL script on plugin activation ¶

This example shows how you can populate your database on plugin activation.

if (!elgg_get_plugin_setting('database_version', 'my_plugin') {
    run_sql_script(__DIR__ . '/sql/activate.sql');
    elgg_set_plugin_setting('database_version', 1, 'my_plugin');
}

my_plugin/sql/activate.sql:

-- Create some table
CREATE TABLE prefix_custom_table(
    id INTEGER AUTO_INCREMENT,
    name VARCHAR(32),
    description VARCHAR(32),
    PRIMARY KEY (id)
);

-- Insert initial values for table
INSERT INTO prefix_custom_table (name, description)
VALUES ('Peter', 'Some guy'), ('Lisa', 'Some girl');

Note that Elgg execute statements through PHPs built-in functions and have limited support for comments. I.e. only single line comments are supported and must be prefixed by „– “ or „# „. A comment must start at the very beginning of a line.

Systemlog ¶

Bemerkung

This section need some attention and will contain outdated information

The default Elgg system log is a simple way of recording what happens within an Elgg system. It’s viewable and searchable directly from the administration panel.

System log storage ¶

A system log row is stored whenever an event concerning an object whose class implements the Loggable interface is triggered. ElggEntity and ElggExtender implement Loggable, so a system log row is created whenever an event is performed on all objects, users, groups, sites, metadata and annotations.

Common events include:

create
update
delete
login

Creating your own system log ¶

There are some reasons why you might want to create your own system log. For example, you might need to store a full copy of entities when they are updated or deleted, for auditing purposes. You might also need to notify an administrator when certain types of events occur.

To do this, you can create a function that listens to all events for all types of object:

register_elgg_event_handler('all','all','your_function_name');

Your function can then be defined as:

function your_function_name($object, $event) {
   if ($object instanceof Loggable) {
      ...
   }
}

You can then use the extra methods defined by Loggable to extract the information you need.

Error Handling¶

Under the hood, Elgg uses Monolog for logging errors to the server’s error log (and stdout for CLI commands).

Monolog comes with a number of tools that can help administrators keep track of errors and debugging information.

You can add custom handlers (see Monolog documentation for a full list of handlers):

// Add a new handler to notify a given email about a critical error
elgg()->logger->pushHandler(
        new \Monolog\Handler\NativeMailerHandler(
                'admin@example.com',
                'Critical error',
                'no-reply@mysite.com',
                \Monolog\Logger::CRITICAL
        )
);

List of events in core¶

For more information on how events work visit Events and Plugin Hooks.

Contents

System events
User events
Relationship events
Entity events
Metadata events
Annotation events
River events
File events
Notes

System events ¶

plugins_boot, system: Triggered just after the plugins are loaded. Rarely used. init, system is used instead.
init, system: Plugins tend to use this event for initialization (extending views, registering callbacks, etc.)
ready, system: Triggered after the init, system event. All plugins are fully loaded and the engine is ready to serve pages.
shutdown, system: Triggered after the page has been sent to the user. Expensive operations could be done here and not make the user wait.

Bemerkung

Depending upon your server configuration the PHP output might not be shown until after the process is completed. This means that any long-running processes will still delay the page load.

Bemerkung

This event is prefered above using register_shutdown_function as you may not have access to all the Elgg services (eg. database) in the shutdown function but you will in the event.

Bemerkung

The Elgg session is already closed before this event. Manipulating session is not possible.

regenerate_site_secret:before, system: Return false to cancel regenerating the site secret. You should also provide a message to the user.
regenerate_site_secret:after, system: Triggered after the site secret has been regenerated.
log, systemlog: Called for all triggered events by system_log plugin. Used internally by system_log_default_logger() to populate the system_log table.
upgrade, system: Triggered after a system upgrade has finished. All upgrade scripts have run, but the caches are not cleared.
upgrade:execute, system: Triggered as a sequence (so including :before and :after) when executing an ElggUpgrade. The $object of the event is the ElggUpgrade.
activate, plugin: Return false to prevent activation of the plugin.
deactivate, plugin: Return false to prevent deactivation of the plugin.
init:cookie, <name>: Return false to override setting a cookie.
cache:flush, system: Reset internal and external caches, by default including system_cache, simplecache, and memcache. One might use it to reset others such as APC, OPCache, or WinCache.
send:before, http_response: Triggered before an HTTP response is sent. Handlers will receive an instance of SymfonyComponentHttpFoundationResponse that is to be sent to the requester. Handlers can terminate the event and prevent the response from being sent by returning false.
send:after, http_response: Triggered after an HTTP response is sent. Handlers will receive an instance of SymfonyComponentHttpFoundationResponse that was sent to the requester.
reload:after, translations: Triggered after the translations are (re)loaded.

User events ¶

login:before, user: Triggered during login. Returning false prevents the user from logging
login:after, user: Triggered after the user logs in.
logout:before, user: Triggered during logout. Returning false should prevent the user from logging out.
logout:after, user: Triggered after the user logouts.
validate, user: When a user registers, the user’s account is disabled. This event is triggered to allow a plugin to determine how the user should be validated (for example, through an email with a validation link).
validate:after, user: Triggered when user’s account has been validated.
invalidate:after, user: Triggered when user’s account validation has been revoked.
profileupdate, user: User has changed profile
profileiconupdate, user: User has changed profile icon
ban, user: Triggered before a user is banned. Return false to prevent.
unban, user: Triggered before a user is unbanned. Return false to prevent.
make_admin, user: Triggered before a user is promoted to an admin. Return false to prevent.
remove_admin, user: Triggered before a user is demoted from an admin. Return false to prevent.

Relationship events ¶

create, relationship: Triggered after a relationship has been created. Returning false deletes the relationship that was just created.
delete, relationship: Triggered before a relationship is deleted. Return false to prevent it from being deleted.
join, group: Triggered after the user $params['user'] has joined the group $params['group'].
leave, group: Triggered before the user $params['user'] has left the group $params['group'].

Entity events ¶

create, <entity type>: Triggered for user, group, object, and site entities after creation. Return false to delete entity.
update, <entity type>: Triggered before an update for the user, group, object, and site entities. Return false to prevent update. The entity method getOriginalAttributes() can be used to identify which attributes have changed since the entity was last saved.
update:after, <entity type>: Triggered after an update for the user, group, object, and site entities. The entity method getOriginalAttributes() can be used to identify which attributes have changed since the entity was last saved.
delete, <entity type>: Triggered before entity deletion. Return false to prevent deletion.
disable, <entity type>: Triggered before the entity is disabled. Return false to prevent disabling.
disable:after, <entity type>: Triggered after the entity is disabled.
enable, <entity type>: Return false to prevent enabling.
enable:after, <entity type>: Triggered after the entity is enabled.

Metadata events ¶

create, metadata: Called after the metadata has been created. Return false to delete the metadata that was just created.
update, metadata: Called after the metadata has been updated. Return false to delete the metadata.
delete, metadata: Called before metadata is deleted. Return false to prevent deletion.
enable, metadata: Called when enabling metadata. Return false to prevent enabling.
disable, metadata: Called when disabling metadata. Return false to prevent disabling.

Annotation events ¶

annotate, <entity type>: Called before the annotation has been created. Return false to prevent annotation of this entity.
create, annotation: Called after the annotation has been created. Return false to delete the annotation.
update, annotation: Called after the annotation has been updated. Return false to delete the annotation.
delete, annotation: Called before annotation is deleted. Return false to prevent deletion.
enable, annotation: Called when enabling annotations. Return false to prevent enabling.
disable, annotations: Called when disabling annotations. Return false to prevent disabling.

River events ¶

created, river: Called after a river item is created.

Bemerkung

Use the plugin hook creating, river to cancel creation (or alter options).
delete:before, river: Triggered before a river item is deleted. Returning false cancels the deletion.
delete:after, river: Triggered after a river item was deleted.

File events ¶

upload:after, file: Called after an uploaded file has been written to filestore. Receives an instance of ElggFile the uploaded file was written to. The ElggFile may or may not be an entity with a GUID.

Notes ¶

Because of bugs in the Elgg core, some events may be thrown more than once on the same action. For example, update, object is thrown twice.

File System¶

Contents

Filestore
File Objects
Temporary files

Filestore ¶

Location¶

Elgg’s filestore is located in the site’s dataroot that is configured during installation, and can be modified via site settings in Admin interface.

Directory Structure¶

The structure of the filestore is tied to file ownership by Elgg entities. Whenever the first file owned by an entity is written to the filestore, a directory corresponding to the entity GUID will be created within a parent bucket directory (buckets are bound to 5000 guids). E.g. files owned by user with guid 7777 will be located in 5000/7777/.

When files are created, filenames can contain subdirectory names (often referred to as $prefix throughout the code). For instance, avatars of the above user, can be found under 5000/7777/profile/.

File Objects ¶

Writing Files¶

To write a file to the filestore, you would use an instance of ElggFile. Even though ElggFile extends ElggObject and can be stored as an actual Elgg entity, that is not always necessary (e.g. when writing thumbs of an image).

$file = new ElggFile();
$file->owner_guid = 7777;
$file->setFilename('portfolio/files/sample.txt');
$file->open('write');
$file->write('Contents of the file');
$file->close();

// to uprade this file to an entity
$file->subtype = 'file';
$file->save();

Reading Files¶

You can read file contents using instanceof of ElggFile.

// from an Elgg entity
$file = get_entity($file_guid);
readfile($file->getFilenameOnFilestore());

// arbitrary file on the filestore
$file = new ElggFile();
$file->owner_guid = 7777;
$file->setFilename('portfolio/files/sample.txt');

// option 1
$file->open('read');
$contents = $file->grabFile();
$file->close();

// option 2
$contents = file_get_contents($file->getFilenameOnFilestore());

Serving Files¶

You can serve files from filestore using elgg_get_inline_url() and elgg_get_download_url(). Both functions accept 3 arguments:

``file`` An instance of ElggFile to be served
``use_cookie`` If set to true, validity of the URL will be limited to current session
``expires`` Expiration time of the URL

You can use use_cookie and expires arguments as means of access control. For example, users avatars in most cases have a long expiration time and do not need to be restricted by current session - this will allows browsers to cache the images and file service will send appropriate Not Modified headers on consecutive requests.

The default behaviour of use_cookie can be controlled on the admin security settings page.

For entities that are under Elgg’s access control, you may want to use cookies to ensure that access settings are respected and users do not share download URLs with somebody else.

You can also invalidated all previously generated URLs by updating file’s modified time, e.g. by using touch().

Embedding Files¶

Please note that due to their nature inline and download URLs are not suitable for embedding. Embed URLs must be permanent, whereas inline and download URLs are volatile (bound to user session and file modification time).

To embed an entity icon, use elgg_get_embed_url().

Handling File Uploads¶

In order to implement an action that saves a single file uploaded by a user, you can use the following approach:

// in your form
echo elgg_view('input/file', [
        'name' => 'upload',
        'label' => 'Select an image to upload',
        'help' => 'Only jpeg, gif and png images are supported',
]);

// in your action
$uploaded_file = elgg_get_uploaded_file('upload');
if (!$uploaded_file) {
        register_error("No file was uploaded");
        forward(REFERER);
}

$supported_mimes = [
        'image/jpeg',
        'image/png',
        'image/gif',
];

$mime_type = ElggFile::detectMimeType($uploaded_file->getPathname(), $uploaded_file->getClientMimeType());
if (!in_array($mime_type, $supported_mimes)) {
        register_error("$mime_type is not supported");
        forward(REFERER);
}

$file = new ElggFile();
$file->owner_guid = elgg_get_logged_in_user_guid();
if ($file->acceptUploadedFile($uploaded_file)) {
        $file->save();
}

If your file input supports multiple files, you can iterate through them in your action:

// in your form
echo elgg_view('input/file', [
        'name' => 'upload[]',
        'multiple' => true,
        'label' => 'Select images to upload',
]);

// in your action
foreach (elgg_get_uploaded_files('upload') as $upload) {
        $file = new ElggFile();
        $file->owner_guid = elgg_get_logged_in_user_guid();
        if ($file->acceptUploadedFile($upload)) {
                $file->save();
        }
}

Bemerkung

If images are uploaded their is an automatic attempt to fix the orientation of the image.

Temporary files ¶

If you ever need a temporary file you can use elgg_get_temp_file(). You’ll get an instance of an ElggTempFile which has all the file functions of an ElggFile, but writes it’s data to the systems temp folder.

Warnung

It’s not possible to save the ElggTempFile to the database. You’ll get an IOException if you try.

Group Tools¶

Elgg groups allow group administrators to enable/disable various tools available within a group. These tools are provided by other plugins like blog or file.

Plugins can access group tool register via elgg()->group_tools.

elgg()->group_tools->register('my-tool', [
        'default_on' => false, // default is true
        'label' => elgg_echo('my-tool:checkbox:label'),
        'priority' => 300, // display this earlier than other modules/tools
]);

A registered tool will have an option to be toggled on the group edit form, and can have a profile view module associated with it. To add a profile module, simply add a corresponding view as groups/profile/module/<tool_name>. This view will only be called if the tool is enabled.

If you simply wish to list some content in the group you can use the groups/profile/module view with some additional parameters.

entity_type: in combination with the entity_subtype it can generate everything the module needs

entity_subtype: in combination with the entity_type it can generate everything the module needs

no_results: custom no results found text

The following will be automaticly generated:

title: based on the the language key collection:<entity_type>:<entity_subtype>:group

content: elgg_list_entities() based on given type/subtype

all_link: based on the route name collection:<entity_type>:<entity_subtype>:group

add_link: based on the route name add:<entity_type>:<entity_subtype>:group and with a permissions check to the given type/subtype

// file: groups/profile/module/my-tool.php

// if you wish to list some content (eg. files) in the group
// you can use the following
$params = [
        'entity_type' => 'object',
        'entity_subtype' => 'file',
        'no_results' => elgg_echo('file:none'),
];
$params = $params + $vars;

echo elgg_view('groups/profile/module', $params);

Alternatively you can generate your own title and content

// file: groups/profile/module/my-tool.php

echo elgg_view('groups/profile/module', [
        'title' => elgg_echo('my-tool'),
        'content' => 'Hello, world!',
]);

You can programmically enable and disable tools for a given group:

$group = get_entity($group_guid);

// enables the file tool for the group
$group->enableTool('file');

// disables the file tool for the group
$group->disableTool('file');

If you want to allow a certain feature in a group only if the group tool option is enabled, you can check this using \ElggGroup::isToolEnabled($tool_option).

It is also a possibility to use a gatekeeper function to prevent access to a group page based on an enabled tool.

elgg_group_tool_gatekeeper('file', $group);

Siehe auch

Read more about gatekeepers here: Gatekeepers

If you need the configured group tool options for a specific group you can use the elgg()->group_tools->group($group) function.

Plugin coding guidelines¶

In addition to the Elgg Coding Standards, these are guidelines for creating plugins. Core plugins are being updated to this format and all plugin authors should follow these guidelines in their own plugins.

Siehe auch

Be sure to follow the Plugin skeleton for your plugin’s layout.

Warnung

Don’t Modify Core

Contents

Use standardized routing with page handlers
Use standardized page handlers and scripts
The object/<subtype> view
Actions
Directly calling a file
Recommended

Use standardized routing with page handlers ¶

Example: Bookmarks plugin

Page handlers should accept the following standard URLs:

Purpose	URL
All	page_handler/all
User	page_handler/owner/<username>
User friends’	page_handler/friends/<username>
Single entity	page_handler/view/<guid>/<title>
Add	page_handler/add/<container_guid>
Edit	page_handler/edit/<guid>
Group list	page_handler/group/<guid>/owner

Include page handler scripts from the page handler. Almost every page handler should have a page handler script. (Example: bookmarks/all => mod/bookmarks/views/default/resources/bookmarks/all.php)
Pass arguments like entity guids to the resource view via $vars in elgg_view_resource().
Call elgg_gatekeeper() and elgg_admin_gatekeeper() in the page handler function if required.
The group URL should use views like resources/groups/*.php to render pages.
Page handlers should not contain HTML.

Use standardized page handlers and scripts ¶

Example: Bookmarks plugin
Store page functionality in mod/<plugin>/views/default/resources/<page_handler>/<page_name>.php
Use elgg_view_resource('<page_handler>/<page_name>') to render that.
Use the content page layout in page handler scripts: $content = elgg_view_layout('content', $options);
Page handler scripts should not contain HTML
Call elgg_push_breadcrumb() in the page handler scripts.
No need to worry about setting the page owner if the URLs are in the standardized format
For group content, check the container_guid by using elgg_get_page_owner_entity()

The object/<subtype> view ¶

Example: Bookmarks plugin
Make sure there are views for $vars['full_view'] == true and $vars['full_view'] == false
Check for the object in $vars['entity'] . Use elgg_instance_of() to make sure it’s the type entity you want. Return true to short circuit the view if the entity is missing or wrong.
Use the new list body and list metadata views to help format. You should use almost no markup in these views.
Update action structure - Example: Bookmarks plugin.
Namespace action files and action names (example: mod/blog/actions/blog/save.php => action/blog/save)
Use the following action URLs:

Purpose URL

Add action/plugin/save

Edit action/plugin/save

Delete action/plugin/delete
Make the delete action accept action/<handler>/delete?guid=<guid> so the metadata entity menu has the correct URL by default

Actions ¶

Actions are transient states to perform an action such as updating the database or sending a notification to a user. Used correctly, actions provide a level of access control and prevent against CSRF attacks.

Actions require action (CSRF) tokens to be submitted via GET/POST, but these are added automatically by elgg_view_form() and by using the is_action argument of the output/url view.

Action best practices¶

Action files are included within Elgg’s action system; like views, they are not regular scripts executable by users. Do not boot the Elgg core in your file and direct users to load it directly.

Because actions are time-sensitive they are not suitable for links in emails or other delayed notifications. An example of this would be invitations to join a group. The clean way to create an invitation link is to create a page handler for invitations and email that link to the user. It is then the page handler’s responsibility to create the action links for a user to join or ignore the invitation request.

Consider that actions may be submitted via XHR requests, not just links or form submissions.

Directly calling a file ¶

This is an easy one: Don’t do it. With the exception of 3rd party application integration, there is not a reason to directly call a file in mods directory.

Recommended ¶

These points are good ideas, but are not yet in the official guidelines. Following these suggestions will help to keep your plugin consistent with Elgg core.

Update the widget views (see the blog or file widgets)
Update the group profile “widget” using blog or file plugins as example
Update the forms
- Move form bodies to /forms/<handler>/<action> to use Evan’s new elgg_view_form()
- Use input views in form bodies rather than html
- Add a function that prepares the form (see mod/file/lib/file.php for example)
- Integrate sticky forms (see the file plugin’s upload action and form prepare function)
Clean up CSS/HTML
- Should be able to remove almost all CSS (look for patterns that can be moved into core if you need CSS)
Use hyphens rather than underscores in classes/ids
Do not use the bundled category with your plugins. That is for plugins distributed with Elgg
Don’t use register_shutdown_function as you may not have access to certain Elgg parts anymore (eg database). Instead use the shutdown system event

Helper functions¶

Contents

Input and output
Entity methods
Entity and context retrieval
Plugins
Interface and annotations
Messages
E-mail address formatting

Input and output ¶

get_input($name) Grabs information from a form field (or any variable passed using GET or POST). Also sanitises input, stripping Javascript etc.
set_input($name, $value) Forces a value to a particular variable for subsequent retrieval by get_input()

Entity methods ¶

$entity->getURL() Returns the URL of any entity in the system
$entity->getGUID() Returns the GUID of any entity in the system
$entity->canEdit() Returns whether or not the current user can edit the entity
$entity->getOwnerEntity() Returns the ElggUser owner of a particular entity

Entity and context retrieval ¶

elgg_get_logged_in_user_entity() Returns the ElggUser for the current user
elgg_get_logged_in_user_guid() Returns the GUID of the current user
elgg_is_logged_in() Is the viewer logged in
elgg_is_admin_logged_in() Is the view an admin and logged in
elgg_gatekeeper() Shorthand for checking if a user is logged in. Forwards user to front page if not
elgg_admin_gatekeeper() Shorthand for checking the user is logged in and is an admin. Forwards user to front page if not
get_user($user_guid) Given a GUID, returns a full ElggUser entity
elgg_get_page_owner_guid() Returns the GUID of the current page owner, if there is one
elgg_get_page_owner_entity() Like elgg_get_page_owner_guid() but returns the full entity
elgg_get_context() Returns the current page’s context - eg „blog“ for the blog plugin, „thewire“ for the wire, etc. Returns „main“ as default
elgg_set_context($context) Forces the context to be a particular value
elgg_push_context($context) Adds a context to the stack
elgg_pop_context() Removes the top context from the stack
elgg_in_context($context) Checks if you’re in a context (this checks the complete stack, eg. ‚widget‘ in ‚groups‘)

Plugins ¶

elgg_is_active_plugin($plugin_id) Check if a plugin is installed and enabled

Interface and annotations ¶

elgg_view_image_block($icon, $info) Return the result in a formatted list
elgg_view_comments($entity) Returns any comments associated with the given entity
elgg_get_friendly_time($unix_timestamp) Returns a date formatted in a friendlier way - „18 minutes ago“, „2 days ago“, etc.

Messages ¶

system_message($message) Registers a success message
register_error($message) Registers an error message
elgg_view_message($type, $message) Outputs a message

E-mail address formatting ¶

Elgg has a helper class to aid in getting formatted e-mail addresses: \Elgg\Email\Address.

// the constructor takes two variables
// first is the email address, this is REQUIRED
// second is the name, this is optional
$address = new \Elgg\Email\Address('example@elgg.org', 'Example');

// this will result in 'Example <example@elgg.org>'
echo $address->toString();

// to change the name use:
$address->setName('New Example');

// to change the e-mail address use:
$address->setEmail('example2@elgg.org');

There are some helper functions available

\Elgg\Email\Address::fromString($string) Will return an \Elgg\Email\Address class with e-mail and name set, provided a formatted string (eg. Example <example@elgg.org>)
\Elgg\Email\Address::getFormattedEmailAddress($email, $name) Will return a formatted string provided an e-mail address and optionaly a name

List of plugin hooks in core ¶

For more information on how hooks work visit Events and Plugin Hooks.

Contents :local:

List of plugin hooks in core

System hooks¶

page_owner, system: Filter the page_owner for the current page. No options are passed.

siteid, system

gc, system

Allows plugins to run garbage collection for $params['period'].

unit_test, system

Add a Simple Test test. (Deprecated.)

diagnostics:report, system

Filter the output for the diagnostics report download.

cron, <period>

Triggered by cron for each period.

cron:intervals, system

Allow the configuration of custom cron intervals

validate, input

Filter GET and POST input. This is used by get_input() to sanitize user input.

prepare, html

Triggered by elgg_format_html() and used to prepare untrusted HTML.

The $return value is an array:

html - HTML string being prepared

options - Preparation options

diagnostics:report, system

Filters the output for a diagnostic report.

debug, log

Triggered by the Logger. Return false to stop the default logging method. $params includes:

level - The debug level. One of:
- Elgg_Logger::OFF
- Elgg_Logger::ERROR
- Elgg_Logger::WARNING
- Elgg_Logger::NOTICE
- Elgg_Logger::INFO
msg - The message
display - Should this message be displayed?

format, friendly:title

Formats the „friendly“ title for strings. This is used for generating URLs.

format, friendly:time

Formats the „friendly“ time for the timestamp $params['time'].

format, strip_tags

Filters a string to remove tags. The original string is passed as $params['original_string'] and an optional set of allowed tags is passed as $params['allowed_tags'].

output:before, page

In elgg_view_page(), this filters $vars before it’s passed to the page shell view (page/<page_shell>). To stop sending the X-Frame-Options header, unregister the handler _elgg_views_send_header_x_frame_options() from this hook.

output, page

In elgg_view_page(), this filters the output return value.

parameters, menu:<menu_name>

Triggered by elgg_view_menu(). Used to change menu variables (like sort order) before rendering.

The $params array will contain:

name - name of the menu

sort_by - preferring sorting parameter

other parameters passed to elgg_view_menu()

register, menu:<menu_name>

Filters the initial list of menu items pulled from configuration, before the menu has been split into sections. Triggered by elgg_view_menu() and elgg()->menus->getMenu().

The $params array will contain parameters returned by parameters, menu:<menu_name> hook.

The return value is an instance of \Elgg\Collections\Collection containing \ElggMenuItem objects.

Hook handlers can add/remove items to the collection using the collection API, as well as array access operations.

prepare, menu:<menu_name>

Filters the array of menu sections before they’re displayed. Each section is a string key mapping to an area of menu items. This is a good hook to sort, add, remove, and modify menu items. Triggered by elgg_view_menu() and elgg()->menus->prepareMenu().

The $params array will contain:

selected_item - ElggMenuItem selected in the menu, if any

The return value is an instance of \Elgg\Menu\PreparedMenu. The prepared menu is a collection of \Elgg\Menu\MenuSection, which in turn are collections of \ElggMenuItem objects.

register, menu:filter:<filter_id>

Allows plugins to modify layout filter tabs on layouts that specify <filter_id> parameter. Parameters and return values are same as in register, menu:<menu_name> hook.

filter_tabs, <context>

Filters the array of ElggMenuItem used to display the All/Mine/Friends tabs. The $params array includes:

selected: the selected menu item name

user: the logged in ElggUser or null

vars: The $vars argument passed to elgg_get_filter_tabs

creating, river

The options for elgg_create_river_item are filtered through this hook. You may alter values or return false to cancel the item creation.

simplecache:generate, <view>

Filters the view output for a /cache URL when simplecache is enabled.

cache:generate, <view>

Filters the view output for a /cache URL when simplecache is disabled. Note this will be fired for every /cache request–no Expires headers are used when simplecache is disabled.

prepare, breadcrumbs

In elgg_get_breadcrumbs(), this filters the registered breadcrumbs before returning them, allowing a plugin to alter breadcrumb strategy site-wide. $params array includes:

breadcrumbs - an array of bredcrumbs, each with title and link keys

identifier - route identifier of the current page

segments - route segments of the current page

add, river

elgg.data, site: Filters cached configuration data to pass to the client. More info
elgg.data, page: Filters uncached, page-specific configuration data to pass to the client. More info
registration_url, site: Filters site’s registration URL. Can be used by plugins to attach invitation codes, referrer codes etc. to the registration URL. $params array contains an array of query elements added to the registration URL by the invoking script. The hook must return an absolute URL to the registration page.
login_url, site: Filters site’s login URL. $params array contains an array of query elements added to the login URL by the invoking script. The hook must return an absolute URL of the login page.
commands, cli: Allows plugins to register their own commands executable via elgg-cli binary. Handlers must return an array of command class names. Commands must extend \Elgg\Cli\Command to be executable.
seeds, database: Allows plugins to register their own database seeds. Seeds populate the database with fake entities for testing purposes. Seeds must extend \Elgg\Database\Seeds\Seed class to be executable via elgg-cli database:seed.
languages, translations: Allows plugins to add/remove languages from the configurable languages in the system.
generate, password: Allows plugins to generate new random cleartext passwords.

User hooks¶

usersettings:save, user

Triggered in the aggregate action to save user settings. The hook handler must return false to prevent sticky forms from being cleared (i.e. to indicate that some of the values were not saved). Do not return true from your hook handler, as you will override other hooks‘ output, instead return null to indicate successful operation.

The $params array will contain:

user - \ElggUser, whose settings are being saved

request - \Elgg\Request to the action controller

change:email, user

Triggered before the user email is changed. Allows plugins to implement additional logic required to change email, e.g. additional email validation. The hook handler must return false to prevent the email from being changed right away.

The $params array will contain:

user - \ElggUser, whose settings are being saved

email - Email address that passes sanity checks

request - \Elgg\Request to the action controller

access:collections:write, user

Filters an array of access permissions that the user $params['user_id'] is allowed to save content with. Permissions returned are of the form (id => ‚Human Readable Name‘).

registeruser:validate:username, all

Return boolean for if the string in $params['username'] is valid for a username. Hook handler can throw \RegistrationException with an error message to be shown to the user.

registeruser:validate:password, all

Return boolean for if the string in $params['password'] is valid for a password. Hook handler can throw \RegistrationException with an error message to be shown to the user.

registeruser:validate:email, all

Return boolean for if the string in $params['email'] is valid for an email address. Hook handler can throw \RegistrationException with an error message to be shown to the user.

register, user

Triggered by the register action after the user registers. Return false to delete the user. Note the function register_user does not trigger this hook. Hook handlers can throw \RegistrationException with an error message to be displayed to the user.

The $params array will contain:

user - Newly registered user entity

All parameters sent with the request to the action (incl. password, friend_guid, invitecode etc)

login:forward, user

Filters the URL to which the user will be forwarded after login.

find_active_users, system

Return the number of active users.

status, user

Triggered by The Wire when adding a post.

username:character_blacklist, user

Filters the string of blacklisted characters used to validate username during registration. The return value should be a string consisting of the disallowed characters. The default string can be found from $params['blacklist'].

Object hooks¶

comments, <entity_type>: Triggered in elgg_view_comments(). If returning content, this overrides the page/elements/comments view.
comments:count, <entity_type>: Return the number of comments on $params['entity'].
likes:count, <entity_type>: Return the number of likes for $params['entity'].

Access hooks¶

access_collection:url, access_collection

Can be used to filter the URL of the access collection.

The $params array will contain:

access_collection - ElggAccessCollection

access_collection:name, access_collection

Can be used to filter the display name (readable access level) of the access collection.

The $params array will contain:

access_collection - ElggAccessCollection

access:collections:read, user

Filters an array of access IDs that the user $params['user_id'] can see.

Warnung

The handler needs to either not use parts of the API that use the access system (triggering the hook again) or to ignore the second call. Otherwise, an infinite loop will be created.

access:collections:write, user

Filters an array of access IDs that the user $params['user_id'] can write to. In get_write_access_array(), this hook filters the return value, so it can be used to alter the available options in the input/access view. For core plugins, the value „input_params“ has the keys „entity“ (ElggEntity|false), „entity_type“ (string), „entity_subtype“ (string), „container_guid“ (int) are provided. An empty entity value generally means the form is to create a new object.

Warnung

The handler needs to either not use parts of the API that use the access system (triggering the hook again) or to ignore the second call. Otherwise, an infinite loop will be created.

access:collections:write:subtypes, user

Returns an array of access collection subtypes to be used when retrieving access collections owned by a user as part of the get_write_access_array() function.

access:collections:addcollection, collection

Triggered after an access collection $params['collection_id'] is created.

access:collections:deletecollection, collection

Triggered before an access collection $params['collection_id'] is deleted. Return false to prevent deletion.

access:collections:add_user, collection

Triggered before adding user $params['user_id'] to collection $params['collection_id']. Return false to prevent adding.

access:collections:remove_user, collection

Triggered before removing user $params['user_id'] to collection $params['collection_id']. Return false to prevent removal.

get_sql, access

Filters SQL clauses restricting/allowing access to entities and annotations.

The hook is triggered regardless if the access is ignored. The handlers may need to check if access is ignored and return early, if appended clauses should only apply to access controlled contexts.

$return value is a nested array of ands and ors.

$params includes:

table_alias - alias of the main table used in select clause

ignore_access - whether ignored access is enabled

use_enabled_clause - whether disabled entities are shown/hidden

access_column - column in the main table containing the access collection ID value

owner_guid_column - column in the main table referencing the GUID of the owner

guid_column - column in the main table referencing the GUID of the entity

enabled_column - column in the main table referencing the enabled status of the entity

query_builder - an instance of the QueryBuilder

Action hooks¶

action, <action>

Deprecated. Use 'action:validate', <action> hook instead. Triggered before executing action scripts. Return false to abort action.

action:validate, <action>

Trigger before action script/controller is executed. This hook should be used to validate/alter user input, before proceeding with the action. The hook handler can throw an instance of \Elgg\ValidationException or return false to terminate further execution.

$params array includes:

request - instance of \Elgg\Request

action_gatekeeper:permissions:check, all

Triggered after a CSRF token is validated. Return false to prevent validation.

action_gatekeeper:upload_exceeded_msg, all

Triggered when a POST exceeds the max size allowed by the server. Return an error message to display.

forward, <reason>

Filter the URL to forward a user to when forward($url, $reason) is called. In certain cases, the params array will contain an instance of HttpException that triggered the error.

response, action:<action>

Filter an instance of \Elgg\Http\ResponseBuilder before it is sent to the client. This hook can be used to modify response content, status code, forward URL, or set additional response headers. Note that the <action> value is parsed from the request URL, therefore you may not be able to filter the responses of action() calls if they are nested within the another action script file.

Ajax¶

ajax_response, *

When the elgg/Ajax AMD module is used, this hook gives access to the response object (\Elgg\Services\AjaxResponse) so it can be altered/extended. The hook type depends on the method call:

elgg/Ajax method	plugin hook type
action()	action:<action_name>
path()	path:<url_path>
view()	view:<view_name>
form()	form:<action_name>

output, ajax

This filters the JSON output wrapper returned to the legacy ajax API (elgg.ajax, elgg.action, etc.). Plugins can alter the output, forward URL, system messages, and errors. For the elgg/Ajax AMD module, use the ajax_response hook documented above.

Permission hooks¶

container_logic_check, <entity_type>

Triggered by ElggEntity:canWriteToContainer() before triggering permissions_check and container_permissions_check hooks. Unlike permissions hooks, logic check can be used to prevent certain entity types from being contained by other entity types, e.g. discussion replies should only be contained by discussions. This hook can also be used to apply status logic, e.g. do disallow new replies for closed discussions.

The handler should return false to prevent an entity from containing another entity. The default value passed to the hook is null, so the handler can check if another hook has modified the value by checking if return value is set. Should this hook return false, container_permissions_check and permissions_check hooks will not be triggered.

The $params array will contain:

container - An entity that will be used as a container

user - User who will own the entity to be written to container

subtype - Subtype of the entity to be written to container (entity type is assumed from hook type)

container_permissions_check, <entity_type>

Return boolean for if the user $params['user'] can use the entity $params['container'] as a container for an entity of <entity_type> and subtype $params['subtype'].

In the rare case where an entity is created with neither the container_guid nor the owner_guid matching the logged in user, this hook is called twice, and in the first call $params['container'] will be the owner, not the entity’s real container.

The $params array will contain:

container - An entity that will be used as a container

user - User who will own the entity to be written to container

subtype - Subtype of the entity to be written to container (entity type is assumed from hook type)

permissions_check, <entity_type>

Return boolean for if the user $params['user'] can edit the entity $params['entity'].

permissions_check:delete, <entity_type>

Return boolean for if the user $params['user'] can delete the entity $params['entity']. Defaults to $entity->canEdit().

permissions_check:delete, river

Return boolean for if the user $params['user'] can delete the river item $params['item']. Defaults to true for admins and false for other users.

permissions_check:download, file

Return boolean for if the user $params['user'] can download the file in $params['entity'].

The $params array will contain:

entity - Instance of ElggFile

user - User who will download the file

permissions_check, widget_layout

Return boolean for if $params['user'] can edit the widgets in the context passed as $params['context'] and with a page owner of $params['page_owner'].

permissions_check:metadata, <entity_type>

(Deprecated) Return boolean for if the user $params['user'] can edit the metadata $params['metadata'] on the entity $params['entity'].

permissions_check:comment, <entity_type>

Return boolean for if the user $params['user'] can comment on the entity $params['entity'].

permissions_check:annotate:<annotation_name>, <entity_type>

Return boolean for if the user $params['user'] can create an annotation <annotation_name> on the entity $params['entity']. If logged in, the default is true.

Bemerkung

This is called before the more general permissions_check:annotate hook, and its return value is that hook’s initial value.

permissions_check:annotate, <entity_type>

Return boolean for if the user $params['user'] can create an annotation $params['annotation_name'] on the entity $params['entity']. if logged in, the default is true.

permissions_check:annotation

Return boolean for if the user in $params['user'] can edit the annotation $params['annotation'] on the entity $params['entity']. The user can be null.

fail, auth

Return the failure message if authentication failed. An array of previous PAM failure methods is passed as $params.

api_key, use

Triggered by api_auth_key(). Returning false prevents the key from being authenticated.

gatekeeper, <entity_type>:<entity_subtype>

Filters the result of elgg_entity_gatekeeper() to prevent or allow access to an entity that user would otherwise have or not have access to. A handler can return false or an instance of HttpException to prevent access to an entity. A handler can return true to override the result of the gatekeeper. Important that the entity received by this hook is fetched with ignored access and including disabled entities, so you have to be careful to not bypass the access system.

$params array includes:

entity - Entity that is being accessed

user - User accessing the entity (null implies logged in user)

Notifications¶

These hooks are listed chronologically in the lifetime of the notification event. Note that not all hooks apply to instant notifications.

enqueue, notification

Can be used to prevent a notification event from sending subscription notifications. Hook handler must return false to prevent a subscription notification event from being enqueued.

$params array includes:

object - object of the notification event

action - action that triggered the notification event. E.g. corresponds to publish when elgg_trigger_event('publish', 'object', $object) is called

get, subscriptions

Filters subscribers of the notification event. Applies to subscriptions and instant notifications. In case of a subscription event, by default, the subscribers list consists of the users subscribed to the container entity of the event object. In case of an instant notification event, the subscribers list consists of the users passed as recipients to notify_user()

IMPORTANT Always validate the notification event, object and/or action types before adding any new recipients to ensure that you do not accidentally dispatch notifications to unintended recipients. Consider a situation, where a mentions plugin sends out an instant notification to a mentioned user - any hook acting on a subject or an object without validating an event or action type (e.g. including an owner of the original wire thread) might end up sending notifications to wrong users.

$params array includes:

event - \Elgg\Notifications\NotificationEvent instance that describes the notification event

origin - subscriptions_service or instant_notifications

methods_override - delivery method preference for instant notifications

Handlers must return an array in the form:

array(
        <user guid> => array('sms'),
        <user_guid2> => array('email', 'sms', 'ajax')
);

send:before, notifications

Triggered before the notification event queue is processed. Can be used to terminate the notification event. Applies to subscriptions and instant notifications.

$params array includes:

event - \Elgg\Notifications\NotificationEvent instance that describes the notification event

subscriptions - a list of subscriptions. See 'get', 'subscriptions' hook for details

prepare, notification

A high level hook that can be used to alter an instance of \Elgg\Notifications\Notification before it is sent to the user. Applies to subscriptions and instant notifications. This hook is triggered before a more granular 'prepare', 'notification:<action>:<entity_type>:<entity_subtype>' and after 'send:before', 'notifications. Hook handler should return an altered notification object.

$params may vary based on the notification type and may include:

event - \Elgg\Notifications\NotificationEvent instance that describes the notification event

object - object of the notification event. Can be null for instant notifications

action - action that triggered the notification event. May default to notify_user for instant notifications

method - delivery method (e.g. email, site)

sender - sender

recipient - recipient

language - language of the notification (recipient’s language)

origin - subscriptions_service or instant_notifications

prepare, notification:<action>:<entity_type>:<entity_type>

A granular hook that can be used to filter a notification \Elgg\Notifications\Notification before it is sent to the user. Applies to subscriptions and instant notifications. In case of instant notifications that have not received an object, the hook will be called as 'prepare', 'notification:<action>'. In case of instant notifications that have not received an action name, it will default to notify_user.

$params include:

event - \Elgg\Notifications\NotificationEvent instance that describes the notification event

object - object of the notification event. Can be null for instant notifications

action - action that triggered the notification event. May default to notify_user for instant notifications

method - delivery method (e.g. email, site)

sender - sender

recipient - recipient

language - language of the notification (recipient’s language)

origin - subscriptions_service or instant_notifications

format, notification:<method>

This hook can be used to format a notification before it is passed to the 'send', 'notification:<method>' hook. Applies to subscriptions and instant notifications. The hook handler should return an instance of \Elgg\Notifications\Notification. The hook does not receive any $params. Some of the use cases include:

Strip tags from notification title and body for plaintext email notifications

Inline HTML styles for HTML email notifications

Wrap notification in a template, add signature etc.

send, notification:<method>

Delivers a notification. Applies to subscriptions and instant notifications. The handler must return true or false indicating the success of the delivery.

$params array includes:

notification - a notification object \Elgg\Notifications\Notification

send:after, notifications

Triggered after all notifications in the queue for the notifications event have been processed. Applies to subscriptions and instant notifications.

$params array includes:

event - \Elgg\Notifications\NotificationEvent instance that describes the notification event

subscriptions - a list of subscriptions. See 'get', 'subscriptions' hook for details

deliveries - a matrix of delivery statuses by user for each delivery method

Emails¶

prepare, system:email

Triggered by elgg_send_email(). Applies to all outgoing system and notification emails. This hook allows you to alter an instance of \Elgg\Email before it is passed to the email transport. This hook can be used to alter the sender, recipient, subject, body, and/or headers of the email.

$params are empty. The $return value is an instance of \Elgg\Email.

validate, system:email

Triggered by elgg_send_email(). Applies to all outgoing system and notification emails. This hook allows you to suppress or whitelist outgoing emails, e.g. when the site is in a development mode. The handler must return false to supress the email delivery.

$params contains:

email - An instance of \Elgg\Email

transport, system:email

Triggered by elgg_send_email(). Applies to all outgoing system and notification emails. This hook allows you to implement a custom email transport, e.g. delivering emails via a third-party proxy service such as SendGrid or Mailgun. The handler must return true to indicate that the email was transported.

$params contains:

email - An instance of \Elgg\Email

zend:message, system:email

Triggered by the default email transport handler (Elgg uses zendframework/zend-mail). Applies to all outgoing system and notification emails that were not transported using the transport, system:email hook. This hook allows you to alter an instance of \Zend\Mail\Message before it is passed to the Zend email transport.

$params contains:

email - An instance of \Elgg\Email

Routing¶

route:config, <route_name>: Allows altering the route configuration before it is registered. This hook can be used to alter the path, default values, requirements, as well as to set/remove middleware. Please note that the handler for this hook should be registered outside of the init event handler, as core routes are registered during plugins_boot event.
route:rewrite, <identifier>: Allows altering the site-relative URL path for an incoming request. See Routing for details. Please note that the handler for this hook should be registered outside of the init event handler, as route rewrites take place after plugins_boot event has completed.
response, path:<path>: Filter an instance of \Elgg\Http\ResponseBuilder before it is sent to the client. This hook type will only be used if the path did not start with „action/“ or „ajax/“. This hook can be used to modify response content, status code, forward URL, or set additional response headers. Note that the <path> value is parsed from the request URL, therefore plugins using the route hook should use the original <path> to filter the response, or switch to using the route:rewrite hook.
ajax_response, path:<path>: Filters ajax responses before they’re sent back to the elgg/Ajax module. This hook type will only be used if the path did not start with „action/“ or „ajax/“.

Views¶

view_vars, <view_name>

Filters the $vars array passed to the view

view, <view_name>

Filters the returned content of the view

layout, page

In elgg_view_layout(), filters the layout name. $params array includes:

identifier - ID of the page being rendered

segments - URL segments of the page being rendered

other $vars received by elgg_view_layout()

shell, page

In elgg_view_page(), filters the page shell name

head, page

In elgg_view_page(), filters $vars['head'] Return value contains an array with title, metas and links keys, where metas is an array of elements to be formatted as <meta> head tags, and links is an array of elements to be formatted as <link> head tags. Each meta and link element contains a set of key/value pairs that are formatted into html tag attributes, e.g.

return [
   'title' => 'Current page title',
   'metas' => [
      'viewport' => [
         'name' => 'viewport',
         'content' => 'width=device-width',
      ]
   ],
   'links' => [
      'rss' => [
         'rel' => 'alternative',
         'type' => 'application/rss+xml',
         'title' => 'RSS',
         'href' => elgg_format_url($url),
      ],
      'icon-16' => [
         'rel' => 'icon',
         'sizes' => '16x16',
         'type' => 'image/png',
         'href' => elgg_get_simplecache_url('graphics/favicon-16.png'),
      ],
   ],
];

ajax_response, view:<view>: Filters ajax/view/ responses before they’re sent back to the elgg/Ajax module.
ajax_response, form:<action>: Filters ajax/form/ responses before they’re sent back to the elgg/Ajax module.
response, view:<view_name>: Filter an instance of \Elgg\Http\ResponseBuilder before it is sent to the client. Applies to request to /ajax/view/<view_name>. This hook can be used to modify response content, status code, forward URL, or set additional response headers.
response, form:<form_name>: Filter an instance of \Elgg\Http\ResponseBuilder before it is sent to the client. Applies to request to /ajax/form/<form_name>. This hook can be used to modify response content, status code, forward URL, or set additional response headers.
table_columns:call, <name>: When the method elgg()->table_columns->$name() is called, this hook is called to allow plugins to override or provide an implementation. Handlers receive the method arguments via $params['arguments'] and should return an instance of Elgg\Views\TableColumn if they wish to specify the column directly.
vars:compiler, css: Allows plugins to alter CSS variables passed to CssCrush during compilation. See CSS variables <_guides/theming#css-vars>.

Files¶

download:url, file

Allows plugins to filter the download URL of the file.: By default, the download URL is generated by the file service.

$params array includes:

entity - instance of ElggFile

inline:url, file

Allows plugins to filter the inline URL of the image file.: By default, the inline URL is generated by the file service.

$params array includes:

entity - instance of ElggFile

mime_type, file

Return the mimetype for the filename $params['filename'] with original filename $params['original_filename'] and with the default detected mimetype of $params['default'].

simple_type, file

In elgg_get_file_simple_type(), filters the return value. The hook uses $params['mime_type'] (e.g. application/pdf or image/jpeg) and determines an overall category like document or image. The bundled file plugin and other-third party plugins usually store simpletype metadata on file entities and make use of it when serving icons and constructing ege* filters and menus.

upload, file

Allows plugins to implement custom logic for moving an uploaded file into an instance of ElggFile. The handler must return true to indicate that the uploaded file was moved. The handler must return false to indicate that the uploaded file could not be moved. Other returns will indicate that ElggFile::acceptUploadedFile should proceed with the default upload logic.

$params array includes:

file - instance of ElggFile to write to

upload - instance of Symfony’s UploadedFile

Search¶

search:results, <search_type>: Triggered by elgg_search(). Receives normalized options suitable for elgg_get_entities() call and must return an array of entities matching search options. This hook is designed for use by plugins integrating third-party indexing services, such as Solr and Elasticsearch.
search:params, <search_type>: Triggered by elgg_search(). Filters search parameters (query, sorting, search fields etc) before search clauses are prepared for a given search type. Elgg core only provides support for entities search type.
search:fields, <entity_type>: Triggered by elgg_search(). Filters search fields before search clauses are prepared. $return value contains an array of names for each entity property type, which should be matched against the search query. $params array contains an array of search params passed to and filtered by elgg_search().

return [
    'attributes' => [],
    'metadata' => ['title', 'description'],
    'annotations' => ['revision'],
    'private_settings' => ['internal_notes'],
];

search:fields, <entity_type>:<entity_subtype>: See search:fields, <entity_type>
search:fields, <search_type>: See search:fields, <entity_type>
search:options, <entity_type>: Triggered by elgg_search(). Prepares search clauses (options) to be passed to elgg_get_entities().
search:options, <entity_type>:<entity_subtype>: See search:options, <entity_type>
search:options, <search_type>: See search:options, <entity_type>
search:config, search_types: Implemented in the search plugin. Filters an array of custom search types. This allows plugins to add custom search types (e.g. tag or location search). Adding a custom search type will extend the search plugin user interface with appropriate links and lists.
search:config, type_subtype_pairs: Implemented in the search plugin. Filters entity type/subtype pairs before entity search is performed. Allows plugins to remove certain entity types/subtypes from search results, group multiple subtypes together, or to reorder search sections.
search:format, entity: Implemented in the search plugin. Allows plugins to populate entity’s volatile data before it’s passed to search view. This is used for highlighting search hit, extracting relevant substrings in long text fields etc.

Other¶

config, comments_per_page

Filters the number of comments displayed per page. Default is 25. $params['entity'] will hold the containing entity or null if not provided.

config, comments_latest_first

Filters the order of comments. Default is true for latest first. $params['entity'] will hold the containing entity or null if not provided.

default, access

In get_default_access(), this hook filters the return value, so it can be used to alter the default value in the input/access view. For core plugins, the value „input_params“ has the keys „entity“ (ElggEntity|false), „entity_type“ (string), „entity_subtype“ (string), „container_guid“ (int) are provided. An empty entity value generally means the form is to create a new object.

classes, icon

Can be used to filter CSS classes applied to icon glyphs. By default, Elgg uses FontAwesome. Plugins can use this hook to switch to a different font family and remap icon classes.

entity:icon:sizes, <entity_type>

Triggered by elgg_get_icon_sizes() and sets entity type/subtype specific icon sizes. entity_subtype will be passed with the $params array to the callback.

entity:<icon_type>:sizes, <entity_type>

Allows filtering sizes for custom icon types, see entity:icon:sizes, <entity_type>.

The hook must return an associative array where keys are the names of the icon sizes (e.g. „large“), and the values are arrays with the following keys:

w - Width of the image in pixels
h - Height of the image in pixels
square - Should the aspect ratio be a square (true/false)
upscale - Should the image be upscaled in case it is smaller than the given width and height (true/false)
crop - Is cropping allowed on this image size (true/false, default: true)

If the configuration array for an image size is empty, the image will be saved as an exact copy of the source without resizing or cropping.

Example:

return [
        'small' => [
                'w' => 60,
                'h' => 60,
                'square' => true,
                'upscale' => true,
        ],
        'large' => [
                'w' => 600,
                'h' => 600,
                'upscale' => false,
        ],
        'original' => [],
];

entity:icon:url, <entity_type>

Triggered when entity icon URL is requested, see entity icons. Callback should return URL for the icon of size $params['size'] for the entity $params['entity']. Following parameters are available through the $params array:

entity: Entity for which icon url is requested.
viewtype: The type of view e.g. 'default' or 'json'.
size: Size requested, see entity icons for possible values.

Example on how one could default to a Gravatar icon for users that have not yet uploaded an avatar:

// Priority 600 so that handler is triggered after avatar handler
elgg_register_plugin_hook_handler('entity:icon:url', 'user', 'gravatar_icon_handler', 600);

/**
 * Default to icon from gravatar for users without avatar.
 */
function gravatar_icon_handler($hook, $type, $url, $params) {
        // Allow users to upload avatars
        if ($params['entity']->icontime) {
                return $url;
        }

        // Generate gravatar hash for user email
        $hash = md5(strtolower(trim($params['entity']->email)));

        // Default icon size
        $size = '150x150';

        // Use configured size if possible
        $config = elgg_get_icon_sizes('user');
        $key = $params['size'];
        if (isset($config[$key])) {
                $size = $config[$key]['w'] . 'x' . $config[$key]['h'];
        }

        // Produce URL used to retrieve icon
        return "http://www.gravatar.com/avatar/$hash?s=$size";
}

entity:<icon_type>:url, <entity_type>

Allows filtering URLs for custom icon types, see entity:icon:url, <entity_type>

entity:icon:file, <entity_type>

Triggered by ElggEntity::getIcon() and allows plugins to provide an alternative ElggIcon object that points to a custom location of the icon on filestore. The handler must return an instance of ElggIcon or an exception will be thrown.

entity:<icon_type>:file, <entity_type>

Allows filtering icon file object for custom icon types, see entity:icon:file, <entity_type>

entity:<icon_type>:prepare, <entity_type>

Triggered by ElggEntity::saveIcon*() methods and can be used to prepare an image from uploaded/linked file. This hook can be used to e.g. rotate the image before it is resized/cropped, or it can be used to extract an image frame if the uploaded file is a video. The handler must return an instance of ElggFile with a simpletype that resolves to image. The $return value passed to the hook is an instance of ElggFile that points to a temporary copy of the uploaded/linked file.

The $params array contains:

entity - entity that owns the icons

file - original input file before it has been modified by other hooks

entity:<icon_type>:save, <entity_type>

Triggered by ElggEntity::saveIcon*() methods and can be used to apply custom image manipulation logic to resizing/cropping icons. The handler must return true to prevent the core APIs from resizing/cropping icons. The $params array contains:

entity - entity that owns the icons

file - ElggFile object that points to the image file to be used as source for icons

x1, y1, x2, y2 - cropping coordinates

entity:<icon_type>:saved, <entity_type>

Triggered by ElggEntity::saveIcon*() methods once icons have been created. This hook can be used by plugins to create river items, update cropping coordinates for custom icon types etc. The handler can access the created icons using ElggEntity::getIcon(). The $params array contains:

entity - entity that owns the icons

x1, y1, x2, y2 - cropping coordinates

entity:<icon_type>:delete, <entity_type>

Triggered by ElggEntity::deleteIcon() method and can be used for clean up operations. This hook is triggered before the icons are deleted. The handler can return false to prevent icons from being deleted. The $params array contains:

entity - entity that owns the icons

entity:url, <entity_type>

Return the URL for the entity $params['entity']. Note: Generally it is better to override the getUrl() method of ElggEntity. This hook should be used when it’s not possible to subclass (like if you want to extend a bundled plugin without overriding many views).

to:object, <entity_type|metadata|annotation|relationship|river_item>

Converts the entity $params['entity'] to a StdClass object. This is used mostly for exporting entity properties for portable data formats like JSON and XML.

extender:url, <annotation|metadata>

Return the URL for the annotation or metadatum $params['extender'].

file:icon:url, override

Override a file icon URL.

is_member, group

Return boolean for if the user $params['user'] is a member of the group $params['group'].

entity:annotate, <entity_type>

Triggered in elgg_view_entity_annotations(), which is called by elgg_view_entity(). Can be used to add annotations to all full entity views.

usersetting, plugin

Filter user settings for plugins. $params contains:

user - An ElggUser instance
plugin - An ElggPlugin instance
plugin_id - The plugin ID
name - The name of the setting
value - The value to set

setting, plugin

Filter plugin settings. $params contains:

plugin - An ElggPlugin instance
plugin_id - The plugin ID
name - The name of the setting
value - The value to set

relationship:url, <relationship_name>

Filter the URL for the relationship object $params['relationship'].

profile:fields, group

Filter an array of profile fields. The result should be returned as an array in the format name => input view name. For example:

array(
        'about' => 'longtext'
);

profile:fields, profile: Filter an array of profile fields. The result should be returned as an array in the format name => input view name. For example:

array(
        'about' => 'longtext'
);

widget_settings, <widget_handler>: Triggered when saving a widget settings $params['params'] for widget $params['widget']. If handling saving the settings, the handler should return true to prevent the default code from running.
handlers, widgets: Triggered when a list of available widgets is needed. Plugins can conditionally add or remove widgets from this list or modify attributes of existing widgets like context or multiple.
get_list, default_widgets: Filters a list of default widgets to add for newly registered users. The list is an array of arrays in the format:

array(
        'event' => $event,
        'entity_type' => $entity_type,
        'entity_subtype' => $entity_subtype,
        'widget_context' => $widget_context
)

public_pages, walled_garden

Filters a list of URLs (paths) that can be seen by logged out users in a walled garden mode. Handlers must return an array of regex strings that will allow access if matched. Please note that system public routes are passed as the default value to the hook, and plugins must take care to not accidentally override these values.

The $params array contains:

url - URL of the page being tested for public accessibility

volatile, metadata

Triggered when exporting an entity through the export handler. This is rare. This allows handler to handle any volatile (non-persisted) metadata on the entity. It’s preferred to use the to:object, <type> hook.

maintenance:allow, url

Return boolean if the URL $params['current_url'] and the path $params['current_path']: is allowed during maintenance mode.

robots.txt, site

Filter the robots.txt values for $params['site'].

config, amd

Filter the AMD config for the requirejs library.

Plugins¶

Embed¶

embed_get_items, <active_section>

embed_get_sections, all

embed_get_upload_sections, all

Groups¶

profile_buttons, group

Filters buttons (ElggMenuItem instances) to be registered in the title menu of the group profile page

tool_options, group

Filters a collection of tools available within a specific group:

The $return is \Elgg\Collections\Collection<\Elgg\Groups\Tool>, a collection of group tools.

The $params array contains:

entity - \ElggGroup

HTMLawed¶

allowed_styles, htmlawed: Filter the HTMLawed allowed style array.
config, htmlawed: Filter the HTMLawed $config array.
spec, htmlawed: Filter the HTMLawed $spec string (default empty).

Likes¶

likes:is_likable, <type>:<subtype>: This is called to set the default permissions for whether to display/allow likes on an entity of type <type> and subtype <subtype>.

Bemerkung

The callback 'Elgg\Values::getTrue' is a useful handler for this hook.

Members¶

members:list, <page_segment>: To handle the page /members/$page_segment, register for this hook and return the HTML of the list.
members:config, tabs: This hook is used to assemble an array of tabs to be passed to the navigation/tabs view for the members pages.

Reported Content¶

reportedcontent:add, system: Triggered after adding the reported content object $params['report']. Return false to delete report.
reportedcontent:archive, system: Triggered before archiving the reported content object $params['report']. Return false to prevent archiving.
reportedcontent:delete, system: Triggered before deleting the reported content object $params['report']. Return false to prevent deleting.

Web Services¶

rest, init: Triggered by the web services rest handler. Plugins can set up their own authentication handlers, then return true to prevent the default handlers from being registered.
rest:output, <method_name>: Filter the result (and subsequently the output) of the API method

Internationalization¶

Make your UI translatable into many different languages.

If you’d like to contribute translations to Elgg, see the contributors‘ guide.

The default language is en for English. Elgg uses a fallback system for languages:

The language of the user
The site language
English

Overview¶

Translations are stored in PHP files in the /languages directory of your plugin. Each file corresponds to a language. The format is /languages/{language-code}.php where {language-code} is the ISO 639-1 short code for the language. For example:

<?php // mod/example/languages/en.php

return [
        'example:text' => 'Some example text',
];

To override an existing translation, include it in your plugin’s language file, and make sure your plugin is ordered later on the Admin > Plugins page:

<?php // mod/better_example/languages/en.php

return [
        'example:text' => 'Some better text!',
];

Bemerkung

Unless you are overriding core’s or another plugin’s language strings, it is good practice for the language keys to start with your plugin name. For example: yourplugin:success, yourplugin:title, etc. This helps avoid conflicts with other language keys.

Server-side API¶

elgg_echo($key, $args, $language)

Output the translation of the key in the current language.

Example:

echo elgg_echo('example:text');

It also supports variable replacement using vsprintf syntax:

// 'welcome' => 'Welcome to %s, %s!'
echo elgg_echo('welcome', [
        elgg_get_config('sitename'),
        elgg_get_logged_in_user_entity()->getDisplayName(),
]);

To force which language should be used for translation, set the third parameter:

echo elgg_echo('welcome', [], $user->language);

To first test whether elgg_echo() can find a translation:

$key = 'key:that:might:not:exist';
if (!elgg_language_key_exists($key)) {
        $key = 'fallback:key';
}

echo elgg_echo($key);

Bemerkung

Some APIs allow creating translations for new keys. Translators should always include an English translation as a fallback. This makes elgg_language_key_exists($key) a reliable way to predict whether elgg_echo($key) will succeed.

Javascript API¶

elgg.echo(key, args)

This function is like elgg_echo in PHP.

Client-side translations are loaded asynchronously. Ensure translations are available by requiring the „elgg“ AMD module:

define(function(require) {
        var elgg = require("elgg");

        alert(elgg.echo('my_key'));
});

Translations are also available after the init, system JavaScript event.

JavaScript¶

Contents

AMD ¶

Developers should use the AMD (Asynchronous Module Definition) standard for writing JavaScript code in Elgg.

Here we’ll describe making and executing AMD modules. The RequireJS documentation for defining modules may also be of use.

Executing a module in the current page ¶

Telling Elgg to load an existing module in the current page is easy:

<?php
elgg_require_js("myplugin/say_hello");

On the client-side, this will asynchronously load the module, load any dependencies, and execute the module’s definition function, if it has one.

Defining the Module ¶

Here we define a basic module that alters the page, by passing a „definition function“ to define():

// in views/default/myplugin/say_hello.js

define(function(require) {
    var elgg = require("elgg");
    var $ = require("jquery");

    $('body').append(elgg.echo('hello_world'));
});

The module’s name is determined by the view name, which here is myplugin/say_hello.js. We strip the .js extension, leaving myplugin/say_hello.

Warnung

The definition function must have one argument named require.

Making modules dependent on other modules ¶

Below we refactor a bit so that the module depends on a new myplugin/hello module to provide the greeting:

// in views/default/myplugin/hello.js

define(function(require) {
    var elgg = require("elgg");

    return elgg.echo('hello_world');
});

// in views/default/myplugin/say_hello.js

define(function(require) {
    var $ = require("jquery");
    var hello = require("myplugin/hello");

    $('body').append(hello);
});

Passing settings to modules ¶

The elgg.data plugin hooks¶

The elgg module provides an object elgg.data which is populated from two server side hooks:

elgg.data, site: This filters an associative array of site-specific data passed to the client and cached.
elgg.data, page: This filters an associative array of uncached, page-specific data passed to the client.

Let’s pass some data to a module:

<?php

function myplugin_config_site($hook, $type, $value, $params) {
    // this will be cached client-side
    $value['myplugin']['api'] = elgg_get_site_url() . 'myplugin-api';
    $value['myplugin']['key'] = 'none';
    return $value;
}

function myplugin_config_page($hook, $type, $value, $params) {
    $user = elgg_get_logged_in_user_entity();
    if ($user) {
        $value['myplugin']['key'] = $user->myplugin_api_key;
        return $value;
    }
}

elgg_register_plugin_hook_handler('elgg.data', 'site', 'myplugin_config_site');
elgg_register_plugin_hook_handler('elgg.data', 'page', 'myplugin_config_page');

define(function(require) {
    var elgg = require("elgg");

    var api = elgg.data.myplugin.api;
    var key = elgg.data.myplugin.key; // "none" or a user's key

    // ...
});

Bemerkung

In elgg.data, page data overrides site data. Also note json_encode() is used to copy data client-side, so the data must be JSON-encodable.

Making a config module¶

You can use a PHP-based module to pass values from the server. To make the module myplugin/settings, create the view file views/default/myplugin/settings.js.php (note the double extension .js.php).

<?php

// this will be cached client-side
$settings = [
    'api' => elgg_get_site_url() . 'myplugin-api',
    'key' => null,
];
?>
define(<?php echo json_encode($settings); ?>);

You must also manually register the view as an external resource:

<?php
// note the view name does not include ".php"
elgg_register_simplecache_view('myplugin/settings.js');

Bemerkung

The PHP view is cached, so you should treat the output as static (the same for all users) and avoid session-specific logic.

Setting the URL of a module ¶

You may have an AMD script outside your views you wish to make available as a module.

The best way to accomplish this is by configuring the path to the file using the views section of the elgg-plugin.php file in the root of your plugin:

<?php // elgg-plugin.php
return [
    'views' => [
            'default' => [
                'underscore.js' => 'vendor/bower-asset/underscore/underscore.min.js',
            ],
    ],
];

If you’ve copied the script directly into your plugin instead of managing it with Composer, you can use something like this instead:

<?php // elgg-plugin.php
return [
    'views' => [
            'default' => [
                'underscore.js' => __DIR__ . '/bower_components/underscore/underscore.min.js',
            ],
    ],
];

That’s it! Elgg will now load this file whenever the „underscore“ module is requested.

Using traditional JS libraries as modules ¶

It’s possible to support JavaScript libraries that do not declare themselves as AMD modules (i.e. they declare global variables instead) if you shim them by setting exports and deps in elgg_define_js:

// set the path, define its dependencies, and what value it returns
elgg_define_js('jquery.form', [
    'deps' => ['jquery'],
    'exports' => 'jQuery.fn.ajaxForm',
]);

When this is requested client-side:

The jQuery module is loaded, as it’s marked as a dependency.
https://elgg.example.org/cache/125235034/views/default/jquery.form.js is loaded and executed.
The value of window.jQuery.fn.ajaxForm is returned by the module.

Warnung

Calls to elgg_define_js() must be in an init, system event handler.

Some things to note¶

Do not use elgg.provide() anymore nor other means to attach code to elgg or other global objects. Use modules.
Return the value of the module instead of adding to a global variable.
Static (.js,.css,etc.) files are automatically minified and cached by Elgg’s simplecache system.
The configuration is also cached in simplecache, and should not rely on user-specific values like get_current_language().

Booting your plugin ¶

To add functionality to each page, or make sure your hook handlers are registered early enough, you may create a boot module for your plugin, with the name boot/<plugin_id>.

// in views/default/boot/example.js

define(function(require) {
    var elgg = require("elgg");
    var Plugin = require("elgg/Plugin");

    // plugin logic
    function my_init() { ... }

    return new Plugin({
        // executed in order of plugin priority
        init: function () {
            elgg.register_hook_handler("init", "system", my_init, 400);
        }
    });
});

When your plugin is active, this module will automatically be loaded on each page. Other modules can depend on elgg/init to make sure all boot modules are loaded.

Each boot module must return an instance of elgg/Plugin. The constructor must receive an object with a function in the init key. The init function will be called in the order of the plugin in Elgg’s admin area.

Bemerkung

Though not strictly necessary, you may want to use the init, system event to control when your initialization code runs with respect to other modules.

Warnung

A boot module cannot depend on the modules elgg/init or elgg/ready.

Modules provided with Elgg ¶

Modules `jquery` and `jquery-ui`¶

You must depend on these modules to use $ or $.ui methods. In the future Elgg may stop loading these by default.

Module `elgg`¶

elgg.echo()

Translate interface text

elgg.echo('example:text', ['arg1']);

elgg.system_message()

Display a status message to the user.

elgg.system_message(elgg.echo('success'));

elgg.register_error()

Display an error message to the user.

elgg.register_error(elgg.echo('error'));

elgg.normalize_url()

Normalize a URL relative to the elgg root:

// "http://localhost/elgg/blog"
elgg.normalize_url('/blog');

elgg.forward()

Redirect to a new page.

elgg.forward('/blog');

This function automatically normalizes the URL.

elgg.parse_url()

Parse a URL into its component parts:

// returns {
//   fragment: "fragment",
//   host: "community.elgg.org",
//   path: "/file.php",
//   query: "arg=val"
// }
elgg.parse_url('http://community.elgg.org/file.php?arg=val#fragment');

elgg.get_page_owner_guid()

Get the GUID of the current page’s owner.

elgg.register_hook_handler()

Register a hook handler with the event system. For best results, do this in a plugin boot module.

// boot module: /views/default/boot/example.js
define(function (require) {
    var elgg = require('elgg');
    var Plugin = require('elgg/Plugin');

    elgg.register_hook_handler('foo', 'bar', function () { ... });

    return new Plugin();
});

elgg.trigger_hook()

Emit a hook event in the event system. For best results depend on the elgg/init module.

// old
value = elgg.trigger_hook('my_plugin:filter', 'value', {}, value);

define(function (require) {
    require('elgg/init');
    var elgg = require('elgg');

    value = elgg.trigger_hook('my_plugin:filter', 'value', {}, value);
});

elgg.security.refreshToken()

Force a refresh of all XSRF tokens on the page.

This is automatically called every 5 minutes by default.

The user will be warned if their session has expired.

elgg.security.addToken()

Add a security token to an object, URL, or query string:

// returns {
//   __elgg_token: "1468dc44c5b437f34423e2d55acfdd87",
//   __elgg_ts: 1328143779,
//   other: "data"
// }
elgg.security.addToken({'other': 'data'});

// returns: "action/add?__elgg_ts=1328144079&__elgg_token=55fd9c2d7f5075d11e722358afd5fde2"
elgg.security.addToken("action/add");

// returns "?arg=val&__elgg_ts=1328144079&__elgg_token=55fd9c2d7f5075d11e722358afd5fde2"
elgg.security.addToken("?arg=val");

elgg.get_logged_in_user_entity()

Returns the logged in user as an JS ElggUser object.

elgg.get_logged_in_user_guid()

Returns the logged in user’s guid.

elgg.is_logged_in()

True if the user is logged in.

elgg.is_admin_logged_in()

True if the user is logged in and is an admin.

elgg.config.get_language()

Get the current page’s language.

There are a number of configuration values set in the elgg object:

// The root of the website.
elgg.config.wwwroot;
// The default site language.
elgg.config.language;
// The current page's viewtype
elgg.config.viewtype;
// The Elgg version (YYYYMMDDXX).
elgg.config.version;
// The Elgg release (X.Y.Z).
elgg.config.release;

Module `elgg/Ajax`¶

See the Ajax page for details.

Module `elgg/init`¶

elgg/init loads and initializes all boot modules in priority order and triggers the [init, system] hook.

Require this module to make sure all plugins are ready.

Module `elgg/Plugin`¶

Used to create a boot module.

Module `elgg/ready`¶

elgg/ready loads and initializes all plugin boot modules in priority order.

Require this module to make sure all plugins are ready.

Module `elgg/spinner`¶

The elgg/spinner module can be used to create an Ajax loading indicator fixed to the top of the window.

define(function (require) {
   var spinner = require('elgg/spinner');

   elgg.action('friend/add', {
       beforeSend: spinner.start,
       complete: spinner.stop,
       success: function (json) {
           // ...
       }
   });
});

Bemerkung

The elgg/Ajax module uses the spinner by default.

Module `elgg/popup`¶

The elgg/popup module can be used to display an overlay positioned relatively to its anchor (trigger).

The elgg/popup module is loaded by default, and binding a popup module to an anchor is as simple as adding rel="popup" attribute and defining target module with a href (or data-href) attribute. Popup module positioning can be defined with data-position attribute of the trigger element.

echo elgg_format_element('div', [
   'class' => 'elgg-module-popup hidden',
   'id' => 'popup-module',
], 'Popup module content');

// Simple anchor
echo elgg_view('output/url', [
   'href' => '#popup-module',
   'text' => 'Show popup',
   'rel' => 'popup',
]);

// Button with custom positioning of the popup
echo elgg_format_element('button', [
   'rel' => 'popup',
   'class' => 'elgg-button elgg-button-submit',
   'text' => 'Show popup',
   'data-href' => '#popup-module',
   'data-position' => json_encode([
      'my' => 'center bottom',
      'at' => 'center top',
   ]),
]);

The elgg/popup module allows you to build out more complex UI/UX elements. You can open and close popup modules programmatically:

define(function(require) {
   var $ = require('jquery');
   $(document).on('click', '.elgg-button-popup', function(e) {

      e.preventDefault();

      var $trigger = $(this);
      var $target = $('#my-target');
      var $close = $target.find('.close');

      require(['elgg/popup'], function(popup) {
         popup.open($trigger, $target, {
            'collision': 'fit none'
         });

         $close.on('click', popup.close);
      });
   });
});

You can use getOptions, ui.popup plugin hook to manipulate the position of the popup before it has been opened. You can use jQuery open and close events to manipulate popup module after it has been opened or closed.

define(function(require) {

   var elgg = require('elgg');
   var $ = require('jquery');

   $('#my-target').on('open', function() {
      var $module = $(this);
      var $trigger = $module.data('trigger');

      elgg.ajax('ajax/view/my_module', {
         beforeSend: function() {
            $trigger.hide();
            $module.html('').addClass('elgg-ajax-loader');
         },
         success: function(output) {
            $module.removeClass('elgg-ajax-loader').html(output);
         }
      });
   }).on('close', function() {
      var $trigger = $(this).data('trigger');
      $trigger.show();
   });
});

Open popup modules will always contain the following data that can be accessed via $.data():

trigger - jQuery element used to trigger the popup module to open

position - An object defining popup module position that was passed to $.position()

By default, target element will be appended to $('body') thus altering DOM hierarchy. If you need to preserve the DOM position of the popup module, you can add .elgg-popup-inline class to your trigger.

Module `elgg/widgets`¶

Plugins that load a widget layout via Ajax should initialize via this module:

require(['elgg/widgets'], function (widgets) {
    widgets.init();
});

Module `elgg/ckeditor`¶

This module can be used to add WYSIWYG editor to a textarea (requires ckeditor plugin to be enabled). Note that WYSIWYG will be automatically attached to all instances of .elgg-input-longtext.

require(['elgg/ckeditor'], function (elggCKEditor) {
   elggCKEditor.bind('#my-text-area');

   // Toggle CKEditor
   elggCKEditor.toggle('#my-text-area');

   // Focus on CKEditor input
   elggCKEditor.focus('#my-text-area');
   // or
   $('#my-text-area').trigger('focus');

   // Reset CKEditor input
   elggCKEditor.reset('#my-text-area');
   // or
   $('#my-text-area').trigger('reset');

});

Inline tabs component ¶

Inline tabs component fires an open event whenever a tabs is open and, in case of ajax tabs, finished loading:

// Add custom animation to tab content
require(['jquery', 'elgg/ready'], function($) {
        $(document).on('open', '.theme-sandbox-tab-callback', function() {
                $(this).find('a').text('Clicked!');
                $(this).data('target').hide().show('slide', {
                        duration: 2000,
                        direction: 'right',
                        complete: function() {
                                alert('Thank you for clicking. We hope you enjoyed the show!');
                                $(this).css('display', ''); // .show() adds display property
                        }
                });
        });
});

Traditional scripts ¶

Although we highly recommend using AMD modules, and there is no Elgg API for loading the scripts, you can register scripts in a hook handler to add elements to the head links;

elgg_register_plugin_hook_handler('head', 'page', $callback);

Hooks ¶

The JS engine has a hooks system similar to the PHP engine’s plugin hooks: hooks are triggered and plugins can register functions to react or alter information. There is no concept of Elgg events in the JS engine; everything in the JS engine is implemented as a hook.

Registering hook handlers ¶

Handler functions are registered using elgg.register_hook_handler(). Multiple handlers can be registered for the same hook.

The following example registers the handleFoo function for the foo, bar hook.

define(function (require) {
    var elgg = require('elgg');
    var Plugin = require('elgg/Plugin');

    function handleFoo(hook, type, params, value) {
        // do something
    }

    elgg.register_hook_handler('foo', 'bar', handleFoo);

    return new Plugin();
});

The handler function ¶

The handler will receive 4 arguments:

hook - The hook name
type - The hook type
params - An object or set of parameters specific to the hook
value - The current value

The value will be passed through each hook. Depending on the hook, callbacks can simply react or alter data.

Triggering custom hooks ¶

Plugins can trigger their own hooks:

define(function(require) {
    require('elgg/init');
    var elgg = require('elgg');

    elgg.trigger_hook('name', 'type', {params}, "value");
});

Bemerkung

Be aware of timing. If you don’t depend on elgg/init, other plugins may not have had a chance to register their handlers.

Available hooks ¶

init, system: Plugins should register their init functions for this hook. It is fired after Elgg’s JS is loaded and all plugin boot modules have been initialized. Depend on the elgg/init module to be sure this has completed.
ready, system: This hook is fired when the system has fully booted (after init). Depend on the elgg/ready module to be sure this has completed.
getOptions, ui.popup: This hook is fired for pop up displays ("rel"="popup") and allows for customized placement options.
getOptions, ui.lightbox: This hook can be used to filter options passed to $.colorbox()
config, ckeditor: This filters the CKEditor config object. Register for this hook in a plugin boot module. The defaults can be seen in the module elgg/ckeditor/config.
prepare, ckeditor: This hook can be used to decorate CKEDITOR global. You can use this hook to register new CKEditor plugins and add event bindings.
ajax_request_data, *: This filters request data sent by the elgg/Ajax module. See Ajax for details. The hook must check if the data is a plain object or an instanceof FormData to piggyback the values using correct API.
ajax_response_data, *: This filters the response data returned to users of the elgg/Ajax module. See Ajax for details.
insert, editor: This hook is triggered by the embed plugin and can be used to filter content before it is inserted into the textarea. This hook can also be used by WYSIWYG editors to insert content using their own API (in this case the handler should return false). See ckeditor plugin for an example.

Third-party assets ¶

We recommend managing third-party scripts and styles with Composer. Elgg’s composer.json is configured to install dependencies from the Bower or Yarn package repositories using Composer command-line tool. Core configuration installs the assets from Asset Packagist (a repository managed by the Yii community).

Alternatively, you can install fxp/composer-asset-plugin globally to achieve the same results, but the installation and update takes much longer.

For example, to include jQuery, you could run the following Composer commands:

composer require bower-asset/jquery:~2.0

If you are using a starter-project, or pulling in Elgg as a composer dependency via a custom composer project, update your composer.json with the following configuration:

{
    "repositories": [
        {
            "type": "composer",
            "url": "https://asset-packagist.org"
        }
    ],
        "config": {
        "fxp-asset": {
            "enabled": false
        }
    },
}

You can find additional information at Asset Packagist website.

Menus¶

Elgg contains helper code to build menus throughout the site.

Every single menu requires a name, as does every single menu item. These are required in order to allow easy overriding and manipulation, as well as to provide hooks for theming.

Contents

Basic usage
Admin menu
Advanced usage
Creating a new menu
Child Dropdown Menus
Theming
Toggling Menu Items
JavaScript

Basic usage ¶

Basic functionalities can be achieved through these two functions:

elgg_register_menu_item() to add an item to a menu

elgg_unregister_menu_item() to remove an item from a menu

You normally want to call them from your plugin’s init function.

Examples¶

// Add a new menu item to the site main menu
elgg_register_menu_item('site', array(
        'name' => 'itemname',
        'text' => 'This is text of the item',
        'href' => '/item/url',
));

// Remove the "Elgg" logo from the topbar menu
elgg_unregister_menu_item('topbar', 'elgg_logo');

Advanced usage ¶

You can get more control over menus by using plugin hooks and the public methods provided by the ElggMenuItem class.

There are three hooks that can be used to modify a menu:

'parameters', 'menu:<menu name>' to add or modify parameters use for the menu building (eg. sorting)
'register', 'menu:<menu name>' to add or modify items (especially in dynamic menus)
'prepare', 'menu:<menu name>' to modify the structure of the menu before it is displayed

When you register a plugin hook handler, replace the <menu name> part with the internal name of the menu.

The third parameter passed into a menu handler contains all the menu items that have been registered so far by Elgg core and other enabled plugins. In the handler we can loop through the menu items and use the class methods to interact with the properties of the menu item.

Examples¶

Example 1: Change the URL for menu item called „albums“ in the owner_block menu:

/**
 * Initialize the plugin
 */
function my_plugin_init() {
        // Register a plugin hook handler for the owner_block menu
        elgg_register_plugin_hook_handler('register', 'menu:owner_block', 'my_owner_block_menu_handler');
}

/**
 * Change the URL of the "Albums" menu item in the owner_block menu
 */
function my_owner_block_menu_handler($hook, $type, $items, $params) {
        $owner = $params['entity'];

        // Owner can be either user or a group, so we
        // need to take both URLs into consideration:
        switch ($owner->getType()) {
                case 'user':
                        $url = "album/owner/{$owner->guid}";
                        break;
                case 'group':
                        $url = "album/group/{$owner->guid}";
                        break;
        }

        if ($items->has('albums')) {
                $items->get('albums')->setURL($url);
        }

        return $items;
}

Example 2: Modify the entity menu for the ElggBlog objects

Remove the thumb icon
Change the „Edit“ text into a custom icon

/**
 * Initialize the plugin
 */
function my_plugin_init() {
        // Register a plugin hook handler for the entity menu
        elgg_register_plugin_hook_handler('register', 'menu:entity', 'my_entity_menu_handler');
}

/**
 * Customize the entity menu for ElggBlog objects
 */
function my_entity_menu_handler($hook, $type, $items, $params) {
        // The entity can be found from the $params parameter
        $entity = $params['entity'];

        // We want to modify only the ElggBlog objects, so we
        // return immediately if the entity is something else
        if (!$entity instanceof ElggBlog) {
                return $menu;
        }

        $items->remove('likes');

        if ($items->has('edit')) {
                $items->get('edit')->setText('Modify');
                $items->get('edit')->icon = 'pencil';
        }

        return $items;
}

Creating a new menu ¶

Elgg provides multiple different menus by default. Sometimes you may however need some menu items that don’t fit in any of the existing menus. If this is the case, you can create your very own menu with the elgg_view_menu() function. You must call the function from the view, where you want to menu to be displayed.

Example: Display a menu called „my_menu“ that displays it’s menu items in alphapetical order:

// in a resource view
echo elgg_view_menu('my_menu', array('sort_by' => 'text'));

You can now add new items to the menu like this:

// in plugin init
elgg_register_menu_item('my_menu', array(
        'name' => 'my_page',
        'href' => 'path/to/my_page',
        'text' => elgg_echo('my_plugin:my_page'),
));

Furthermore it is now possible to modify the menu using the hooks 'register', 'menu:my_menu' and 'prepare', 'menu:my_menu'.

Theming ¶

The menu name, section names, and item names are all embedded into the HTML as CSS classes (normalized to contain only hyphens, rather that underscores or colons). This increases the size of the markup slightly but provides themers with a high degree of control and flexibility when styling the site.

Example: The following would be the output of the foo menu with sections alt and default containing items baz and bar respectively.

<ul class="elgg-menu elgg-menu-foo elgg-menu-foo-alt">
        <li class="elgg-menu-item elgg-menu-item-baz"></li>
</ul>
<ul class="elgg-menu elgg-menu-foo elgg-menu-foo-default">
        <li class="elgg-menu-item elgg-menu-item-bar"></li>
</ul>

Toggling Menu Items ¶

There are situations where you wish to toggle menu items that are actions that are the opposite of each other and ajaxify them. E.g. like/unlike, friend/unfriend, ban/unban, etc. Elgg has built-in support for this kind of actions. When you register a menu item you can provide a name of the menu item (in the same menu) that should be toggled. An ajax call will be made using the href of the menu item.

elgg_register_menu_item('my_menu', [
        'name' => 'like',
        'data-toggle' => 'unlike',
        'href' => 'action/like',
        'text' => elgg_echo('like'),
]);

elgg_register_menu_item('my_menu', [
        'name' => 'unlike',
        'data-toggle' => 'like',
        'href' => 'action/unlike',
        'text' => elgg_echo('unlike'),
]);

Bemerkung

The menu items are optimistically toggled. This means the menu items are toggled before the actions finish. If the actions fail, the menu items will be toggled back.

JavaScript ¶

It is common that menu items rely on JavaScript. You can bind client-side events to menu items by placing your JavaScript into AMD module and defining the requirement during the registration.

elgg_register_menu_item('my_menu', array(
        'name' => 'hide_on_click',
        'href' => '#',
        'text' => elgg_echo('hide:on:click'),
        'item_class' => '.hide-on-click',
        'deps' => ['navigation/menu/item/hide_on_click'],
));

// in navigation/menu/item/hide_on_click.js
define(function(require) {
    var $ = require('jquery');

    $(document).on('click', '.hide-on-click', function(e) {
        e.preventDefault();
        $(this).hide();
    });
});

Notifications¶

There are two ways to send notifications in Elgg:

Instant notifications
Event-based notifications send using a notifications queue

Contents

Instant notifications
Enqueued notifications
Registering a new notification method
Sending the notifications using your own method
Subscriptions
E-mail attachments

Instant notifications ¶

The generic method to send a notification to a user is via the function notify_user(). It is normally used when we want to notify only a single user. Notification like this might for example inform that someone has liked or commented the user’s post.

The function usually gets called in an action file.

Example:¶

In this example a user ($user) is triggering an action to rate a post created by another user ($owner). After saving the rating (ElggAnnotation $rating) to database, we could use the following code to send a notification about the new rating to the owner.

// Subject of the notification
$subject = elgg_echo('ratings:notification:subject', array(), $owner->language);

// Summary of the notification
$summary = elgg_echo('ratings:notification:summary', array($user->getDisplayName()), $owner->language);

// Body of the notification message
$body = elgg_echo('ratings:notification:body', array(
        $user->getDisplayName(),
        $owner->getDisplayName(),
        $rating->getValue() // A value between 1-5
), $owner->language);

$params = array(
        'object' => $rating,
        'action' => 'create',
        'summary' => $summary
);

// Send the notification
notify_user($owner->guid, $user->guid, $subject, $body, $params);

Bemerkung

The language used by the recipient isn’t necessarily the same as the language of the person who triggers the notification. Therefore you must always remember to pass the recipient’s language as the third parameter to elgg_echo().

Bemerkung

The 'summary' parameter is meant for notification plugins that only want to display a short message instead of both the subject and the body. Therefore the summary should be terse but still contain all necessary information.

Enqueued notifications ¶

On large sites there may be many users who have subscribed to receive notifications about a particular event. Sending notifications immediately when a user triggers such an event might remarkably slow down page loading speed. This is why sending of such notifications shoud be left for Elgg’s notification queue.

New notification events can be registered with the elgg_register_notification_event() function. Notifications about registered events will be sent automatically to all subscribed users.

This is the workflow of the notifications system:

Someone does an action that triggers an event within Elgg

The action can be create, update or delete

The target of the action can be any instance of the ElggEntity class (e.g. a Blog post)

The notifications system saves this event into a notifications queue in the database

When the pluging hook handler for the one-minute interval gets triggered, the event is taken from the queue and it gets processed

Subscriptions are fetched for the user who triggered the event

By default this includes all the users who have enabled any notification method for the user at www.site.com/notifications/personal/<username>

Plugins are allowed to alter the subscriptions using the [get, subscriptions] hook

Plugins are allowed to terminate notifications queue processing with the [send:before, notifications] hook

Plugins are allowed to alter the notification parameters with the [prepare, notification] hook

Plugins are allowed to alter the notification subject/message/summary with the [prepare, notification:<action>:<type>:<subtype>] hook

Plugins are allowed to format notification subject/message/summary for individual delivery methods with [format, notification:<method>] hook

Notifications are sent to each subscriber using the methods they have chosen

Plugins can take over or prevent sending of each individual notification with the [send, notification:<method>] hook

The [send:after, notifications] hook is triggered for the event after all notifications have been sent

Example¶

Tell Elgg to send notifications when a new object of subtype „photo“ is created:

/**
 * Initialize the photos plugin
 */
function photos_init() {
        elgg_register_notification_event('object', 'photo', array('create'));
}

Bemerkung

In order to send the event-based notifications you must have the one-minute CRON interval configured.

Contents of the notification message can be defined with the 'prepare', 'notification:[action]:[type]:[subtype]' hook.

Example¶

Tell Elgg to use the function photos_prepare_notification() to format the contents of the notification when a new objects of subtype ‚photo‘ is created:

/**
 * Initialize the photos plugin
 */
function photos_init() {
    elgg_register_notification_event('object', 'photo', array('create'));
    elgg_register_plugin_hook_handler('prepare', 'notification:create:object:photo', 'photos_prepare_notification');
}

/**
 * Prepare a notification message about a new photo
 *
 * @param string                          $hook         Hook name
 * @param string                          $type         Hook type
 * @param Elgg_Notifications_Notification $notification The notification to prepare
 * @param array                           $params       Hook parameters
 * @return Elgg_Notifications_Notification
 */
function photos_prepare_notification($hook, $type, $notification, $params) {
    $entity = $params['event']->getObject();
    $owner = $params['event']->getActor();
    $recipient = $params['recipient'];
    $language = $params['language'];
    $method = $params['method'];

    // Title for the notification
    $notification->subject = elgg_echo('photos:notify:subject', [$entity->getDisplayName()], $language);

    // Message body for the notification
    $notification->body = elgg_echo('photos:notify:body', array(
        $owner->getDisplayName(),
        $entity->getDisplayName(),
        $entity->getExcerpt(),
        $entity->getURL()
    ), $language);

    // Short summary about the notification
    $notification->summary = elgg_echo('photos:notify:summary', [$entity->getDisplayName()], $language);

    return $notification;
}

Bemerkung

Make sure the notification will be in the correct language by passing the reciepient’s language into the elgg_echo() function.

Registering a new notification method ¶

By default Elgg has two notification methods: email and the bundled site_notifications plugin. You can register a new notification method with the elgg_register_notification_method() function.

Example:¶

Register a handler that will send the notifications via SMS.

/**
 * Initialize the plugin
 */
function sms_notifications_init () {
        elgg_register_notification_method('sms');
}

After registering the new method, it will appear to the notification settings page at www.example.com/notifications/personal/[username].

Sending the notifications using your own method ¶

Besides registering the notification method, you also need to register a handler that takes care of actually sending the SMS notifications. This happens with the 'send', 'notification:[method]' hook.

Example:¶

/**
 * Initialize the plugin
 */
function sms_notifications_init () {
        elgg_register_notification_method('sms');
        elgg_register_plugin_hook_handler('send', 'notification:sms', 'sms_notifications_send');
}

/**
 * Send an SMS notification
 *
 * @param string $hook   Hook name
 * @param string $type   Hook type
 * @param bool   $result Has anyone sent a message yet?
 * @param array  $params Hook parameters
 * @return bool
 * @internal
 */
function sms_notifications_send($hook, $type, $result, $params) {
        /* @var Elgg_Notifications_Notification $message */
        $message = $params['notification'];

        $recipient = $message->getRecipient();

        if (!$recipient || !$recipient->mobile) {
                return false;
        }

        // (A pseudo SMS API class)
        $sms = new SmsApi();

        return $sms->send($recipient->mobile, $message->body);
}

Subscriptions ¶

In most cases Elgg core takes care of handling the subscriptions, so notification plugins don’t usually have to alter them.

Subscriptions can however be:

Added using the elgg_add_subscription() function
Removed using the elgg_remove_subscription() function

It’s possible to modify the recipients of a notification dynamically with the 'get', 'subscriptions' hook.

Example:¶

/**
 * Initialize the plugin
 */
function discussion_init() {
        elgg_register_plugin_hook_handler('get', 'subscriptions', 'discussion_get_subscriptions');
}

/**
 * Get subscriptions for group notifications
 *
 * @param string $hook          'get'
 * @param string $type          'subscriptions'
 * @param array  $subscriptions Array containing subscriptions in the form
 *                       <user guid> => array('email', 'site', etc.)
 * @param array  $params        Hook parameters
 * @return array
 */
function discussion_get_subscriptions($hook, $type, $subscriptions, $params) {
        $reply = $params['event']->getObject();

        if (!$reply instanceof \ElggDiscussionReply) {
                return $subscriptions;
        }

        $group_guid = $reply->getContainerEntity()->container_guid;
        $group_subscribers = elgg_get_subscriptions_for_container($group_guid);

        return ($subscriptions + $group_subscribers);
}

E-mail attachments ¶

notify_user() or enqueued notifications support attachments for e-mail notifications if provided in $params. To add one or more attachments add a key attachments in $params which is an array of the attachments. An attachment should be in one of the following formats:

An ElggFile which points to an existing file
An array with the file contents
An array with a filepath

// this example is for notify_user()
$params['attachments'] = [];

// Example of an ElggFile attachment
$file = new \ElggFile();
$file->owner_guid = <some owner_guid>;
$file->setFilename('<some filename>');

$params['attachments'][] = $file;

// Example of array with content
$params['attachments'][] = [
        'content' => 'The file content',
        'filename' => 'test_file.txt',
        'type' => 'text/plain',
];

// Example of array with filepath
// 'filename' can be provided, if not basename() of filepath will be used
// 'type' can be provided, if not will try a best guess
$params['attachments'][] = [
        'filepath' => '<path to a valid file>',
];

notify_user($to_guid, $from_guid, $subject, $body, $params);

Page ownership¶

One recurring task of any plugin will be to determine the page ownership in order to decide which actions are allowed or not. Elgg has a number of functions related to page ownership and also offers plugin developers flexibility by letting the plugin handle page ownership requests as well. Determining the owner of a page can be determined with elgg_get_page_owner_guid(), which will return the GUID of the owner. Alternatively, elgg_get_page_owner_entity() will retrieve the whole page owner entity. If the page already knows who the page owner is, but the system doesn’t, the page can set the page owner by passing the GUID to elgg_set_page_owner_guid($guid).

Bemerkung

The page owner entity can be any ElggEntity. If you wish to only apply some setting in case of a user or a group make sure you check that you have the correct entity.

Custom page owner handlers¶

Plugin developers can create page owner handlers, which could be necessary in certain cases, for example when integrating third party functionality. The handler will be a function which will need to get registered with elgg_register_plugin_hook_handler('page_owner', 'system', 'your_page_owner_function_name'); . The handler will only need to return a value (an integer GUID) when it knows for certain who the page owner is.

By default, the system uses default_page_owner_handler() to determine the page_owner from the following elements:

The username URL parameter
The owner_guid URL parameter
The URL path

It then passes off to any page owner handlers defined using the plugin hook. If no page owner can be determined, the page owner is set to 0, which is the same as the logged out user.

Permissions Check¶

Warnung

As stated in the page, this method works only for granting write access to entities. You cannot use this method to retrieve or view entities for which the user does not have read access.

Elgg provides a mechanism of overriding write permissions check through the permissions_check plugin hook . This is useful for allowing plugin write to all accessible entities regardless of access settings. Entities that are hidden, however, will still be unavailable to the plugin.

Hooking permissions_check¶

In your plugin, you must register the plugin hook for permissions_check.

elgg_register_plugin_hook_handler('permissions_check', 'all', 'myplugin_permissions_check');

The override function¶

Now create the function that will be called by the permissions check hook. In this function we determine if the entity (in parameters) has write access. Since it is important to keep Elgg secure, write access should be given only after checking a variety of situations including page context, logged in user, etc. Note that this function can return 3 values: true if the entity has write access, false if the entity does not, and null if this plugin doesn’t care and the security system should consult other plugins.

function myplugin_permissions_check($hook_name, $entity_type, $return_value, $parameters) {
   $has_access = determine_access_somehow();

   if ($has_access === true) {
      return true;
   } else if ($has_access === false) {
      return false;
   }

   return null;
}

Full Example¶

This is a full example using the context to determine if the entity has write access.

<?php

function myaccess_init() {
   // Register cron hook
   if (!elgg_get_plugin_setting('period', 'myaccess')) {
      elgg_set_plugin_setting('period', 'fiveminute', 'myaccess');
   }

   // override permissions for the myaccess context
   elgg_register_plugin_hook_handler('permissions_check', 'all', 'myaccess_permissions_check');

   elgg_register_plugin_hook_handler('cron', elgg_get_plugin_setting('period', 'myaccess'), 'myaccess_cron');
}

/**
 * Hook for cron event.
 */
function myaccess_cron($event, $object_type, $object) {

   elgg_push_context('myaccess_cron');

   // returns all entities regardless of access permissions.
   // will NOT return hidden entities.
   $entities = get_entities();

   elgg_pop_context();
}

/**
 * Overrides default permissions for the myaccess context
 */
function myaccess_permissions_check($hook_name, $entity_type, $return_value, $parameters) {
   if (elgg_in_context('myaccess_cron')) {
      return true;
   }

   return null;
}

// Initialise plugin
register_elgg_event_handler('init', 'system', 'myaccess_init');
?>

Plugins¶

Plugins must provide a manifest.xml file in the plugin root in order to be recognized by Elgg.

Contents

elgg-plugin.php
Bootstrap class
start.php
elgg-services.php
manifest.xml
composer.json
Tests
Related

elgg-plugin.php ¶

elgg-plugin.php is a static plugin configuration file. It is read by Elgg to configure various services, and must return an array if present. It should not be included by plugins and is not guaranteed to run at any particular time. Besides magic constants like __DIR__, its return value should not change. The currently supported sections are:

bootstrap - defines a class used to bootstrap the plugin

entities - defines entity types and classes, and optionally registers them for search

actions - eliminates the need for calling elgg_register_action()

routes - eliminates the need for calling elgg_register_route()

settings - eliminates the need for setting default values on each call to elgg_get_plugin_setting()

user_settings - eliminates the need for setting default values on each call to elgg_get_plugin_user_setting()

views - allows plugins to alias vendor assets to a path within the Elgg’s view system

widgets - eliminates the need for calling elgg_register_widget_type()

events - eliminates the need for calling elgg_register_event_handler()

hooks - eliminates the need for calling elgg_register_plugin_hook_handler()

return [
        // Bootstrap must implement \Elgg\PluginBootstrapInterface
        'bootstrap' => MyPluginBootstrap::class,

        'entities' => [
                [
                        // Register a new object subtype and tell Elgg to use a specific class to instantiate it
                        'type' => 'object',
                        'subtype' => 'my_object_subtype',
                        'class' => MyObjectClass::class,

                        // Register this subtype for search
                        'searchable' => true,
                ],
        ],

        'actions' => [
                // Registers an action
                // By default, action is registered with 'logged_in' access
                // By default, Elgg will look for file in plugin's actions/ directory: actions/my_plugin/action.php
                'my_plugin/action/default' => [],

                'my_plugin/action/custom_access' => [
                        'access' => 'public', // supports 'public', 'logged_in', 'admin'
                ],

                // you can use action controllers instead of action files by setting the controller parameters
                // controller must be a callable that receives \Elgg\Request as the first and only argument
                // in example below, MyActionController::__invoke(\Elgg\Request $request) will be called
                'my_plugin/action/controller' => [
                        'controller' => MyActionController::class,
                ],
        ],

        'routes' => [
                // routes can be associated with resource views or controllers
                'collection:object:my_object_subtype:all' => [
                        'path' => '/my_stuff/all',
                        'resource' => 'my_stuff/all', // view file is in resources/my_stuff/all
                ],

                // similar to actions, routes can be associated with a callable controller that receives an instance of \Elgg\Request
                'collection:object:my_object_subtype:json' => [
                        'path' => '/my_stuff/json',
                        'controller' => JsonDumpController::class,
                ],

                // route definitions support other parameters, such as 'middleware', 'requirements', 'defaults'
                // see elgg_register_route() for all options
        ],

        'widgets' => [
                // register a new widget
                // corresponds to a view in widgets/my_stuff/content
                'my_stuff' => [
                        'description' => elgg_echo('widgets:my_stuff'),
                        'context' => ['profile', 'dashboard'],
                ],
        ],

        'settings' => [
                'plugin_setting_name' => 'plugin_setting_value',
        ],

        'user_settings' => [
                'user_setting_name' => 'user_setting_value',
        ],

        'views' => [
                'default' => [
                        'cool_lib/' => __DIR__ . '/vendors/cool_lib/dist/',
                ],
        ],

        'hooks' => [
                'register' => [
                        'menu:owner_block' => [
                                'blog_owner_block_menu' => [
                                        'priority' => 700,
                                ],
                        ],
                ],
                'likes:is_likable' => [
                        'object:blog' => [
                                'Elgg\Values::getTrue' => [],
                        ],
                ],
                'usersettings:save' => [
                        'user' => [
                                '_elgg_save_notification_user_settings' => ['unregister' => true],
                        ],
                ],
        ],

        'events' => [
                'delete' => [
                        'object' => [
                                'file_handle_object_delete' => [
                                        'priority' => 999,
                                ],
                        ],
                ],
                'create' => [
                        'relationship' => [
                                '_elgg_send_friend_notification' => [],
                        ],
                ],
                'log' => [
                        'systemlog' => [
                                'system_log_default_logger' => ['unregister' => true],
                        ],
                ],
        ],
];

Bootstrap class ¶

As of Elgg 3.0 the recommended way to bootstrap you plugin is to use a bootstrap class. This class must implement the \Elgg\PluginBootstrapInterface interface. You can register you bootstrap class in the elgg-plugin.php.

The bootstrap interface defines several function to be implemented which are called during different events in the system booting process.

Siehe auch

For more information about the different functions defined in the \Elgg\PluginBootstrapInterface please read Plugin bootstrap

start.php ¶

The start.php file bootstraps plugin by registering event listeners and plugin hooks.

It is advised that plugins return an instance of Closure from the start.php instead of placing registrations in the root of the file. This allows for consistency in Application bootstrapping, especially for testing purposes.

function my_plugin_does_something_else() {
    // Some procedural code that you want to run before any events are fired
}

function my_plugin_init() {
    // Your plugin's initialization logic
}

function my_plugin_rewrite_hook() {
    // Path rewrite hook
}

return function() {
    my_plugin_do_something_else();
    elgg_register_event_handler('init', 'system', 'my_plugin_init');
    elgg_register_plugin_hook_handler('route:rewrite', 'proifle', 'my_plugin_rewrite_hook');
}

elgg-services.php ¶

Plugins can attach their services to Elgg’s public DI container by providing PHP-DI definitions in elgg-services.php in the root of the plugin directory.

This file must return an array of PHP-DI definitions. Services will by available via elgg().

return [
   PluginService::class => \DI\object()->constructor(\DI\get(DependencyService::class)),
];

Plugins can then use PHP-DI API to autowire and call the service:

$service = elgg()->get(PluginService::class);

See PHP-DI documentation for a comprehensive list of definition and invokation possibilities.

Syntax¶

Here’s a trivial example configuring view locations via the views key:

return [
        'views' => [
                'default' => [
                        'file/icon/' => __DIR__ . '/graphics/icons',
                ],
        ],
];

manifest.xml ¶

Elgg plugins are required to have a manifest.xml file in the root of a plugin.

The manifest.xml file includes information about the plugin itself, requirements to run the plugin, and optional information including where to display the plugin in the admin area and what APIs the plugin provides.

Syntax¶

The manifest file is a standard XML file in UTF-8. Everything is a child of the <plugin_manifest> element.

<?xml version="1.0" encoding="UTF-8" ?>
<plugin_manifest xmlns="http://www.elgg.org/plugin_manifest/1.8">

The manifest syntax is as follows:

<name>value</name>

Many elements can contain children attributes:

<parent_name>
        <child_name>value</child_name>
        <child_name_2>value_2</child_name_2>
</parent_name>

Required Elements¶

All plugins are required to define the following elements in their manifest files:

id - This has the name as the directory that the plugin uses.
name - The display name of the plugin.
author - The name of the author who wrote the plugin.
version - The version of the plugin.
description - A description of the what the plugin provides, its features, and other relevant information
requires - Each plugin must specify the release of Elgg it was developed for. See the plugin Dependencies page for more information.

Available Elements¶

In addition to the require elements above, the follow elements are available to use:

blurb - A short description of the plugin.
category - The category of the plugin. It is recommended to follow the Plugin coding guidelines and use one of the defined categories. There can be multiple entries.
conflicts - Specifies that the plugin conflicts with a certain system configuration.
copyright - The plugin’s copyright information.
license - The plugin’s license information.
provides - Specifies that this plugin provides the same functionality as another Elgg plugin or a PHP extension.
suggests - Parallels the requires system, but doesn’t affect if the plugin can be enabled. Used to suggest other plugins that interact or build on the plugin.
website - A link to the website for the plugin.

Siehe auch

Plugin Dependencies

Simple Example¶

This manifest file is the bare minimum a plugin must have.

<?xml version="1.0" encoding="UTF-8"?>
<plugin_manifest xmlns="http://www.elgg.org/plugin_manifest/1.8">
        <name>Example Manifest</name>
        <author>Elgg</author>
        <version>1.0</version>
        <description>This is a simple example of a manifest file. In this example, there are no dependencies, or additional information about the plugin.</description>

        <requires>
                <type>elgg_release</type>
                <version>1.9</version>
        </requires>
</plugin_manifest>

Advanced example¶

This example uses all of the available elements:

<?xml version="1.0" encoding="UTF-8"?>
<plugin_manifest xmlns="http://www.elgg.org/plugin_manifest/1.8">
        <name>Example Manifest</name>
        <author>Brett Profitt</author>
        <version>1.0</version>
        <blurb>This is an example manifest file.</blurb>
        <description>This is a simple example of a manifest file. In this example, there are many options used, including dependencies, and additional information about the plugin.</description>
        <website>http://www.elgg.org/</website>
        <copyright>(C) Brett Profitt 2014</copyright>
        <license>GNU Public License version 2</license>

        <category>3rd_party_integration</category>

        <requires>
                <type>elgg_release</type>
                <version>1.9.1</version>
        </requires>

        <provides>
                <type>plugin</type>
                <name>example_plugin</name>
                <version>1.5</version>
        </provides>

        <suggests>
                <type>plugin</type>
                <name>twitter</name>
                <version>1.0</version>
        </suggests>
</plugin_manifest>

composer.json ¶

Since Elgg supports being installed as a Composer dependency, having your plugins also support Composer makes for easier installation by site administrators. In order to make your plugin compatible with Composer you need to at least have a composer.json file in the root of your plugin.

Here is an example of a composer.json file:

{
        "name": "company/example_plugin",
        "description": "Some description of the plugin",
        "type": "elgg-plugin",
        "keywords": ["elgg", "plugin"],
        "license": "GPL-2.0-only",
        "support": {
                "source": "URL to your code repository",
                "issues": "URL to your issue tracker"
        },
        "require": {
                "composer/installers": "^1.0.8"
        },
        "conflict": {
                "elgg/elgg": "<3.0"
        }
}

Read more about the composer.json format on the Composer website.

Important parts in the composer.json file are:

name: the name of your plugin, keep this inline with the name of your plugin folder to ensure correct installation
type: this will tell Composer where to install your plugin, ALWAYS keep this as elgg-plugin
require: the composer/installers requirement is to make sure Composer knows where to install your plugin

As a suggestion, include a conflict rule with any Elgg version below your mininal required version, this will help prevent the accidental installation of your plugin on an incompatible Elgg version.

After adding a composer.json file to your plugin project, you need to register your project on Packagist in order for other people to be able to install your plugin.

Tests ¶

It’s encouraged to create PHPUnit test for your plugin. All tests should be located in tests/phpunit/unit for unit tests and tests/phpunit/integration for integration tests.

An easy example of adding test is the ViewStackTest, this will test that the views in your plugin are registered correctly and have no syntax errors. To add this test create a file ViewStackTest.php in the folder tests/phpunit/unit/<YourNameSpace>/<YourPluginName>/ with the content:

namespace <YourNameSpace>\<YourPluginName>;

/**
 * @group ViewsService
 */
class ViewStackTest extends \Elgg\Plugins\ViewStackTest {

}

Bemerkung

If you wish to see a better example, look in any of the Elgg core plugins.

Siehe auch

Writing tests

River¶

Elgg natively supports the „river“, an activity stream containing descriptions of activities performed by site members. This page gives an overview of adding events to the river in an Elgg plugin.

Pushing river items¶

Items are pushed to the activity river through a function call, which you must include in your plugins for the items to appear.

Here we add a river item telling that a user has created a new blog post:

<?php

elgg_create_river_item([
        'view' => 'river/object/blog/create',
        'action_type' => 'create',
        'subject_guid' => $blog->owner_guid,
        'object_guid' => $blog->getGUID(),
]);

All available parameters:

view => STR The view that will handle the river item (must exist)
action_type => STR An arbitrary string to define the action (e.g. ‚create‘, ‚update‘, ‚vote‘, ‚review‘, etc)
subject_guid => INT The GUID of the entity doing the action (default: the logged in user guid)
object_guid => INT The GUID of the entity being acted upon
target_guid => INT The GUID of the the object entity’s container (optional)
access_id => INT The access ID of the river item (default: same as the object)
posted => INT The UNIX epoch timestamp of the river item (default: now)
annotation_id => INT The annotation ID associated with this river entry (optional)

When an item is deleted or changed, the river item will be updated automatically.

River views¶

As of Elgg 3.0 the view parameter is no longer required. A fallback logic has been created to check a series of views for you:

/river/{$type}/{$subtype}/{$action_type}: eg. river/object/blog/create only the create action will come to this view
river/{$type}/{$subtype}/default: eg. river/object/blog/default all river activity for object blog will come here
river/{$type}/{$action_type}: eg. river/object/create all create actions for object will come here
river/{$type}/default: eg. river/object/default all actions for all object will come here
river/elements/layout: ultimate fall back view, this should always be called in any of the river views to make a consistent layout

Both type and subtype are based on the type and subtype of the object_guid for which the river item was created.

Summary¶

If no summary parameter is provided to the river/elements/layout the view will try to create it for you. The basic result will be a text with the text Somebody did something on Object, where Somebody is based on subject_guid and Object is based on object_guid. For both Somebody and Object links will be created. These links are passed to a series of language keys so you can create a meaningfull summary.

The language keys are:

river:{$type}:{$subtype}:{$action_type}: eg. river:object:blog:create
river:{$type}:{$subtype}:default: eg. river:object:blog:default
river:{$type}:{$action_type}: eg. river:object:create
river:{$type}:default: eg. river:object:default

Custom river view¶

If you wish to add some more information to the river view, like an attachment (image, YouTube embed, etc), you must specify the view when creating the river item. This view MUST exist.

We recommend /river/{type}/{subtype}/{action}, where:

{type} is the entity type of the content we’re interested in (object for objects, user for users, etc)
{subtype} is the entity subtype of the content we’re interested in (blog for blogs, photo_album for albums, etc)
{action} is the action that took place (create, update, etc)

River item information will be passed in an object called $vars['item'], which contains the following important parameters:

$vars['item']->subject_guid The GUID of the user performing the action
$vars['item']->object_guid The GUID of the entity being acted upon

Timestamps etc will be generated for you.

For example, the blog plugin uses the following code for its river view:

$item = elgg_extract('item', $vars);
if (!$item instanceof ElggRiverItem) {
        return;
}

$blog = $item->getObjectEntity();
if (!$blog instanceof ElggBlog) {
        return;
}

$vars['message'] = $blog->getExcerpt();

echo elgg_view('river/elements/layout', $vars);

Routing¶

Elgg has two mechanisms to respond to HTTP requests that don’t already go through the Actions and Simplecache systems.

URL Identifier and Segments¶

After removing the site URL, Elgg splits the URL path by / into an array. The first element, the identifier, is shifted off, and the remaining elements are called the segments. For example, if the site URL is http://example.com/elgg/, the URL http://example.com/elgg/blog/owner/jane?foo=123 produces:

Identifier: 'blog'. Segments: ['owner', 'jane']. (the query string parameters are available via get_input())

The site URL (home page) is a special case that produces an empty string identifier and an empty segments array.

Warnung

URL identifier/segments should be considered potentially dangerous user input. Elgg uses htmlspecialchars to escapes HTML entities in them.

Page Handling¶

Elgg offers a facility to manage your plugin pages via custom routes, enabling URLs like http://yoursite/my_plugin/section. You can register a new route using elgg_register_route(), or via routes config in elgg-plugin.php. Routes map to resource views, where you can render page contents.

// in your 'init', 'system' handler
elgg_register_route('my_plugin:section' [
        'path' => '/my_plugin/section/{guid}/{subsection?}',
        'resource' => 'my_plugin/section',
        'requirements' => [
                'guid' => '\d+',
                'subsection' => '\w+',
        ],
]);

// in my_plugin/views/default/resources/my_plugin/section.php
$guid = elgg_extract('guid', $vars);
$subsection = elgg_extract('subsection', $vars);

// render content

In the example above, we have registered a new route that is accessible via http://yoursite/my_plugin/section/<guid>/<subsection>. Whenever that route is accessed with a required guid segment and an optional subsection segment, the router will render the specified my_plugin/section resource view and pass the parameters extracted from the URL to your resource view with $vars.

Routes names¶

Route names can then be used to generate a URL:

$url = elgg_generate_url('my_plugin:section', [
        'guid' => $entity->guid,
        'subsection' => 'assets',
]);

The route names are unique across all plugins and core, so another plugin can override the route by registering different parameters to the same route name.

Route names follow a certain convention and in certain cases will be used to automatically resolve URLs, e.g. to display an entity.

The following conventions are used in core and recommended for plugins:

view:<entity_type>:<entity_subtype>

Maps to the entity profile page, e.g. view:user:user or view:object:blog The path must contain a guid, or username for users

edit:<entity_type>:<entity_subtype>

Maps to the form to edit the entity, e.g. edit:user:user or edit:object:blog The path must contain a guid, or username for users If you need to add subresources, use suffixes, e.g. edit:object:blog:images, keeping at least one subresource as a default without suffix.

add:<entity_type>:<entity_subtype>

Maps to the form to add a new entity of a given type, e.g. add:object:blog The path, as a rule, contains container_guid parameter

collection:<entity_type>:<entity_subtype>:<collection_type>

Maps to listing pages. Common route names used in core are, as follows:

collection:object:blog:all: list all blogs

collection:object:blog:owner: list blogs owned by a user with a given username

collection:object:blog:friends: list blogs owned by friends of the logged in user (or user with a given username)

collection:object:blog:group: list blogs in a group

default:<entity_type>:<entity_subtype>

Maps to the default page for a resource, e.g. the path /blog. Elgg happens to use the „all“ collection for these routes.

default:object:blog: handle the generic path /blog.

<entity_subtype> can be omitted from route names to register global routes applicable to all entities of a given type. URL generator will first try to generate a URL using the subtype, and will then fallback to a route name without a subtype. For example, user profiles are routed to the same resource view regardless of user subtype.

elgg_register_route('view:object:attachments', [
        'path' => '/attachments/{guid}',
        'resource' => 'attachments',
]);

elgg_register_route('view:object:blog:attachments', [
        'path' => '/blog/view/{guid}/attachments',
        'resource' => 'blog/attachments',
]);

$blog = get_entity($blog_guid);
$url = elgg_generate_entity_url($blog, 'view', 'attachments'); // /blog/view/$blog_guid/attachments

$other = get_entity($other_guid);
$url = elgg_generate_entity_url($other, 'view', 'attachments'); // /attachments/$other_guid

Route configuration¶

Segments can be defined using wildcards, e.g. profile/{username}, which will match all URLs that contain profile/ followed by and arbitrary username.

To make a segment optional you can add a ? (question mark) to the wildcard name, e.g. profile/{username}/{section?}. In this case the URL will be matched even if the section segment is not provided.

You can further constrain segments using regex requirements:

// elgg-plugin.php
return [
        'routes' => [
                'profile' => [
                        'path' => '/profile/{username}/{section?}',
                        'resource' => 'profile',
                        'requirements' => [
                                'username' => '[\p{L}\p{Nd}._-]+', // only allow valid usernames
                                'section' => '\w+', // can only contain alphanumeric characters
                        ],
                        'defaults' => [
                                'section' => 'index',
                        ],
                ],
        ]
];

By default, Elgg will set the following requirements for named URL segments:

$patterns = [
        'guid' => '\d+', // only digits
        'group_guid' => '\d+', // only digits
        'container_guid' => '\d+', // only digits
        'owner_guid' => '\d+', // only digits
        'username' => '[\p{L}\p{Nd}._-]+', // letters, digits, underscores, dashes
];

Plugin dependent routes¶

If a route requires a specific plugin to be active this can be configured in the route configuration.

// elgg-plugin.php
return [
        'routes' => [
                'collection:object:blog:friends' => [
                        'path' => '/blog/friends/{username?}/{lower?}/{upper?}',
                        'resource' => 'blog/friends',
                        'required_plugins' => [
                                'friends', // route only allowed when friends plugin is active
                        ],
                ],
        ]
];

Route middleware¶

Route middleware can be used to prevent access to a certain route, or to perform some business logic before the route is rendered. Middleware can be used, e.g. to implement a paywall, or to log analytics, or to set open graph metatags.

Elgg core implements several middleware handlers. The following middleware can be found in the namespace \Elgg\Router\Middleware:

Gatekeeper¶

This gatekeeper will prevent access by non-authenticated users.

AdminGatekeeper¶

This gatekeeper will prevent access by non-admin users.

LoggedOutGatekeeper¶

This gatekeeper will prevent access by authenticated users.

AjaxGatekeeper¶

This gatekeeper will prevent access with non-xhr requests.

PageOwnerCanEditGatekeeper¶

This gatekeeper will prevent access if there is a pageowner detected and the pageowner can’t be editted.

GroupPageOwnerCanEditGatekeeper¶

This gatekeeper extends the PageOwnerCanEditGatekeeper but also requires the pageowner to be a ElggGroup entity.

UserPageOwnerCanEditGatekeeper¶

This gatekeeper extends the PageOwnerCanEditGatekeeper but also requires the pageowner to be an ElggUser entity.

CsrfFirewall¶

This middleware will prevent access without the correct CSRF tokens. This middleware will automatically be applied to actions.

ActionMiddleware¶

This middleware will provide action related logic. This middleware will automatically be applied to actions.

SignedRequestGatekeeper¶

This gatekeeper will prevent access if the url has been tampered with. A secure URL can be generated using the elgg_http_get_signed_url function.

UpgradeGatekeeper¶

This gatekeeper will prevent access if the upgrade URL is secured and the URL is invalid.

WalledGarden¶

This middleware will prevent access to a route if the site is configured for authenticated users only and there is no authenticated user logged in. This middleware is automatically enabled for all routes. You can disable the walled garden gatekeeper with a route config option.

Custom Middleware¶

Middleware handlers can be set to any callable that receives an instance of \Elgg\Request: The handler should throw an instance of HttpException to prevent route access. The handler can return an instance of \Elgg\Http\ResponseBuilder to prevent further implementation of the routing sequence (a redirect response can be returned to re-route the request).

class MyMiddleware {

        public function __invoke(\Elgg\Request $request) {
                $entity = $request->getEntityParam();
                if ($entity) {
                        // do stuff
                } else {
                        throw new EntityNotFoundException();
                }
        }
}

elgg_register_route('myroute', [
        'path' => '/myroute/{guid?}',
        'resource' => 'myroute',
        'middleware' => [
                \Elgg\Router\Middleware\Gatekeeper::class,
                MyMiddleware::class,
        ]
]);

Route controllers¶

In certain cases, using resource views is not appropriate. In these cases you can use a controller - any callable that receives an instance of \Elgg\Request:

class MyController {

        public function handleFoo(\Elgg\Request $request) {
                elgg_set_http_header('Content-Type: application/json');
                $data = [
                        'entity' => $request->getEntityParam(),
                ];
                return elgg_ok_response($data);
        }

}

elgg_register_route('myroute', [
        'path' => '/myroute/{guid?}',
        'controller' => [MyController::class, 'handleFoo'],
]);

The `route:rewrite` Plugin Hook¶

For URL rewriting, the route:rewrite hook (with similar arguments as route) is triggered very early, and allows modifying the request URL path (relative to the Elgg site).

Here we rewrite requests for news/* to blog/*:

function myplugin_rewrite_handler($hook, $type, $value, $params) {
    $value['identifier'] = 'blog';
    return $value;
}

elgg_register_plugin_hook_handler('route:rewrite', 'news', 'myplugin_rewrite_handler');

Warnung

The hook must be registered directly in your plugin start.php (the [init, system] event is too late).

Routing overview¶

For regular pages, Elgg’s program flow is something like this:

A user requests http://example.com/news/owner/jane.
Plugins are initialized.
Elgg parses the URL to identifier news and segments ['owner', 'jane'].
Elgg triggers the plugin hook route:rewrite, news (see above).
Elgg triggers the plugin hook route, blog (was rewritten in the rewrite hook).
Elgg finds a registered route that matches the final route path, and renders a resource view associated with it. It calls elgg_view_resource('blog/owner', $vars) where $vars contains the username.
The resources/blog/owner view gets the username via $vars['username'], and uses many other views and formatting functions like elgg_view_layout() and elgg_view_page() to create the entire HTML page.
PHP invokes Elgg’s shutdown sequence.
The user receives a fully rendered page.

Elgg’s coding standards suggest a particular URL layout, but there is no syntax enforced.

Search¶

Contents

Entity search
Search fields
Searchable types
Custom search types
Autocomplete and livesearch endpoint

Entity search ¶

Elgg core provides flexible elgg_search(), which prepares custom search clauses and utilizes elgg_get_entities() to fetch the results.

In addition to all parameters accepted by elgg_get_entities(), elgg_search() accepts the following:

query Search query

fields An array of names by property type to search in (see example below)

sort An array containing sorting options, including property, property_type and direction

type Entity type to search

subtype Optional entity subtype to search

search_type Custom search type (required if no type is provided)

partial_match Allow partial matches

By default partial matches are allowed, meaning that elgg will be matched when searching for el Exact matches may be helpful when you want to match tag values, e.g. when you want to find all objects that are red and not darkred

tokenize Break down search query into tokens

By default search queries are tokenized, meaning that we will match elgg has been released when searching for elgg released

// List all users who list United States as their address or mention it in their description
$options = [
    'type' => 'user',
    'query' => 'us',
    'fields' => [
        'metadata' => ['description'],
        'annotations' => ['location'],
    ],
    'sort' => [
        'property' => 'zipcode',
        'property_type' => 'annotation',
        'direction' => 'asc',
    ]
];

echo elgg_list_entities($options, 'elgg_search');

Search fields ¶

You can customize search fields for each entity type/subtype, using search:fields hook:

// Let's remove search in location and add address field instead
elgg_register_plugin_hook_handler('search:fields', 'user', 'my_plugin_search_user_fields');

function my_plugin_search_user_fields(\Elgg\Hook $hook) {
    $fields = $hook->getValue();
    $location_key = array_search('location', $fields['annotations']);
    if ($location_key) {
        unset($fields[$location_key]['annotations']);
    }

    $fields['metadata'][] = 'address';

    return $fields;
}

Searchable types ¶

To register an entity type for search, use elgg_register_entity_type(), or do so when defining an entity type in elgg-plugin.php. To combine search results or filter how search results are presented in the search plugin, use 'search:config', 'type_subtype_pairs' hook.

// Let's add places and place reviews as public facing entities
elgg_register_entity_type('object', 'place');
elgg_register_entity_type('object', 'place_review');

// Now let's include place reviews in the search results for places
elgg_register_plugin_hook_handler('search:options', 'object:place', 'my_plugin_place_search_options');
elgg_register_plugin_hook_handler('search:config', 'type_subtype_pairs', 'my_plugin_place_search_config');

// Add place review to search options as a subtype
function my_plugin_place_search_options($hook, $type, $value, $params) {

    if (empty($params) || !is_array($params)) {
        return;
    }

    if (isset($params['subtypes'])) {
        $subtypes = (array) $params['subtypes'];
    } else {
        $subtypes = (array) elgg_extract('subtype', $params);
    }

    if (!in_array('place', $subtypes)) {
        return;
    }

    unset($params["subtype"]);

    $subtypes[] = 'place_review';
    $params['subtypes'] = $subtypes;

    return $params;
}

// Remove place reviews as a separate entry in search sections
function my_plugin_place_search_config(\Elgg\Hook $hook) {

    $types = $hook->getValue();

    if (empty($types['object'])) {
        return;
    }

    foreach ($types['object'] as $key => $subtype) {
        if ($subtype == 'place_review') {
            unset($types['object'][$key]);
        }
    }

    return $types;
}

Custom search types ¶

Elgg core only supports entity search. You can implement custom searches, e.g. using search query as a location and listing entities by proximity to that location.

// Let's added proximity search type
elgg_register_plugin_hook_handler('search:config', 'search_types', function (\Elgg\Hook $hook) {
    $search_types = $hook->getValue();
    $search_types[] = 'promimity';

    return $search_types;
});

// Let's add search options that will look for entities that have geo coordinates and order them by proximity to the query location
elgg_register_plugin_hook_handler('search:options', 'proximity', function (\Elgg\Hook $hook) {

    $query = $hook->getParam('query');
    $options = $hook->getValue();

    // Let's presume we have a geocoding API
    $coords = geocode($query);

    // We are not using standard 'selects' options here, because counting queries do not use custom selects
    $options['wheres']['proximity'] = function (QueryBuilder $qb, $alias) use ($lat, $long) {
        $dblat = $qb->joinMetadataTable($alias, 'guid', 'geo:lat');
        $dblong = $qb->joinMetadataTable($alias, 'guid', 'geo:long');

        $qb->addSelect("(((acos(sin(($lat*pi()/180))
                    *sin(($dblat.value*pi()/180)) + cos(($lat*pi()/180))
                    *cos(($dblat.value*pi()/180))
                    *cos((($long-$dblong.value)*pi()/180)))))*180/pi())
                    *60*1.1515*1.60934
                    AS proximity");

        $qb->orderBy('proximity', 'asc');

        return $qb->merge([
            $qb->compare("$dblat.value", 'is not null'),
            $qb->compare("$dblong.value", 'is not null'),
        ]);
    };

    return $options;
});

Autocomplete and livesearch endpoint ¶

Core provides a JSON endpoint for searching users and groups. These endpoints are used by input/autocomplete and input/userpicker views.

// Get JSON results of a group search for 'class'
$json = file_get_contents('http://example.com/livesearch/groups?view=json&q=class');

You can add custom search types, by adding a corresponding resource view:

// Let's add an endpoint that will search for users that are not members of a group
// and render a userpicker for our invite form
echo elgg_view('input/userpicker', [
    'handler' => 'livesearch/non_members',
    'options' => [
        // this will be sent as URL query elements
        'group_guid' => $group_guid,
    ],
]);

// To enable /livesearch/non_members endpoint, we need to add a view
// in /views/json/resources/livesearch/non_members.php

$limit = get_input('limit', elgg_get_config('default_limit'));
$query = get_input('term', get_input('q'));
$input_name = get_input('name');

// We have passed this value to our input view, and we want to make sure
// external scripts are not using it to mine data on group members
// so let's validate the HMAC that was generated by the userpicker input
$group_guid = (int) get_input('group_guid');

$data = [
    'group_guid' => $group_guid,
];

// let's sort by key, in case we have more elements
ksort($data);

$hmac = elgg_build_hmac($data);
if (!$hmac->matchesToken(get_input('mac'))) {
     // request does not originate from our input view
     forward('', '403');
}

elgg_set_http_header("Content-Type: application/json;charset=utf-8");

$options = [
    'query' => $query,
    'type' => 'user',
    'limit' => $limit,
    'sort' => 'name',
    'order' => 'ASC',
    'fields' => [
        'metadata' => ['name', 'username'],
    ],
    'item_view' => 'search/entity',
    'input_name' => $input_name,
    'wheres' => function (QueryBuilder $qb) use ($group_guid) {
        $subquery = $qb->subquery('entity_relationships', 'er');
        $subquery->select('1')
            ->where($qb->compare('er.guid_one', '=', 'e.guid'))
            ->andWhere($qb->compare('er.relationship', '=', 'member', ELGG_VALUE_STRING))
            ->andWhere($qb->compare('er.guid_two', '=', $group_guid, ELGG_VALUE_INTEGER));

        return "NOT EXISTS ({$subquery->getSQL()})";
    }
];

echo elgg_list_entities($options, 'elgg_search');

Services¶

Elgg uses the Elgg\Application class to load and bootstrap Elgg. In future releases this class will offer a set of service objects for plugins to use.

Bemerkung

If you have a useful idea, you can add a new service!

Menus¶

elgg()->menus provides low-level methods for constructing menus. In general, menus should be passed to elgg_view_menu for rendering instead of manual rendering.

Plugin settings¶

You need to perform some extra steps if your plugin needs settings to be saved and controlled via the administration panel:

Create a file in your plugin’s default view folder called plugins/your_plugin/settings.php, where your_plugin is the name of your plugin’s directory in the mod hierarchy
Fill this file with the form elements you want to display together with internationalised text labels
Set the name attribute in your form components to params[`varname`] where varname is the name of the variable. These will be saved as private settings attached to a plugin entity. So, if your variable is called params[myparameter] your plugin (which is also passed to this view as $vars['entity']) will be called $vars['entity']->myparameter

An example settings.php would look like:

<p>
   <?php echo elgg_echo('myplugin:settings:limit'); ?>

   <select name="params[limit]">
      <option value="5" <?php if ($vars['entity']->limit == 5) echo " selected=\"yes\" "; ?>>5</option>
      <option value="8" <?php if ((!$vars['entity']->limit) || ($vars['entity']->limit == 8)) echo " selected=\"yes\" "; ?>>8</option>
      <option value="12" <?php if ($vars['entity']->limit == 12) echo " selected=\"yes\" "; ?>>12</option>
      <option value="15" <?php if ($vars['entity']->limit == 15) echo " selected=\"yes\" "; ?>>15</option>
   </select>
</p>

Bemerkung

You don’t need to add a save button or the form, this will be handled by the framework.

Bemerkung

You cannot use form components that send no value when „off.“ These include radio inputs and check boxes.

If your plugin settings require a cache flush you can add a (hidden) input on the form with the name ‚flush_cache‘ and value ‚1‘

elgg_view_field([
        '#type' => 'hidden',
        'name' => 'flush_cache',
        'value' => 1,
]);

User settings¶

Your plugin might need to store per user settings too, and you would like to have your plugin’s options to appear in the user’s settings page. This is also easy to do and follows the same pattern as setting up the global plugin configuration explained earlier. The only difference is that instead of using a settings file you will use usersettings. So, the path to the user edit view for your plugin would be plugins/your_plugin/usersettings.php.

Bemerkung

The title of the usersettings form will default to the plugin name. If you want to change this, add a translation for plugin_id:usersettings:title.

Retrieving settings in your code¶

To retrieve settings from your code use:

$setting = elgg_get_plugin_setting($name, $plugin_id);

or for user settings

$user_setting = elgg_get_plugin_user_setting($name, $user_guid, $plugin_id);

where:

$name Is the value you want to retrieve
$user_guid Is the user you want to retrieve these for (defaults to the currently logged in user)
$plugin_name Is the name of the plugin (detected if run from within a plugin)

Setting values while in code¶

Values may also be set from within your plugin code, to do this use one of the following functions:

elgg_set_plugin_setting($name, $value, $plugin_id);

or

elgg_set_plugin_user_setting($name, $value, $user_guid, $plugin_id);

Warnung

The $plugin_id needs to be provided when setting plugin (user)settings.

Default plugin (user) settings¶

If a plugin or a user not have a setting stored in the database, you sometimes have the need for a certain default value. You can pass this when using the getter functions.

$user_setting = elgg_get_plugin_user_setting($name, $user_guid, $plugin_id, $default);

$plugin_setting = elgg_get_plugin_setting($name, $plugin_id, $default);

Alternatively you can also provide default plugin and user settings in the elgg-plugin.php file.

<?php

return [
        'settings' => [
            'key' => 'value',
        ],
        'user_settings' => [
            'key' => 'value',
        ],
];

Themes¶

Customize the look and feel of Elgg.

A theme is a type of plugin that overrides display aspects of Elgg.

This guide assumes you are familiar with:

Contents

Theming Principles and Best Practices
Create your plugin
Customize the CSS
Tools
Customizing the front page

Theming Principles and Best Practices ¶

No third-party CSS frameworks: Elgg does not use a CSS framework, because such frameworks lock users into a specific HTML markup, which in the end makes it much harder for plugins to collaborate on the appearance. What’s is-primary in one theme, might be something else in the other. Having no framework allows plugins to alter appearance using pure css, without having to overwrite views and append framework-specific selectors to HTML markup elements.

/* BAD */
<div class="box has-shadow is-inline">
        This is bad, because if the plugin wants to change the styling, it will have to either write really specific css
        clearing all the attached styles, or replace the view entirely just to modify the markup
</div>

/* GOOD */
<div class="box-role">
        This is good, because a plugin can just simply add .box-role rule
</div>
<style>
        .box-role {
         padding: 1rem;
         display: inline-block;
         box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
        }
</style>

8-point grid system: Elgg uses an 8-point grid system <https://builttoadapt.io/intro-to-the-8-point-grid-system-d2573cde8632>, so sizing of elements, their padding, margins etc is done in increments and fractions of 8px. Because our default font-size is 16px, we use fractions of rem, so 0.5rem = 8px. 8-point grid system makes it a lot easier for developers to collaborate on styling elements: we no longer have to think if the padding should be 5px or 6px.

/* BAD */
.menu > li {
        margin: 2px 2px 2px 0;
}

.menu > li > a {
        padding: 3px 5px;
}

/* GOOD */
.menu > li > a {
        padding: 0.25rem 0.5rem;
}

Mobile first: We write mobile-first CSS. We use two breakpoints: 50rem and 80rem (800px and 1280px at 16px/rem).

/* BAD: mobile defined in media blocks, different display types */

.menu > li {
        display: inline-block;
}
@media screen and (max-width: 820px) {
        .menu > li {
                display: block;
                width: 100%;
        }
}

/* GOOD: mobile by default. Media blocks style larger viewports. */

.menu {
        display: flex;
        flex-direction: column;
}
@media screen and (min-width: 50rem) {
        .menu {
                flex-direction: row;
        }
}

Flexbox driven: Flexbox provides simplicity in stacking elements into grids. Flexbox is used for everything from menus to layout elements. We avoid float and clearfix as they are hard to collaborate on and create lots of room for failure and distortion.

/* BAD */
.heading:after {
        visibility: hidden;
        height: 0;
        clear: both;
        content: " ";
}
.heading > h2 {
        float: left;
}
.heading > .controls {
        float: right;
}

/* GOOD */
.heading {
        display: flex;
        justify-content: flex-end;
}
.heading > h2 {
        order: 1;
        margin-right: auto;
}
.heading > .controls {
        order: 2;
}

Symmetrical: We maintain symmetry.

/* BAD */
.row .column:first-child {
        margin-right: 10px;
}

/* GOOD */
.row {
        margin: 0 -0.5rem;
}
.row .column {
        margin: 0.5rem;
}

Simple color transitions: We maintain 4 sets of colors for text, background and border: soft, mild, strong and highlight. When transitioning to hover or active state, we go one level up, e.g. from soft to mild, or use highlight. When transition to inactive or disabled state, we go one level down.
Increase the click area: When working with nested anchors, we increase the click area of the anchor, rather than the parent

/* BAD */
.menu > li {
        margin: 5px;
        padding: 5px 10px;
}

/* GOOD */
.menu > li {
        margin: 0.5rem;
}
.menu > li > a {
        padding: 0.5rem 1rem;
}

No z-index 999999: z-indexes are incremented with a step of 1.
Wrap HTML siblings: We make sure that there are no orphaned strings within a parent and that siblings are wrapped in a way that they can be targeted by CSS.

/* BAD */
<label>
        Orphan
        <span>Sibling</span>
</label>

/* GOOD */
<label>
        <span>Sibling</span>
        <span>Sibling</span>
</label>

/* BAD */
<div>
        <h3>Title</h3>
        <p>Subtitle</p>
        <div class="right">This goes to the right</div>
</div>

/* GOOD */
<div>
        <div class="left">
         <h3>Title</h3>
         <p>Subtitle</p>
        </div>
        <div class="right">This goes to the right</div>
</div>

Create your plugin ¶

Create your plugin as described in the developer guide.

Create a new directory under mod/
Create a new start.php
Create a manifest.xml file describing your theme.

Customize the CSS ¶

The css is split into several files based on what aspects of the site you’re theming. This allows you to tackle them one at a time, giving you a chance to make real progress without getting overwhelmed.

Here is a list of the existing CSS views:

elements/buttons.css: Provides a way to style all the different kinds of buttons your site will use. There are 5 kinds of buttons that plugins will expect to be available: action, cancel, delete, submit, and special.

elements/chrome.css: This file has some miscellaneous look-and-feel classes.

elements/components.css: This file contains many “css objects” that are used all over the site: media block, list, gallery, table, owner block, system messages, river, tags, photo, and comments.

elements/forms.css: This file determines what your forms and input elements will look like.

elements/icons.css: Contains styles for the icons and avatars used on your site.

elements/layout.css: Determines what your page layout will look like: sidebars, page wrapper, main body, header, footer, etc.

elements/modules.css: Lots of content in Elgg is displayed in boxes with a title and a content body. We called these modules. There are a few kinds: info, aside, featured, dropdown, popup, widget. Widget styles are included in this file too, since they are a subset of modules.

elements/navigation.css: This file determines what all your menus will look like.

elements/typography.css: This file determines what the content and headings of your site will look like.

rtl.css: Custom rules for users viewing your site in a right-to-left language.

admin.css: A completely separate theme for the admin area (usually not overridden).

elgg.css: Compiles all the core elements/* files into one file (DO NOT OVERRIDE).

elements/core.css: Contains base styles for the more complicated “css objects”. If you find yourself wanting to override this, you probably need to report a bug to Elgg core instead (DO NOT OVERRIDE).

elements/reset.css: Contains a reset stylesheet that forces elements to have the same default

CSS variables ¶

Elgg uses CssCrush for preprocessing CSS files. This gives us the flexibility of using global CSS variables. Plugins should, wherever possible, use global CSS variables, and extend the core theme with their plugin variables, so they can be simply altered by other plugins.

To add or alter variables, use the vars:compiler, css hook. Note that you may need to flush the cache to see your changes in action.

For a list of default core variables, see engine/theme.php.

View extension ¶

There are two ways you can modify views:

The first way is to add extra stuff to an existing view via the extend view function from within your start.php’s initialization function.

For example, the following start.php will add mytheme/css to Elgg’s core css file:

<?php

        function mytheme_init() {
                elgg_extend_view('elgg.css', 'mytheme/css');
        }

        elgg_register_event_handler('init', 'system', 'mytheme_init');
?>

View overloading ¶

Plugins can have a view hierarchy, any file that exists here will replace any files in the existing core view hierarchy… so for example, if my plugin has a file:

/mod/myplugin/views/default/elements/typography.css

it will replace:

/views/default/elements/typography.css

But only when the plugin is active.

This gives you total control over the way Elgg looks and behaves. It gives you the option to either slightly modify or totally replace existing views.

Icons ¶

As of Elgg 2.0 the default Elgg icons come from the FontAwesome library. You can use any of these icons by calling:

elgg_view_icon('icon-name');

icon-name can be any of the FontAwesome icons without the fa--prefix.

By default you will get the solid styled variant of the icons. Postfixing the icon name with -solid, -regular or -light allows you to target a specific style. Be advised; the light styled variant is only available as a FontAwesome Pro licensed icon.

Tools ¶

We’ve provided you with some development tools to help you with theming: Turn on the “Developers” plugin and go to the “Theme Preview” page to start tracking your theme’s progress.

Customizing the front page ¶

The main Elgg index page runs a plugin hook called ‚index,system‘. If this returns true, it assumes that another front page has been drawn and doesn’t display the default page.

Therefore, you can override it by registering a function to the ‚index,system‘ plugin hook and then returning true from that function.

Here’s a quick overview:

Create your new plugin
In the start.php you will need something like the following:

<?php

function pluginname_init() {
        // Replace the default index page
        elgg_register_plugin_hook_handler('index', 'system', 'new_index');
}

function new_index() {
        if (!include_once(dirname(dirname(__FILE__)) . "/pluginname/pages/index.php"))
                return false;

        return true;
}

// register for the init, system event when our plugin start.php is loaded
elgg_register_event_handler('init', 'system', 'pluginname_init');
?>

Then, create an index page (/pluginname/pages/index.php) and use that

to put the content you would like on the front page of your Elgg site.

Writing a plugin upgrade¶

Every now and then there comes a time when a plugin needs to change the contents or the structure of the data it has stored either in the database or the dataroot.

The motivation for this may be that the data structure needs to be converted to more efficient or flexible structure. Or perhaps due to a bug the data items have been saved in an invalid way, and they needs to be converted to the correct format.

Migrations and convertions like this may take a long time if there is a lot of data to be processed. This is why Elgg provides the Elgg\Upgrade\Batch interface that can be used for implementing long-running upgrades.

Declaring a plugin upgrade¶

Plugin can communicate the need for an upgrade under the upgrades key in elgg-plugin.php file. Each value of the array must be the fully qualified name of an upgrade class that implements the Elgg\Upgrade\Batch interface.

Example from mod/blog/elgg-plugin.php file:

return [
        'upgrades' => [
                Blog\Upgrades\AccessLevelFix::class,
                Blog\Upgrades\DraftStatusUpgrade::class,
        ]
];

The class names in the example refer to the classes:

mod/blog/classes/Blog/Upgrades/AccessLevelFix
mod/blog/classes/Blog/Upgrades/DraftStatusUpgrade

Bemerkung

Elgg core upgrade classes can be declared in engine/lib/upgrades/async-upgrades.php.

The upgrade class¶

A class implementing the Elgg\Upgrade\Batch interface has a lot of freedom on how it wants to handle the actual processing of the data. It must however declare some constant variables and also take care of marking whether each processed item was upgraded successfully or not.

The basic structure of the class is the following:

<?php

namespace Blog\Upgrades;

use Elgg\Upgrade\Batch;
use Elgg\Upgrade\Result;

/**
 * Fixes invalid blog access values
 */
class AccessLevelFix implements Batch {

        /**
         * Version of the upgrade
         *
         * @return int
         */
        public function getVersion() {
                return 2016120300;
        }

        /**
         * Should the run() method receive an offset representing all processed items?
         *
         * @return bool
         */
        public function needsIncrementOffset() {
                return true;
        }

        /**
         * Should this upgrade be skipped?
         *
         * @return bool
         */
        public function shouldBeSkipped() {
                return false;
        }

        /**
         * The total number of items to process in the upgrade
         *
         * @return int
         */
        public function countItems() {
                // return count of all blogs
        }

        /**
         * Runs upgrade on a single batch of items
         *
         * @param Result $result Result of the batch (this must be returned)
         * @param int    $offset Number to skip when processing
         *
         * @return Result Instance of \Elgg\Upgrade\Result
         */
        public function run(Result $result, $offset) {
                // fix 50 blogs skipping the first $offset
        }
}

Warnung

Do not assume when your class will be instantiated or when/how often its public methods will be called.

Class methods¶

getVersion()¶

This must return an integer representing the date the upgrade was added. It consists of eight digits and is in format yyyymmddnn where:

yyyy is the year

mm is the month (with leading zero)

dd is the day (with leading zero)

nn is an incrementing number (starting from 00) that is used in case two separate upgrades have been added during the same day

shouldBeSkipped()¶

This should return false unless the upgrade won’t be needed.

Warnung

If true is returned the upgrade cannot be run later.

needsIncrementOffset()¶

If true, your run() method will receive as $offset the number of items aready processed. This is useful if you are only modifying data, and need to use the $offset in a function like elgg_get_entities() to know how many you’ve already handled.

If false, your run() method will receive as $offset the total number of failures. false should be used if your process deletes or moves data out of the way of the process. E.g. if you delete 50 objects on each run(), you don’t really need the $offset.

countItems()¶

Get the total number of items to process during the upgrade. If unknown, Batch::UNKNOWN_COUNT can be returned, but run() must manually mark the upgrade complete.

run()¶

This must perform a portion of the actual upgrade. And depending on how long it takes, it may be called multiple times during a single request.

It receives two arguments:

$result: An instance of Elgg\Upgrade\Result object

$offset: The offset where the next upgrade portion should start (or total number of failures)

For each item the method processes, it must call either:

$result->addSuccesses(): If the item was upgraded successfully

$result->addFailures(): If it failed to upgrade the item

Both methods default to one item, but you can optionally pass in the number of items.

Additionally it can set as many error messages as it sees necessary in case something goes wrong:

$result->addError("Error message goes here")

If countItems() returned Batch::UNKNOWN_COUNT, then at some point run() must call $result->markComplete() to finish the upgrade.

In most cases your run() method will want to pass the $offset parameter to one of the elgg_get_entities() functions:

/**
 * Process blog posts
 *
 * @param Result $result The batch result (will be modified and returned)
 * @param int    $offset Starting point of the batch
 * @return Result Instance of \Elgg\Upgrade\Result;
 */
public function run(Result $result, $offset) {
        $blogs = elgg_get_entitites([
                'type' => 'object'
                'subtype' => 'blog'
                'offset' => $offset,
        ]);

        foreach ($blogs as $blog) {
                if ($this->fixBlogPost($blog)) {
                        $result->addSuccesses();
                } else {
                        $result->addFailures();
                        $result->addError("Failed to fix the blog {$blog->guid}.");
                }
        }

        return $result;
}

Administration interface¶

Each upgrade implementing the Elgg\Upgrade\Batch interface gets listed in the admin panel after triggering the site upgrade from the Administration dashboard.

While running the upgrades Elgg provides:

Estimated duration of the upgrade

Count of processed items

Number of errors

Possible error messages

Views¶

Contents

Introduction ¶

Views are responsible for creating output. They handle everything from:

the layout of pages

chunks of presentation output (like a footer or a toolbar)

individual links and form inputs.

the images, js, and css needed by your web page

Using views ¶

At their most basic level, the default views are just PHP files with snippets of html:

<h1>Hello, World!</h1>

Assuming this view is located at /views/default/hello.php, we could output it like so:

echo elgg_view('hello');

For your convenience, Elgg comes with quite a lot of views by default. In order to keep things manageable, they are organized into subdirectories. Elgg handles this situation quite nicely. For example, our simple view might live in /views/default/hello/world.php, in which case it would be called like so:

echo elgg_view('hello/world');

The name of the view simply reflects the location of the view in the views directory.

Views as templates ¶

You can pass arbitrary data to a view via the $vars array. Our hello/world view might be modified to accept a variable like so:

<h1>Hello, <?= $vars['name']; ?>!</h1>

In this case, we can pass an arbitrary name parameter to the view like so:

echo elgg_view('hello/world', ['name' => 'World']);

which would produce the following output:

<h1>Hello, World!</h1>

Warnung

Views don’t do any kind of automatic output sanitization by default. You are responsible for doing the correct sanitization yourself to prevent XSS attacks and the like.

Views as cacheable assets ¶

As mentioned before, views can contain JS, CSS, or even images.

Asset views must meet certain requirements:

They must not take any $vars parameters

They must not change their output based on global state like

who is logged in

the time of day

They must contain a valid file extension

Bad: my/cool/template

Good: my/cool/template.html

For example, suppose you wanted to load some CSS on a page. You could define a view mystyles.css, which would look like so:

/* /views/default/mystyles.css */
.mystyles-foo {
  background: red;
}

Bemerkung

Leave off the trailing „.php“ from the filename and Elgg will automatically recognize the view as cacheable.

To get a URL to this file, you would use elgg_get_simplecache_url:

// Returns "https://mysite.com/.../289124335/default/mystyles.css
elgg_get_simplecache_url('mystyles.css');

Elgg automatically adds the magic numbers you see there for cache-busting and sets long-term expires headers on the returned file.

Warnung

Elgg may decide to change the location or structure of the returned URL in a future release for whatever reason, and the cache-busting numbers change every time you flush Elgg’s caches, so the exact URL is not stable by design.

With that in mind, here’s a couple anti-patterns to avoid:

Don’t rely on the exact structure/location of this URL

Don’t try to generate the URLs yourself

Don’t store the returned URLs in a database

On the page you want to load the css, call:

elgg_require_css('mystyles');

Views and third-party assets ¶

The best way to serve third-party assets is through views. However, instead of manually copy/pasting the assets into the right location in /views/*, you can map the assets into the views system via the "views" key in your plugin’s elgg-plugin.php config file.

The views value must be a 2 dimensional array. The first level maps a viewtype to a list of view mappings. The secondary lists map view names to file paths, either absolute or relative to the Elgg root directory.

If you check your assets into source control, point to them like this:

<?php // mod/example/elgg-plugin.php
return [
    // view mappings
    'views' => [
        // viewtype
        'default' => [
            // view => /path/from/filesystem/root
            'js/jquery-ui.js' => __DIR__ . '/bower_components/jquery-ui/jquery-ui.min.js',
        ],
    ],
];

To point to assets installed with composer, use install-root-relative paths by leaving off the leading slash:

<?php // mod/example/elgg-plugin.php
return [
    'views' => [
        'default' => [
            // view => path/from/install/root
            'js/jquery-ui.js' => 'vendor/bower-asset/jquery-ui/jquery-ui.min.js',
        ],
    ],
];

Elgg core uses this feature extensively, though the value is returned directly from /engine/views.php.

Bemerkung

You don’t have to use Bower, Composer Asset Plugin, or any other script for managing your plugin’s assets, but we highly recommend using a package manager of some kind because it makes upgrading so much easier.

Specifying additional views directories ¶

In elgg-plugin.php you can also specify directories to be scanned for views. Just provide a view name prefix ending with / and a directory path (like above).

<?php // mod/file/elgg-plugin.php
return [
    'views' => [
        'default' => [
            'file/icon/' => __DIR__ . '/graphics/icons',
        ],
    ],
];

With the above, files found within the icons folder will be interpreted as views. E.g. the view file/icon/general.gif will be created and mapped to mod/file/graphics/icons/general.gif.

Bemerkung

This is a fully recursive scan. All files found will be brought into the views system.

Multiple paths can share the same prefix, just give an array of paths:

<?php // mod/file/elgg-plugin.php
return [
    'views' => [
        'default' => [
            'file/icon/' => [
                __DIR__ . '/graphics/icons',
                __DIR__ . '/more_icons', // processed 2nd (may override)
            ],
        ],
    ],
];

Viewtypes ¶

You might be wondering: „Why /views/default/hello/world.php instead of just /views/hello/world.php?“.

The subdirectory under /views determines the viewtype of the views below it. A viewtype generally corresponds to the output format of the views.

The default viewtype is assumed to be HTML and other static assets necessary to render a responsive web page in a desktop or mobile browser, but it could also be:

RSS

ATOM

JSON

Mobile-optimized HTML

TV-optimized HTML

Any number of other data formats

You can force Elgg to use a particular viewtype to render the page by setting the view input variable like so: https://mysite.com/?view=rss.

You could also write a plugin to set this automatically using the elgg_set_viewtype() function. For example, your plugin might detect that the page was accessed with an iPhone’s browser string, and set the viewtype to iphone by calling:

elgg_set_viewtype('iphone');

The plugin would presumably also supply a set of views optimized for those devices.

Altering views via plugins ¶

Without modifying Elgg’s core, Elgg provides several ways to customize almost all output:

You can override a view, completely changing the file used to render it.
You can extend a view by prepending or appending the output of another view to it.
You can alter a view’s inputs by plugin hook.
You can alter a view’s output by plugin hook.

Overriding views ¶

Views in plugin directories always override views in the core directory; however, when plugins override the views of other plugins, later plugins take precedent.

For example, if we wanted to customize the hello/world view to use an h2 instead of an h1, we could create a file at /mod/example/views/default/hello/world.php like this:

<h2>Hello, <?= $vars['name']; ?></h2>

Bemerkung

When considering long-term maintenance, overriding views in the core and bundled plugins has a cost: Upgrades may bring changes in views, and if you have overridden them, you will not get those changes.

You may instead want to alter the input or the output of the view via plugin hooks.

Bemerkung

Elgg caches view locations. This means that you should disable the system cache while developing with views. When you install the changes to a production environment you must flush the caches.

Extending views ¶

There may be other situations in which you don’t want to override the whole view, you just want to prepend or append some more content to it. In Elgg this is called extending a view.

For example, instead of overriding the hello/world view, we could extend it like so:

elgg_extend_view('hello/world', 'hello/greeting');

If the contents of /views/default/hello/greeting.php is:

<h2>How are you today?</h2>

Then every time we call elgg_view('hello/world');, we’ll get:

<h1>Hello, World!</h1>
<h2>How are you today?</h2>

You can prepend views by passing a value to the 3rd parameter that is less than 500:

// appends 'hello/greeting' to every occurrence of 'hello/world'
elgg_extend_view('hello/world', 'hello/greeting');

// prepends 'hello/greeting' to every occurrence of 'hello/world'
elgg_extend_view('hello/world', 'hello/greeting', 450);

All view extensions should be registered in your plugin’s init,system event handler in start.php.

Altering view input ¶

It may be useful to alter a view’s $vars array before the view is rendered.

Before each view rendering the $vars array is filtered by the plugin hook ["view_vars", $view_name]. Each registered handler function is passed these arguments:

$hook - the string "view_vars"
$view_name - the view name being rendered (the first argument passed to elgg_view())
$returnvalue - the modified $vars array
$params - an array containing:
- vars - the original $vars array, unaltered
- view - the view name
- viewtype - The viewtype being rendered

Altering view input example¶

Here we’ll alter the default pagination limit for the comments view:

elgg_register_plugin_hook_handler('view_vars', 'page/elements/comments', 'myplugin_alter_comments_limit');

function myplugin_alter_comments_limit($hook, $type, $vars, $params) {
    // only 10 comments per page
    $vars['limit'] = elgg_extract('limit', $vars, 10);
    return $vars;
}

Altering view output ¶

Sometimes it is preferable to alter the output of a view instead of overriding it.

The output of each view is run through the plugin hook ["view", $view_name] before being returned by elgg_view(). Each registered handler function is passed these arguments:

$hook - the string "view"
$view_name - the view name being rendered (the first argument passed to elgg_view())
$result - the modified output of the view
$params - an array containing:
- viewtype - The viewtype being rendered

To alter the view output, the handler just needs to alter $returnvalue and return a new string.

Altering view output example¶

Here we’ll eliminate breadcrumbs that don’t have at least one link.

elgg_register_plugin_hook_handler('view', 'navigation/breadcrumbs', 'myplugin_alter_breadcrumb');

function myplugin_alter_breadcrumb($hook, $type, $returnvalue, $params) {
    // we only want to alter when viewtype is "default"
    if ($params['viewtype'] !== 'default') {
        return $returnvalue;
    }

    // output nothing if the content doesn't have a single link
    if (false === strpos($returnvalue, '<a ')) {
        return '';
    }

    // returning nothing means "don't alter the returnvalue"
}

Replacing view output completely ¶

You can pre-set the view output by setting $vars['__view_output']. The value will be returned as a string. View extensions will not be used and the view hook will not be triggered.

elgg_register_plugin_hook_handler('view_vars', 'navigation/breadcrumbs', 'myplugin_no_page_breadcrumbs');

function myplugin_no_page_breadcrumbs($hook, $type, $vars, $params) {
    if (elgg_in_context('pages')) {
        return ['__view_output' => ""];
    }
}

Bemerkung

For ease of use you can also use a already existing default hook callback to prevent output \Elgg\Values::preventViewOutput

Displaying entities ¶

If you don’t know what an entity is, check this page out first.

The following code will automatically display the entity in $entity:

echo elgg_view_entity($entity);

As you’ll know from the data model introduction, all entities have a type (object, site, user or group), and optionally a subtype (which could be anything - ‚blog‘, ‚forumpost‘, ‚banana‘).

elgg_view_entity will automatically look for a view called type/subtype; if there’s no subtype, it will look for type/type. Failing that, before it gives up completely it tries type/default.

RSS feeds in Elgg generally work by outputting the object/default view in the ‚rss‘ viewtype.

For example, the view to display a blog post might be object/blog. The view to display a user is user/default.

Full and partial entity views ¶

elgg_view_entity actually has a number of parameters, although only the very first one is required. The first three are:

$entity - The entity to display
$viewtype - The viewtype to display in (defaults to the one we’re currently in, but it can be forced - eg to display a snippet of RSS within an HTML page)
$full_view - Whether to display a full version of the entity. (Defaults to true.)

This last parameter is passed to the view as $vars['full_view']. It’s up to you what you do with it; the usual behaviour is to only display comments and similar information if this is set to true.

Listing entities ¶

This is then used in the provided listing functions. To automatically display a list of blog posts (see the full tutorial), you can call:

echo elgg_list_entities([
    'type' => 'object',
    'subtype' => 'blog',
]);

This function checks to see if there are any entities; if there are, it first displays the navigation/pagination view in order to display a way to move from page to page. It then repeatedly calls elgg_view_entity on each entity before returning the result.

Note that elgg_list_entities allows the URL to set its limit and offset options, so set those explicitly if you need particular values (e.g. if you’re not using it for pagination).

Elgg knows that it can automatically supply an RSS feed on pages that use elgg_list_entities. It initializes the ["head","page"] plugin hook (which is used by the header) in order to provide RSS autodiscovery, which is why you can see the orange RSS icon on those pages in some browsers.

Entity listings will default try to load entity owners and container owners. If you want to prevent this you can turn this off.

echo elgg_list_entities([
    'type' => 'object',
    'subtype' => 'blog',

    // disable owner preloading
    'preload_owners' => false,
]);

If you want to show a message when the list does not contain items to list, you can pass a no_results message or true for the default message. If you want even more controle over the no_results message you can also pass a Closure (an anonymous function).

echo elgg_list_entities([
    'type' => 'object',
    'subtype' => 'blog',

    'no_results' => elgg_echo('notfound'),
]);

Rendering a list with an alternate view ¶

You can define an alternative view to render list items using 'item_view' parameter.

In some cases, default entity views may be unsuitable for your needs. Using item_view allows you to customize the look, while preserving pagination, list’s HTML markup etc.

Consider these two examples:

echo elgg_list_entities([
    'type' => 'group',
    'relationship' => 'member',
    'relationship_guid' => elgg_get_logged_in_user_guid(),
    'inverse_relationship' => false,
    'full_view' => false,
]);

echo elgg_list_entities([
    'type' => 'group',
    'relationship' => 'invited',
    'relationship_guid' => (int) $user_guid,
    'inverse_relationship' => true,
    'item_view' => 'group/format/invitationrequest',
]);

In the first example, we are displaying a list of groups a user is a member of using the default group view. In the second example, we want to display a list of groups the user was invited to.

Since invitations are not entities, they do not have their own views and can not be listed using elgg_list_*. We are providing an alternative item view, that will use the group entity to display an invitation that contains a group name and buttons to access or reject the invitation.

Rendering a list as a table ¶

Since 2.3 you can render lists as tables. Set $options['list_type'] = 'table' and provide an array of TableColumn objects as $options['columns']. The service elgg()->table_columns provides several methods to create column objects based around existing views (like page/components/column/*), properties, or methods.

In this example, we list the latest my_plugin objects in a table of 3 columns: entity icon, the display name, and a friendly format of the time.

echo elgg_list_entities([
    'type' => 'object',
    'subtype' => 'my_plugin',

    'list_type' => 'table',
    'columns' => [
        elgg()->table_columns->icon(),
        elgg()->table_columns->getDisplayName(),
        elgg()->table_columns->time_created(null, [
            'format' => 'friendly',
        ]),
    ],
]);

See the Elgg\Views\TableColumn\ColumnFactory class for more details on how columns are specified and rendered. You can add or override methods of elgg()->table_columns in a variety of ways, based on views, properties/methods on the items, or given functions.

Icons ¶

Elgg has support for two kind of icons: generic icons to help with styling (eg. show delete icon) and Entity icons (eg. user avatar).

Generic icons ¶

As of Elgg 2.0 the generic icons are based on the FontAwesome library. You can get any of the supported icons by calling elgg_view_icon($icon_name, $vars); where:

$icon_name is the FontAwesome name (without fa-) for example user
$vars is optional, for example you can set an additional class

elgg_view_icon() calls the view output/icon with the given icon name and outputs all the correct classes to render the FontAwesome icon. If you wish to replace an icon with another icon you can write a view_vars, output/icon hook to replace the icon name with your replacement.

For backwards compatibility some older Elgg icon names are translated to a corresponding FontAwesome icon.

Entity icons ¶

To view an icon belowing to an Entity call elgg_view_entity_icon($entity, $size, $vars); where:

$entity is the ElggEntity you wish to show the icon for
$size is the requestes size. Default Elgg supports large, medium, small, tiny and topbar (master is also available, but don’t use it)
$vars in order to pass additional information to the icon view

elgg_view_entity_icon() calls a view in the order:

icon/<type>/<subtype>
icon/<type>/default
icon/default

So if you wish to customize the layout of the icon you can overrule the corresponding view.

An example of displaying a user avatar is

// get the user
$user = elgg_get_logged_in_user_entity();

// show the small icon
echo elgg_view_entity_icon($user, 'small');

// don't add the user_hover menu to the icon
echo elgg_view_entity_icon($user, 'small', [
        'use_hover' => false,
]);

Walled Garden¶

Elgg supports a „Walled Garden“ mode. In this mode, almost all pages are restricted to logged in users. This is useful for sites that don’t allow public registration.

Activating Walled Garden mode¶

To activate Walled Garden mode in Elgg, go to the Administration section. On the right sidebar menu, under the „Configure“ section, expand „Settings,“ then click on „Advanced.“

From the Advanced Settings page, find the option labelled „Restrict pages to logged-in users.“ Enable this option, then click „Save“ to switch your site into Walled Garden mode.

Exposing pages through Walled Gardens¶

Many plugins extend Elgg by adding pages. Walled Garden mode will prevent these pages from being viewed by logged out users. Elgg uses plugin hook to manage which pages are visible through the Walled Garden.

Plugin authors must register pages as public if they should be viewable through Walled Gardens:

by setting 'walled' => false in route configuration

by responding to the public_pages, walled_garden plugin hook. The returned value is an array of regexp expressions for public pages.

The following code shows how to expose http://example.org/my_plugin/public_page through a Walled Garden. This assumes the plugin has registered a route for my_plugin/public_page.

// Preferred way
elgg_register_route('my_plugin:public_page', [
    'path' => '/my_plugin/public_page',
    'resource' => 'my_plugin/public_page',
    'walled' => false,
]);

// Legacy approach
elgg_register_plugin_hook_handler('public_pages', 'walled_garden', 'my_plugin_walled_garden_public_pages');

function my_plugin_walled_garden_public_pages($hook, $type, $pages) {
   $pages[] = 'my_plugin/public_page';
   return $pages;
}

Web services¶

Build an HTTP API for your site.

Elgg provides a powerful framework for building web services. This allows developers to expose functionality to other web sites and desktop applications along with doing integrations with third-party web applications. While we call the API RESTful, it is actually a REST/RPC hybrid similar to the APIs provided by sites like Flickr and Twitter.

To create an API for your Elgg site, you need to do 4 things:

enable the web services plugin
expose methods
setup API authentication
setup user authentication

Additionally, you may want to control what types of authentication are available on your site. This will also be covered.

Contents

Security
Exposing methods
API authentication
- Key-based authentication
- Signature-based authentication
User authentication
Building out your API
Determining the authentication available
Related

Security ¶

It is crucial that the web services are consumed via secure protocols. Do not enable web services if your site is not served via HTTPs. This is especially important if you allow API key only authentication.

If you are using third-party tools that expose API methods, make sure to carry out a thorough security audit. You may want to make sure that API authentication is required for ALL methods, even if they require user authentication. Methods that do not require API authentication can be easily abused to spam your site.

Ensure that the validity of API keys is limited and provide mechanisms for your API clients to renew their keys.

Exposing methods ¶

The function to use to expose a method is elgg_ws_expose_function(). As an example, let’s assume you want to expose a function that echos text back to the calling application. The function could look like this

function my_echo($string) {
    return $string;
}

Since we are providing this function to allow developers to test their API clients, we will require neither API authentication nor user authentication. This call registers the function with the web services API framework:

elgg_ws_expose_function(
        "test.echo",
        "my_echo",
        [
                "string" => [
                        'type' => 'string',
                ]
        ],
        'A testing method which echos back a string',
        'GET',
        false,
        false
);

If you add this code to a plugin and then go to http://yoursite.com/services/api/rest/json/?method=system.api.list, you should now see your test.echo method listed as an API call. Further, to test the exposed method from a web browser, you could hit the url: http://yoursite.com/services/api/rest/json/?method=test.echo&string=testing and you should see JSON data like this:

{
    "status":0,
    "result":"testing"
}

Plugins can filter the output of individual API methods by registering a handler for 'rest:output',$method plugin hook.

Response formats ¶

JSON is the default format, however XML and serialized PHP can be fetched by enabling the data_views plugin and substituting xml or php in place of json in the above URLs.

You can also add additional response formats by defining new viewtypes.

Parameters ¶

Parameters expected by each method should be listed as an associative array, where the key represents the parameter name, and the value contains an array with type, default and required fields.

Values submitted with the API request for each parameter should match the declared type. API will throw on exception if validation fails.

Recognized parameter types are:

integer (or int)

boolean (or bool)

string

float

array

Unrecognized types will throw an API exception.

You can use additional fields to describe your parameter, e.g. description.

elgg_ws_expose_function(
        'test.greet',
        'my_greeting',
        [
                'name' => [
                        'type' => 'string',
                        'required' => true,
                        'description' => 'Name of the person to be greeted by the API',
                ],
                'greeting' => [
                        'type' => 'string',
                        'required' => false,
                        'default' => 'Hello',
                        'description' => 'Greeting to be used, e.g. "Good day" or "Hi"',
                ],
        ],
        'A testing method which greets the user with a custom greeting',
        'GET',
        false,
        false
);

Bemerkung

If a missing parameter has no default value, the argument will be null. Before Elgg v2.1, a bug caused later arguments to be shifted left in this case.

Receive parameters as associative array ¶

If you have a large number of method parameters, you can force the execution script to invoke the callback function with a single argument that contains an associative array of parameter => input pairs (instead of each parameter being a separate argument). To do that, set $assoc to true in elgg_ws_expose_function().

function greet_me($values) {
        $name = elgg_extract('name', $values);
        $greeting = elgg_extract('greeting', $values, 'Hello');
        return "$greeting, $name";
}

elgg_ws_expose_function(
        "test.greet",
        "greet_me",
        [
                "name" => [
                        'type' => 'string',
                ],
                "greeting" => [
                        'type' => 'string',
                        'default' => 'Hello',
                        'required' => false,
                ],
        ],
        'A testing method which echos a greeting',
        'GET',
        false,
        false,
        true // $assoc makes the callback receive an associative array
);

Bemerkung

If a missing parameter has no default value, null will be used.

API authentication ¶

You may want to control access to some of the functions that you expose. Perhaps you are exposing functions in order to integrate Elgg with another open source platform on the same server. In that case, you only want to allow that other application access to these methods. Another possibility is that you want to limit what external developers have access to your API. Or maybe you want to limit how many calls a developer can make against your API in a single day.

In all of these cases, you can use Elgg’s API authentication functions to control access. Elgg provides two built-in methods to perform API authentication: key based and HMAC signature based. You can also add your own authentication methods. The key based approach is very similar to what Google, Flickr, or Twitter. Developers can request a key (a random string) and pass that key with all calls that require API authentication. The keys are stored in the database and if an API call is made without a key or a bad key, the call is denied and an error message is returned.

Key-based authentication ¶

As an example, let’s write a function that returns the number of users that have viewed the site in the last x minutes.

function count_active_users($minutes=10) {
    $seconds = 60 * $minutes;
    $count = count(find_active_users($seconds, 9999));
    return $count;
}

Now, let’s expose it and make the number of minutes an optional parameter:

elgg_ws_expose_function(
        "users.active",
        "count_active_users",
        [
                "minutes" => [
                        'type' => 'int',
                        'required' => false,
                ],
        ],
        'Number of users who have used the site in the past x minutes',
        'GET',
        true,
        false
);

This function is now available and if you check system.api.list, you will see that it requires API authentication. If you hit the method with a web browser, it will return an error message about failing the API authentication. To test this method, you need an API key. As of Elgg 3.2 API keys can be generated by the webservices plugin. It will return a public and private key and you will use the public key for this kind of API authentication. Grab a key and then do a GET request with your browser on this API method passing in the key string as the parameter api_key. It might look something like this: http://yoursite.com/services/api/rest/xml/?method=users.active&api_key=1140321cb56c71710c38feefdf72bc462938f59f.

Signature-based authentication ¶

The HMAC Authentication is similar to what is used with OAuth or Amazon’s S3 service. This involves both the public and private key. If you want to be very sure that the API calls are coming from the developer you think they are coming from and you want to make sure the data is not being tampered with during transmission, you would use this authentication method. Be aware that it is much more involved and could turn off developers when there are other sites out there with key-based authentication.

User authentication ¶

So far you have been allowing developers to pull data out of your Elgg site. Now we’ll move on to pushing data into Elgg. In this case, it is going to be done by a user. Maybe you have created a desktop application that allows your Users to post to the wire without going to the site. You need to expose a method for posting to the wire and you need to make sure that a user cannot post using someone else’s account. Elgg provides a token-based approach for user authentication. It allows a user to submit their username and password in exchange for a token using the method auth.gettoken. This token can then be used for some amount of time to authenticate all calls to the API before it expires by passing it as the parameter auth_token. If you do not want to have your users trusting their passwords to 3rd-party applications, you can also extend the current capability to use an approach like OAuth.

Let’s write our wire posting function:

function my_post_to_wire($text) {

    $text = substr($text, 0, 140);

    $access = ACCESS_PUBLIC;

    // returns guid of wire post
    return thewire_save_post($text, $access, "api");
}

Exposing this function is the same as the previous except we require user authentication and we’re going to make this use POST rather than GET HTTP requests.

elgg_ws_expose_function(
        "thewire.post",
        "my_post_to_wire",
        [
                "text" => [
                        'type' => 'string',
                ],
        ],
        'Post to the wire. 140 characters or less',
        'POST',
        true,
        true
);

Please note that you will not be able to test this using a web browser as you did with the other methods. You need to write some client code to do this.

Building out your API ¶

As soon as you feel comfortable with Elgg’s web services API framework, you will want to step back and design your API. What sort of data are you trying to expose? Who or what will be API users? How do you want them to get access to authentication keys? How are you going to document your API? Be sure to take a look at the APIs created by popular Web 2.0 sites for inspiration. If you are looking for 3rd party developers to build applications using your API, you will probably want to provide one or more language-specific clients.

Determining the authentication available ¶

Elgg’s web services API uses a type of pluggable authentication module (PAM) architecture to manage how users and developers are authenticated. This provides you the flexibility to add and remove authentication modules. Do you want to not use the default user authentication PAM but would prefer using OAuth? You can do this.

The first step is registering a callback function for the rest, init plugin hook:

register_plugin_hook('rest', 'init', 'rest_plugin_setup_pams');

Then in the callback function, you register the PAMs that you want to use:

function rest_plugin_setup_pams() {
    // user token can also be used for user authentication
    register_pam_handler('pam_auth_usertoken');

    // simple API key check
    register_pam_handler('api_auth_key', "sufficient", "api");

    // override the default pams
    return true;
}

When testing, you may find it useful to register the pam_auth_session PAM so that you can easily test your methods from the browser. Be careful not to use this PAM on a production site because it could open up your users to a CSRF attack.

Widgets¶

Widgets are content areas that users can drag around their page to customize the layout. They can typically be customized by their owner to show more/less content and determine who sees the widget. By default Elgg provides plugins for customizing the profile page and dashboard via widgets.

Contents

Structure
Register the widget
Default widgets

Structure ¶

To create a widget, create two views:

widgets/widget/edit
widgets/widget/content

content.php is responsible for all the content that will output within the widget. The edit.php file contains any extra edit functions you wish to present to the user. You do not need to add access level as this comes as part of the widget framework.

Bemerkung

Using HTML checkboxes to set widget flags is problematic because if unchecked, the checkbox input is omitted from form submission. The effect is that you can only set and not clear flags. The „input/checkboxes“ view will not work properly in a widget’s edit panel.

Register the widget ¶

Once you have created your edit and view pages, you need to initialize the plugin widget.

The easiest way to do this is to add the widgets section to your elgg-plugin.php config file.

return [
        'widgets' => [
                'filerepo' => [
                        'context' => ['profile'],
                ],
        ]
];

Alternatively you can also use an function to add a widget. This is done within the plugins init() function.

// Add generic new file widget
elgg_register_widget_type([
    'id' => 'filerepo',
    'name' => elgg_echo('widgets:filerepo:name'),
    'description' => elgg_echo('widgets:filerepo:description'),
    'context' => ['profile'],
]);

Bemerkung

The only required attribute is the id.

Multiple widgets ¶

It is possible to add multiple widgets for a plugin. You just initialize as many widget directories as you need.

// Add generic new file widget
elgg_register_widget_type([
    'id' => 'filerepo',
    'name' => elgg_echo('widgets:filerepo:name'),
    'description' => elgg_echo('widgets:filerepo:description'),
    'context' => ['profile'],
]);

// Add a second file widget
elgg_register_widget_type([
    'id' => 'filerepo2',
    'name' => elgg_echo('widgets:filerepo2:name'),
    'description' => elgg_echo('widgets:filerepo2:description'),
    'context' => ['dashboard'],
]);

// Add a third file widget
elgg_register_widget_type([
    'id' => 'filerepo3',
    'name' => elgg_echo('widgets:filerepo3:name'),
    'description' => elgg_echo('widgets:filerepo3:description'),
    'context' => ['profile', 'dashboard'],
]);

Make sure you have the corresponding directories within your plugin views structure:

'Plugin'
    /views
        /default
            /widgets
               /filerepo
                  /edit.php
                  /content.php
               /filerepo2
                  /edit.php
                  /content.php
               /filerepo3
                  /edit.php
                  /content.php

How to restrict where widgets can be used ¶

The widget can specify the context that it can be used in (just profile, just dashboard, etc.).

elgg_register_widget_type([
    'id' => 'filerepo',
    'context' => ['profile', 'dashboard', 'other_context'],
]);

Allow multiple widgets on the same page ¶

By default you can only add one widget of the same type on the page. If you want more of the same widget on the page, you can specify this when registering the widget:

elgg_register_widget_type([
    'id' => 'filerepo',
    'multiple' => true,
]);

Register widgets in a hook ¶

If, for example, you wish to conditionally register widgets you can also use a hook to register widgets.

function my_plugin_init() {
    elgg_register_plugin_hook_handler('handlers', 'widgets', 'my_plugin_conditional_widgets_hook');
}

function my_plugin_conditional_widgets_hook($hook, $type, $return, $params) {
    if (!elgg_is_active_plugin('file')) {
        return;
    }

    $return[] = \Elgg\WidgetDefinition::factory([
        'id' => 'filerepo',
    ]);

    return $return;
}

Modify widget properties of existing widget registration ¶

If, for example, you wish to change the allowed contexts of an already registered widget you can do so by re-registering the widget with elgg_register_widget_type as it will override an already existing widget definition. If you want even more control you can also use the handlers, widgets hook to change the widget definition.

function my_plugin_init() {
    elgg_register_plugin_hook_handler('handlers', 'widgets', 'my_plugin_change_widget_definition_hook');
}

function my_plugin_change_widget_definition_hook($hook, $type, $return, $params) {
    foreach ($return as $key => $widget) {
        if ($widget->id === 'filerepo') {
            $return[$key]->multiple = false;
        }
    }

    return $return;
}

Default widgets ¶

If your plugin uses the widget canvas, you can register default widget support with Elgg core, which will handle everything else.

To announce default widget support in your plugin, register for the get_list, default_widgets plugin hook:

elgg_register_plugin_hook_handler('get_list', 'default_widgets', 'my_plugin_default_widgets_hook');

In the plugin hook handler, push an array into the return value defining your default widget support and when to create default widgets. Arrays require the following keys to be defined:

name - The name of the widgets page. This is displayed on the tab in the admin interface.
widget_context - The context the widgets page is called from. (If not explicitly set, this is your plugin’s id.)
widget_columns - How many columns the widgets page will use.
event - The Elgg event to create new widgets for. This is usually create.
entity_type - The entity type to create new widgets for.
entity_subtype - The entity subtype to create new widgets for. The can be ELGG_ENTITIES_ANY_VALUE to create for all entity types.

When an object triggers an event that matches the event, entity_type, and entity_subtype parameters passed, Elgg core will look for default widgets that match the widget_context and will copy them to that object’s owner_guid and container_guid. All widget settings will also be copied.

function my_plugin_default_widgets_hook($hook, $type, $return, $params) {
    $return[] = array(
        'name' => elgg_echo('my_plugin'),
        'widget_context' => 'my_plugin',
        'widget_columns' => 3,

        'event' => 'create',
        'entity_type' => 'user',
        'entity_subtype' => ELGG_ENTITIES_ANY_VALUE,
    );

    return $return;
}

Tutorials¶

Walk through all the required steps in order to customize Elgg.

The instructions are detailed enough that you don’t need much previous experience with Elgg.

Hallo Welt¶

This tutorial shows you how to create a new plugin that consists of a new page with the text „Hello world“ on it.

Before anything else, you need to install Elgg.

In this tutorial we will pretend your site’s URL is https://elgg.example.com.

First, create a directory that will contain the plugin’s files. It should be located under the mod/ directory which is located in your Elgg installation directory. So in this case, create mod/hello/.

Manifest file¶

Elgg requires that your plugin has a manifest file that contains information about the plugin. Therefore, in the directory you just created, create a file called manifest.xml and copy this code into it:

<?xml version="1.0" encoding="UTF-8"?>
<plugin_manifest xmlns="http://www.elgg.org/plugin_manifest/1.8">
    <name>Hello world</name>
    <id>hello</id>
    <author>Your Name Here</author>
    <version>0.1</version>
    <description>Hello world, testing.</description>
    <requires>
        <type>elgg_release</type>
        <version>2.0</version>
    </requires>
</plugin_manifest>

This is the minimum amount of information in a manifest file:

<name> is the display name of the plugin
<id> must be the same as the directory you just created
<requires> must include which version of Elgg your plugin requires
<author>, <version> and <description> should have some appropriate values but can be filled freely

Initializer¶

Next, create start.php in the mod/hello/ directory and copy this code into it:

<?php

elgg_register_event_handler('init', 'system', 'hello_world_init');

function hello_world_init() {

}

The above code tells Elgg that it should call the function hello_world_init() once the Elgg core system is initiated.

Registering a route¶

The next step is to register a route which has the purpose of handling request that users make to the URL https://elgg.example.com/hello.

Update elgg-plugin.php to look like this:

<?php

return [
    'routes' => [
                'default:hello' => [
                        'path' => '/hello',
                        'resource' => 'hello',
                ],
        ],
];

This registration tells Elgg that it should call the resource view hello when a user navigates to https://elgg.example.com/hello.

View file¶

Create mod/hello/views/default/resources/hello.php with this content:

<?php

$body = elgg_view_layout('content', [
    'title' => 'Hello world!',
    'content' => 'My first page!',
    'filter' => '',
]);

echo elgg_view_page('Hello', $body);

The code creates an array of parameters to be given to the elgg_view_layout() function, including:

Den Titel der Seite

Den Inhalt der Seite

Einen Filter, der allerdings leer ist, da momentan nichts zu filtern ist

Dadurch wird das grundlegende Layout der Seite definiert. Diese Layout-Definition wird dann von der elgg_view_page()-Funktion verarbeitet, die den Inhalt der Seite zusammenstellt und sie schließlich darstellt.

Last step¶

Finally, activate the plugin through your Elgg administrator page: https://elgg.example.com/admin/plugins (the new plugin appears at the bottom).

You can now go to the address https://elgg.example.com/hello/ and you should see your new page!

Anpassung der Homepage¶

To override the homepage, just override Elgg’s resources/index view by creating a file at /views/default/resources/index.php.

Any output from this view will become your new homepage.

You can take a similar approach with any other page in Elgg or official plugins.

Erstellen eines Blog-Plugins¶

This tutorial will teach you how to create a simple blog plugin. The basic functions of the blog will be creating posts, saving them and viewing them. The plugin duplicates features that are found in the bundled blog plugin. You can disable the bundled blog plugin if you wish, but it is not necessary since the features do not conflict each other.

Arbeitschritte

Create the plugin’s directory and manifest file
Create the form for creating a new blog post
Erstellung einer Seite für das Verfassen der Blogs
Create the action file for saving the blog post
Create elgg-plugin.php
Create start.php
Create a page for viewing a blog post
Create the object view
Testen des Plugins
Displaying a list of blog posts
Fazit

Prerequisites:

Install Elgg

Create the plugin’s directory and manifest file ¶

First, choose a simple and descriptive name for your plugin. In this tutorial, the name will be my_blog. Then, create a directory for your plugin in the /mod/ directory found in your Elgg installation directory. Other plugins are also located in /mod/. In this case, the name of the directory should be /mod/my_blog/. This directory is the root of your plugin and all the files that you create for the new plugin will go somewhere under it.

Next, in the root of the plugin, create the plugin’s manifest file, manifest.xml:

<?xml version="1.0" encoding="UTF-8"?>
<plugin_manifest xmlns="http://www.elgg.org/plugin_manifest/1.8">
    <name>My Blog</name>
    <id>my_blog</id>
    <author>Your Name Here</author>
    <version>0.1</version>
    <description>Adds blogging capabilities.</description>
    <requires>
        <type>elgg_release</type>
        <version>2.0</version>
    </requires>
</plugin_manifest>

See Plugins for more information about the manifest file.

Create the form for creating a new blog post ¶

Create a file at /mod/my_blog/views/default/forms/my_blog/save.php that contains the form body. The form should have input fields for the title, body and tags of the my_blog post. It does not need form tag markup.

echo elgg_view_field([
    '#type' => 'text',
    '#label' => elgg_echo('title'),
    'name' => 'title',
    'required' => true,
]);

echo elgg_view_field([
    '#type' => 'longtext',
    '#label' => elgg_echo('body'),
    'name' => 'body',
    'required' => true,
]);

echo elgg_view_field([
    '#type' => 'tags',
    '#label' => elgg_echo('tags'),
    '#help' => elgg_echo('tags:help'),
    'name' => 'tags',
]);

$submit = elgg_view_field(array(
    '#type' => 'submit',
    '#class' => 'elgg-foot',
    'value' => elgg_echo('save'),
));
elgg_set_form_footer($submit);

Notice how the form is calling elgg_view_field() to render inputs. This helper function maintains consistency in field markup, and is used as a shortcut for rendering field elements, such as label, help text, and input. See Forms + Actions.

You can see a complete list of input views in the /vendor/elgg/elgg/views/default/input/ directory.

It is recommended that you make your plugin translatable by using elgg_echo() whenever there is a string of text that will be shown to the user. Read more at Internationalization.

Erstellung einer Seite für das Verfassen der Blogs ¶

Create the file /mod/my_blog/views/default/resources/my_blog/add.php. This page will view the form you created in the above section.

<?php
// make sure only logged in users can see this page
gatekeeper();

// set the title
$title = "Create a new my_blog post";

// start building the main column of the page
$content = elgg_view_title($title);

// add the form to the main column
$content .= elgg_view_form("my_blog/save");

// optionally, add the content for the sidebar
$sidebar = "";

// layout the page
$body = elgg_view_layout('one_sidebar', array(
   'content' => $content,
   'sidebar' => $sidebar
));

// draw the page, including the HTML wrapper and basic page layout
echo elgg_view_page($title, $body);

The function elgg_view_form("my_blog/save") views the form that you created in the previous section. It also automatically wraps the form with a <form> tag and the necessary attributes as well as anti-csrf tokens.

The form’s action will be "<?= elgg_get_site_url() ?>action/my_blog/save".

Create the action file for saving the blog post ¶

The action file will save the my_blog post to the database. Create the file /mod/my_blog/actions/my_blog/save.php:

<?php
// get the form inputs
$title = get_input('title');
$body = get_input('body');
$tags = string_to_tag_array(get_input('tags'));

// create a new my_blog object and put the content in it
$blog = new ElggObject();
$blog->title = $title;
$blog->description = $body;
$blog->tags = $tags;

// the object can and should have a subtype
$blog->subtype = 'my_blog';

// for now, make all my_blog posts public
$blog->access_id = ACCESS_PUBLIC;

// owner is logged in user
$blog->owner_guid = elgg_get_logged_in_user_guid();

// save to database and get id of the new my_blog
$blog_guid = $blog->save();

// if the my_blog was saved, we want to display the new post
// otherwise, we want to register an error and forward back to the form
if ($blog_guid) {
   system_message("Your blog post was saved.");
   forward($blog->getURL());
} else {
   register_error("The blog post could not be saved.");
   forward(REFERER); // REFERER is a global variable that defines the previous page
}

As you can see in the above code, Elgg objects have several fields built into them. The title of the my_blog post is stored in the title field while the body is stored in the description field. There is also a field for tags which are stored as metadata.

Objects in Elgg are a subclass of something called an „entity“. Users, sites, and groups are also subclasses of entity. An entity’s subtype allows granular control for listing and displaying, which is why every entity should have a subtype. In this tutorial, the subtype „my_blog“ identifies a my_blog post, but any alphanumeric string can be a valid subtype. When picking subtypes, be sure to pick ones that make sense for your plugin.

The getURL method fetches the URL of the new post. It is recommended that you override this method. The overriding will be done in the start.php file.

Create elgg-plugin.php ¶

The /mod/my_blog/elgg-plugin.php file is used to declare various functionalities of the plugin. It can, for example, be used to configure entities, actions, widgets and routes.

<?php

return [
        'entities' => [
                [
                        'type' => 'object',
                        'subtype' => 'my_blog',
                        'searchable' => true,
                ],
        ],
        'actions' => [
                'my_blog/save' => [],
        ],
        'routes' => [
                'view:object:blog' => [
                        'path' => '/my_blog/view/{guid}/{title?}',
                        'resource' => 'my_blog/view',
                ],
                'add:object:blog' => [
                        'path' => '/my_blog/add/{guid?}',
                        'resource' => 'my_blog/add',
                ],
                'edit:object:blog' => [
                        'path' => '/my_blog/edit/{guid}/{revision?}',
                        'resource' => 'my_blog/edit',
                        'requirements' => [
                                'revision' => '\d+',
                        ],
                ],
        ],
];

Create start.php ¶

The /mod/my_blog/start.php file needs to register a hook to override the URL generation.

<?php

function my_blog_init() {
    // register a hook handler to override urls
    elgg_register_plugin_hook_handler('entity:url', 'object', 'my_blog_set_url');
}

return function() {
    // register an initializer
    elgg_register_event_handler('init', 'system', 'my_blog_init');
}

Registering the save action will make it available as /action/my_blog/save. By default, all actions are available only to logged in users. If you want to make an action available to only admins or open it up to unauthenticated users, you can pass ‚admin‘ or ‚public‘ as the third parameter of elgg_register_action.

The URL overriding function will extract the ID of the given entity and use it to make a simple URL for the page that is supposed to view the entity. In this case the entity should of course be a my_blog post. Add this function to your start.php file:

function my_blog_set_url($hook, $type, $url, $params) {
    $entity = $params['entity'];
    if ($entity->getSubtype() === 'my_blog') {
        return "my_blog/view/{$entity->guid}";
    }
}

The page handler makes it possible to serve the page that generates the form and the page that views the post. The next section will show how to create the page that views the post. Add this function to your start.php file:

function my_blog_page_handler($segments) {
    if ($segments[0] == 'add') {
        echo elgg_view_resource('my_blog/add');
        return true;
    }

    else if ($segments[0] == 'view') {
        $resource_vars['guid'] = elgg_extract(1, $segments);
        echo elgg_view_resource('my_blog/view', $resource_vars);
        return true;
    }

    return false;
}

The $segments variable contains the different parts of the URL as separated by /.

Page handling functions need to return true or false. true means the page exists and has been handled by the page handler. false means that the page does not exist and the user will be forwarded to the site’s 404 page (requested page does not exist or not found). In this particular example, the URL must contain either /my_blog/add or /my_blog/view/id where id is a valid ID of an entity with the my_blog subtype. More information about page handling is at Page handler.

Create a page for viewing a blog post ¶

To be able to view a my_blog post on its own page, you need to make a view page. Create the file /mod/my_blog/views/default/resources/my_blog/view.php:

<?php

// get the entity
$guid = elgg_extract('guid', $vars);
$my_blog = get_entity($guid);

// get the content of the post
$content = elgg_view_entity($my_blog, array('full_view' => true));

$params = [
    'title' => $my_blog->getDisplayName(),
    'content' => $content,
    'filter' => '',
];

$body = elgg_view_layout('content', $params);

echo elgg_view_page($my_blog->getDisplayName(), $body);

This page has much in common with the add.php page. The biggest differences are that some information is extracted from the my_blog entity, and instead of viewing a form, the function elgg_view_entity is called. This function gives the information of the entity to something called the object view.

Create the object view ¶

When elgg_view_entity is called or when my_blogs are viewed in a list for example, the object view will generate the appropriate content. Create the file /mod/my_blog/views/default/object/my_blog.php:

<?php

echo elgg_view('output/longtext', array('value' => $vars['entity']->description));
echo elgg_view('output/tags', array('tags' => $vars['entity']->tags));

As you can see in the previous section, each my_blog post is passed to the object view as $vars['entity']. ($vars is an array used in the views system to pass variables to a view.)

Der Code in der letzten Zeile erzeugt aus den Tags eines my_blog-Eintrags eine Reihe von anklickbaren Links und stellt diese dar. Die Möglichkeit einer Suche nach anderen Einträgen mit denselben Tags bei einem Klick auf einen solchen Link ist in Elgg selbst bereits standardmäßig implementiert.

(If you’re wondering about the „default“ in /views/default/, you can create alternative views. RSS, OpenDD, FOAF, mobile and others are all valid view types.)

Testen des Plugins ¶

Go to your Elgg site’s administration page, list the plugins and activate the my_blog plugin.

The page to create a new my_blog post should now be accessible at https://elgg.example.com/my_blog/add, and after successfully saving the post, you should see it viewed on its own page.

Displaying a list of blog posts ¶

Nun wollen wir eine Seite hinzufügen, die die verfügbaren my_blog-Einträge auflistet.

Create /mod/my_blog/views/default/resources/my_blog/all.php:

<?php
$titlebar = "All Site My_Blogs";
$pagetitle = "List of all my_blogs";

$body = elgg_list_entities(array(
    'type' => 'object',
    'subtype' => 'my_blog',
));

$body = elgg_view_title($pagetitle) . elgg_view_layout('one_column', array('content' => $body));

echo elgg_view_page($titlebar, $body);

The elgg_list_entities function grabs the latest my_blog posts and passes them to the object view file. Note that this function returns only the posts that the user can see, so access restrictions are handled transparently. The function (and its cousins) also transparently handles pagination and even creates an RSS feed for your my_blogs if you have defined that view.

The list function can also limit the my_blog posts to those of a specified user. For example, the function elgg_get_logged_in_user_guid grabs the Global Unique IDentifier (GUID) of the logged in user, and by giving that to elgg_list_entities, the list only displays the posts of the current user:

echo elgg_list_entities(array(
    'type' => 'object',
    'subtype' => 'my_blog',
    'owner_guid' => elgg_get_logged_in_user_guid()
));

Next, you will need to modify your my_blog page handler to grab the new page when the URL is set to /my_blog/all. Change the my_blog_page_handler function in start.php to look like this:

function my_blog_page_handler($segments) {
    switch ($segments[0]) {
        case 'add':
           echo elgg_view_resource('my_blog/add');
           break;

        case 'view':
            $resource_vars['guid'] = elgg_extract(1, $segments);
            echo elgg_view_resource('my_blog/view', $resource_vars);
            break;

        case 'all':
        default:
           echo elgg_view_resource('my_blog/all');
           break;
    }

    return true;
}

Now, if the URL contains /my_blog/all, the user will see an „All Site My_Blogs“ page. Because of the default case, the list of all my_blogs will also be shown if the URL is something invalid, like /my_blog or /my_blog/xyz.

You might also want to update the object view to handle different kinds of viewing, because otherwise the list of all my_blogs will also show the full content of all my_blogs. Change /mod/my_blog/views/default/object/my_blog.php to look like this:

<?php
$full = elgg_extract('full_view', $vars, FALSE);

// full view
if ($full) {
    echo elgg_view('output/longtext', array('value' => $vars['entity']->description));
    echo elgg_view('output/tags', array('tags' => $vars['entity']->tags));

// list view or short view
} else {
    // make a link out of the post's title
    echo elgg_view_title(
        elgg_view('output/url', array(
            'href' => $vars['entity']->getURL(),
            'text' => $vars['entity']->getDisplayName(),
            'is_trusted' => true,
    )));
    echo elgg_view('output/tags', array('tags' => $vars['entity']->tags));
}

Now, if full_view is true (as it was pre-emptively set to be in this section), the object view will show the post’s content and tags (the title is shown by view.php). Otherwise the object view will render just the title and tags of the post.

Fazit ¶

There’s much more that could be done, but hopefully this gives you a good idea of how to get started.

Einbinden eines Rich Text-Editors¶

Erstelle Dein eigenes WYSIWYG-Editor-Plugin.

Elgg enthält standardmäßig ein Plugin, das CKEditor- als Rich Text-Editor verwendet (frühere Versionen verwendeten den TinyMCE-Editor). Wenn Du allerdings einen anderen WYSIWYG-Editor bevorzugst, kannst Du anhand dieser Anleitung ein Plugin entwickeln, das den Editor Deiner Wahl verwendet.

All forms in Elgg should try to use the provided input views located in views/default/input. If these views are used, then it is simple for plugin authors to replace a view, in this case input/longtext, with their wysiwyg.

Hinzufügen der Laufzeit-Bibliotheken des Editors¶

Now you need to upload TinyMCE into a directory in your plugin. We strongly encourage you to use composer to manage third-party dependencies, since it is so much easier to upgrade and maintain that way:

.. code-block:: sh

composer require bower-asset/tinymce

Elgg mitteilen, wann und wie TinyMCE zu laden ist¶

Du hast nun:

Deine start-Datei erzeugt

das Plugin initialisiert

den Code des WYSIWYG-Editors hinzugefügt

Es ist nun Zeit, Elgg mitzuteilen, wie TinyMCE bei longtext-Eingabefeldern zu verwenden ist.

Dazu erweitern wir die input/longtext-View und fügen ein wenig Javascript-Code hinzu. Erzeuge eine View namens tinymce/longtext und füge folgenden Code in ihr hinzu:

<?php

    /**
     * Elgg long text input with the tinymce text editor intacts
     * Displays a long text input field
     *
     * @package ElggTinyMCE
     *
     *
     */

?>
<!-- include tinymce -->
<script language="javascript" type="text/javascript" src="<?php echo $vars['url']; ?>mod/tinymce/tinymce/jscripts/tiny_mce/tiny_mce.js"></script>
<!-- intialise tinymce, you can find other configurations here http://wiki.moxiecode.com/examples/tinymce/installation_example_01.php -->
<script language="javascript" type="text/javascript">
   tinyMCE.init({
    mode : "textareas",
    theme : "advanced",
    theme_advanced_buttons1 : "bold,italic,underline,separator,strikethrough,justifyleft,justifycenter,justifyright, justifyfull,bullist,numlist,undo,redo,link,unlink,image,blockquote,code",
    theme_advanced_buttons2 : "",
    theme_advanced_buttons3 : "",
    theme_advanced_toolbar_location : "top",
    theme_advanced_toolbar_align : "left",
    theme_advanced_statusbar_location : "bottom",
    theme_advanced_resizing : true,
    extended_valid_elements : "a[name|href|target|title|onclick],img[class|src|border=0|alt|title|hspace|vspace|width|height|align|onmouseover|onmouseout|name],
hr[class|width|size|noshade],font[face|size|color|style],span[class|align|style]"
});
</script>

Erweitere anschließend die input/longtext-View in der Init-Funktion Deines Plugins:

function tinymce_init() {
    elgg_extend_view('input/longtext', 'tinymce/longtext');
}

Das ist alles! Von nun an wird in allen Fällen, in denen ein input/longtext-Eingabefeld verwendet wird, TinyMCE geladen und an Stelle des Texteingabefeldes angezeigt.

Ausgabe eines Widgets¶

In dieser Anleitung wird erläutert, wie ein einfaches Widget erzeugt werden kann, in dem der Text “Hello, World!” und optional noch weiterer von einem Benutzer eingegebener Text angezeigt wird.

Mit Widgets werden in Elgg die Komponenten der Oberfläche bezeichnet, die Du zu Deinem Profil oder dem Admin-Dashboard hinzufügen kannst.

Diese Anleitung setzt voraus, dass Du mit einigen grundlegenden Konzepten von Elgg bereits vertraut bist, wie beispielsweise:

Views

Plugins

Du solltest Dir diese Abschnitte der Elgg-Dokumentation nochmals durchlesen, falls Du beim Durcharbeiten der folgenden Schritte dieser Anleitung Verständnisschwierigkeiten hast.

Arbeitschritte

Hinzufügen der Widget-View
Registrieren des Widgets
Benutzer-spezifische Anpassungen erlauben

Hinzufügen der Widget-View ¶

Elgg automatically scans particular directories under plugins looking for particular files. Views make it easy to add your display code or do other things like override default Elgg behavior. For now, we will just be adding the view code for your widget. Create a file at /views/default/widgets/helloworld/content.php. “helloworld” will be the name of your widget within the hello plugin. In this file add the code:

<?php

echo "Hello, world!";

Im Widget werden dann diese Worte ausgegeben werden. Das Laden des Widgets selbst wird dabei automatisch von Elgg übernommen.

Registrieren des Widgets ¶

Elgg needs to be told explicitly that the plugin contains a widget so that it will scan the widget views directory. This is done by calling the elgg_register_widget_type() function. Edit /start.php. In it add these lines:

<?php

function hello_init() {
    elgg_register_widget_type([
        'id' => 'helloworld',
        'name' => 'Hello, world!',
        'description' => 'The "Hello, world!" widget',
    ]);
}

return function() {
    elgg_register_event_handler('init', 'system', 'hello_init');
}

Gehe jetzt zu Deiner Profilseite innerhalb Deiner Elgg-Seite und füge das “hello, world”-Widget hinzu. Im Widget sollte nun “Hello, world!” angezeigt werden.

Bemerkung

Bei einem produktiv eingesetzten Widget ist es immer empfehlenswert, Internationalization-Unterstützung zu implementieren.

Benutzer-spezifische Anpassungen erlauben ¶

Klicke auf den Bearbeiten-Link in der Titelzeile Deines Widgets. Wie Du siehst, ist die einzige standardmäßig angebotene Option die Anpassung des Zugangslevels (wer das Widget angezeigt bekommt).

Suppose you want to allow the user to control what greeting is displayed in the widget. Just as Elgg automatically loads content.php when viewing a widget, it loads edit.php when a user attempts to edit a widget. Put the following code into /views/default/widgets/helloworld/edit.php:

<div>
    <label>Message:</label>
    <?php
        //This is an instance of the ElggWidget class that represents our widget.
        $widget = $vars['entity'];

        // Give the user a plain text box to input a message
        echo elgg_view('input/text', array(
            'name' => 'params[message]',
            'value' => $widget->message,
            'class' => 'hello-input-text',
        ));
    ?>
</div>

Beachte den Zusammenhang zwischen den Werten, die den ‚name‘- und ‚value‘-Feldern von input/text übergeben werden. Der Name des Texteingabefeldes ist params[message], weil Elgg automatisch Widget-Variablen verarbeitet, die der Feldvariablen params übergeben werden. Der eigentliche Name der PHP-Variablen ist allerdings message. Wenn wir dem Feld stattdessen den Namen greeting anstatt message geben wollten, würden wir die Werte params[greeting] und $widget->greeting übergeben.

Das ‚value‘-Attribut in der Feldvariable setzen wir, damit die Edit-View anzeigen kann, was der Benutzer beim letzten Mal eingegeben hatte als der Text editiert wurde.

Now to display the user’s message we need to modify content.php to use this message variable. Edit /views/default/widgets/helloworld/content.php and change it to:

<?php

$widget = $vars['entity'];

// Always use the corresponding output/* view for security!
echo elgg_view('output/text', array('value' => $widget->message));

Es sollte nun möglich sein, eine Nachricht in die Textbox einzugeben, die dann im Widget angezeigt wird.

Design Docs¶

Gain a deep understanding of how Elgg works and why it’s built the way it is.

Actions¶

Actions are the primary way users interact with an Elgg site.

Overview¶

An action in Elgg is the code that runs to make changes to the database when a user does something. For example, logging in, posting a comment, and making a blog post are actions. The action script processes input, makes the appropriate modifications to the database, and provides feedback to the user about the action.

Action Handler¶

Actions are registered during the boot process by calling elgg_register_action(). All actions URLs start with action/ and are served by Elgg’s front end controller through the action service. This approach is different from traditional PHP applications that send information to a specific file. The action service performs CSRF security checks, and calls the registered action script file, then optionally forwards the user to a new page. By using the action service instead of a single script file, Elgg automatically provides increased security and extensibility.

See Forms + Actions for details on how to register and construct an action. To look at the core actions, check out the directory /actions.

Database¶

A thorough discussion of Elgg’s data model design and motivation.

Contents

Overview ¶

In Elgg, everything runs on a unified data model based on atomic units of data called entities.

Plugins are discouraged from interacting directly with the database, which creates a more stable system and a better user experience because content created by different plugins can be mixed together in consistent ways. With this approach, plugins are faster to develop, and are at the same time much more powerful.

Every entity in the system inherits the ElggEntity class. This class controls access permissions, ownership, containment and provides consistent API for accessing and updating entity properties.

You can extend entities with extra information in two ways:

Metadata: This information describes the entity, it is usually: added by the author of the entity when the entity is created or updated. Examples of metadata include tags, ISBN number or a third-party ID, location, geocoordinates etc. Think of metadata as a simple key-value storage.
Annotations: This information extends the entity with properties usually: added by a third party. Such properties include ratings, likes, and votes.

The main differences between metadata and annotations:

metadata does not have owners, while annotations do
metadata is not access controlled, while annotations are
metadata is preloaded when entity is constructed, while annotations are only loaded on demand

These differences might have implications for performance and your business logic, so consider carefully, how you would like to attach data to your entities.

In certain cases, it may be benefitial to avoid using metadata and annotations and create new entities instead and attaching them via container_guid or a relationship.

Datamodel ¶

The Elgg data model diagram

Entities ¶

ElggEntity is the base class for the Elgg data model and supports a common set of properties and methods.

A numeric Globally Unique IDentifier (See GUIDs).
Access permissions. (When a plugin requests data, it never gets to touch data that the current user doesn’t have permission to see.)
An arbitrary subtype (more below).
An owner.
The site that the entity belongs to.
A container, used to associate content with a group or a user.

Types ¶

Actual entities will be instances of four different subclasses, each having a distinct type property and their own additional properties and methods.

Type	PHP class	Represents
object	`ElggObject`	Most user-created content, like blog posts, uploads, and bookmarks.
group	`ElggGroup`	An organized group of users with its own profile page
user	`ElggUser`	A user of the system
site	`ElggSite`	The site served by the Elgg installation

Each type has its own extended API. E.g. users can be friends with other users, group can have members, while objects can be liked and commented on.

Subtypes ¶

Each entity must define a subtype, which plugins use to further specialize the entity. Elgg makes it easy to query specific for entities of a given subtype(s), as well as assign them special behaviors and views.

Subtypes are most commonly given to instances of ElggEntity to denote the kind of content created. E.g. the blog plugin creates objects with subtype "blog".

By default, users, groups and sites have the the subtypes of user, group and site respectively.

Plugins can use custom entity classes that extend the base type class. To do so, they need to register their class at runtime (e.g. in the 'init','system' handler), using elgg_set_entity_class(). For example, the blog plugin could use elgg_set_entity_class('object', 'blog', \ElggBlog::class).

Plugins can use elgg-plugin.php to define entity class via shortcut entities parameter.

Subtype Gotchas ¶

Before an entity’s save() method is called, the subtype must be set by writing a string to the subtype property.
Subtype cannot be changed after saving.

GUIDs ¶

A GUID is an integer that uniquely identifies every entity in an Elgg installation (a Globally Unique IDentifier). It’s assigned automatically when the entity is first saved and can never be changed.

Some Elgg API functions work with GUIDs instead of ElggEntity objects.

ElggObject ¶

The ElggObject entity type represents arbitrary content within an Elgg install; things like blog posts, uploaded files, etc.

Beyond the standard ElggEntity properties, ElggObjects also support:

title The title of the object (HTML escaped text)
description A description of the object (HTML)

Most other data about the object is generally stored via metadata.

ElggUser ¶

The ElggUser entity type represents users within an Elgg install. These will be set to disabled until their accounts have been activated (unless they were created from within the admin panel).

Beyond the standard ElggEntity properties, ElggUsers also support:

name The user’s plain text name. e.g. „Hugh Jackman“
username Their login name. E.g. „hjackman“
password A hashed version of their password
email Their email address
language Their default language code.
code Their session code (moved to a separate table in 1.9).
last_action The UNIX timestamp of the last time they loaded a page
prev_last_action The previous value of last_action
last_login The UNIX timestamp of their last log in
prev_last_login the previous value of last_login

ElggSite ¶

The ElggSite entity type represents your Elgg installation (via your site URL).

Beyond the standard ElggEntity properties, ElggSites also support:

name The site name
description A description of the site
url The address of the site

ElggGroup ¶

The ElggGroup entity type represents an association of Elgg users. Users can join, leave, and post content to groups.

Beyond the standard ElggEntity properties, ElggGroups also support:

name The group’s name (HTML escaped text)
description A description of the group (HTML)

ElggGroup has addition methods to manage content and membership.

The Groups plugin ¶

Not to be confused with the entity type ElggGroup, Elgg comes with a plugin called „Groups“ that provides a default UI/UX for site users to interact with groups. Each group is given a discussion forum and a profile page linking users to content within the group.

You can alter the user experience via the traditional means of extending plugins or completely replace the Groups plugin with your own.

Writing a group-aware plugin ¶

Plugin owners need not worry too much about writing group-aware functionality, but there are a few key points:

Adding content¶

By passing along the group as container_guid via a hidden input field, you can use a single form and action to add both user and group content.

Use ElggEntity->canWriteToContainer() to determine whether or not the current user has the right to add content to a group.

Be aware that you will then need to pass the container GUID or username to the page responsible for posting and the accompanying value, so that this can then be stored in your form as a hidden input field, for easy passing to your actions. Within a „create“ action, you’ll need to take in this input field and save it as a property of your new element (defaulting to the current user’s container):

$user = elgg_get_logged_in_user_entity();
$container_guid = (int)get_input('container_guid');

if ($container_guid) {
    $container = get_entity($container_guid);

    if (!$container->canWriteToContainer($user->guid)) {
        // register error and forward
    }
} else {
    $container_guid = elgg_get_logged_in_user_guid();
}

$object = new ElggObject;
$object->container_guid = $container_guid;

...

$container = get_entity($container_guid);
forward($container->getURL());

Ownership ¶

Entities have a owner_guid GUID property, which defines its owner. Typically this refers to the GUID of a user, although sites and users themselves often have no owner (a value of 0).

The ownership of an entity dictates, in part, whether or not you can access or edit that entity.

Containers ¶

In order to easily search content by group or by user, content is generally set to be „contained“ by either the user who posted it, or the group to which the user posted. This means the new object’s container_guid property will be set to the GUID of the current ElggUser or the target ElggGroup.

E.g., three blog posts may be owned by different authors, but all be contained by the group they were posted to.

Note: This is not always true. Comment entities are contained by the object commented upon, and in some 3rd party plugins the container may be used to model a parent-child relationship between entities (e.g. a „folder“ object containing a file object).

Annotations ¶

Annotations are pieces of data attached to an entity that allow users to leave ratings, or other relevant feedback. A poll plugin might register votes as annotations.

Annotations are stored as instances of the ElggAnnotation class.

Each annotation has:

An internal annotation type (like comment)
A value (which can be a string or integer)
An access permission distinct from the entity it’s attached to
An owner

Like metadata, values are stored as strings unless the value given is a PHP integer (is_int($value) is true), or unless the $vartype is manually specified as integer.

Adding an annotation ¶

The easiest way to annotate is to use the annotate method on an entity, which is defined as:

public function annotate(
    $name,           // The name of the annotation type (eg 'comment')
    $value,          // The value of the annotation
    $access_id = 0,  // The access level of the annotation
    $owner_id = 0,   // The annotation owner, defaults to current user
    $vartype = ""    // 'text' or 'integer'
)

For example, to leave a rating on an entity, you might call:

$entity->annotate('rating', $rating_value, $entity->access_id);

Reading annotations ¶

To retrieve annotations on an object, you can call the following method:

$annotations = $entity->getAnnotations(
    $name,    // The type of annotation
    $limit,   // The number to return
    $offset,  // Any indexing offset
    $order,   // 'asc' or 'desc' (default 'asc')
);

If your annotation type largely deals with integer values, a couple of useful mathematical functions are provided:

$averagevalue = $entity->getAnnotationsAvg($name);  // Get the average value
$total = $entity->getAnnotationsSum($name);         // Get the total value
$minvalue = $entity->getAnnotationsMin($name);      // Get the minimum value
$maxvalue = $entity->getAnnotationsMax($name);      // Get the maximum value

Useful helper functions ¶

Comments¶

If you want to provide comment functionality on your plugin objects, the following function will provide the full listing, form and actions:

function elgg_view_comments(ElggEntity $entity)

Metadata ¶

Metadata in Elgg allows you to store extra data on an entity beyond the built-in fields that entity supports. For example, ElggObjects only support the basic entity fields plus title and description, but you might want to include tags or an ISBN number. Similarly, you might want users to be able to save a date of birth.

Under the hood, metadata is stored as an instance of the ElggMetadata class, but you don’t need to worry about that in practice (although if you’re interested, see the ElggMetadata class reference). What you need to know is:

Metadata has an owner, which may be different to the owner of the entity it’s attached to
You can potentially have multiple items of each type of metadata attached to a single entity
Like annotations, values are stored as strings unless the value given is a PHP integer (is_int($value) is true), or unless the $value_type is manually specified as integer (see below).

Bemerkung

As of Elgg 3.0, metadata no longer have access_id.

The simple case ¶

Adding metadata¶

To add a piece of metadata to an entity, just call:

$entity->metadata_name = $metadata_value;

For example, to add a date of birth to a user:

$user->dob = $dob_timestamp;

Or to add a couple of tags to an object:

$object->tags = array('tag one', 'tag two', 'tag three');

When adding metadata like this:

The owner is set to the currently logged-in user
Reassigning a piece of metadata will overwrite the old value

This is suitable for most purposes. Be careful to note which attributes are metadata and which are built in to the entity type that you are working with. You do not need to save an entity after adding or updating metadata. You do need to save an entity if you have changed one of its built in attributes. As an example, if you changed the access id of an ElggObject, you need to save it or the change isn’t pushed to the database.

Bemerkung

As of Elgg 3.0, metadata’s access_id property is ignored.

Reading metadata¶

To retrieve metadata, treat it as a property of the entity:

$tags_value = $object->tags;

Note that this will return the absolute value of the metadata. To get metadata as an ElggMetadata object, you will need to use the methods described in the finer control section below.

If you stored multiple values in this piece of metadata (as in the „tags“ example above), you will get an array of all those values back. If you stored only one value, you will get a string or integer back. Storing an array with only one value will return a string back to you. E.g.

$object->tags = array('tag');
$tags = $object->tags;
// $tags will be the string "tag", NOT array('tag')

To always get an array back, simply cast to an array;

$tags = (array)$object->tags;

Reading metadata as objects ¶

elgg_get_metadata is the best function for retrieving metadata as ElggMetadata objects:

E.g., to retrieve a user’s DOB

elgg_get_metadata(array(
    'metadata_name' => 'dob',
    'metadata_owner_guid' => $user_guid,
));

Or to get all metadata objects:

elgg_get_metadata(array(
    'metadata_owner_guid' => $user_guid,
    'limit' => 0,
));

Common mistakes ¶

„Appending“ metadata¶

Note that you cannot „append“ values to metadata arrays as if they were normal php arrays. For example, the following will not do what it looks like it should do.

$object->tags[] = "tag four";

Trying to store hashmaps¶

Elgg does not support storing ordered maps (name/value pairs) in metadata. For example, the following does not work as you might first expect it to:

// Won't work!! Only the array values are stored
$object->tags = array('one' => 'a', 'two' => 'b', 'three' => 'c');

You can instead store the information like so:

$object->one = 'a';
$object->two = 'b';
$object->three = 'c';

Storing GUIDs in metadata¶

Though there are some cases to store entity GUIDs in metadata, Relationships are a much better construct for relating entities to each other.

Relationships ¶

Relationships allow you to bind entities together. Examples: an artist has fans, a user is a member of an organization, etc.

The class ElggRelationship models a directed relationship between two entities, making the statement:

„{subject} is a {noun} of {target}.“

API name	Models	Represents
`guid_one`	The subject	Which entity is being bound
`relationship`	The noun	The type of relationship
`guid_two`	The target	The entity to which the subject is bound

The type of relationship may alternately be a verb, making the statement:

„{subject} {verb} {target}.“

E.g. User A „likes“ blog post B

Each relationship has direction. Imagine an archer shoots an arrow at a target; The arrow moves in one direction, binding the subject (the archer) to the target.

A relationship does not imply reciprocity. A follows B does not imply that B follows A.

Relationships_ do not have access control. They’re never hidden from view and can be edited with code at any privilege level, with the caveat that the entities in a relationship may be invisible due to access control!

Working with relationships ¶

Creating a relationship¶

E.g. to establish that „$user is a fan of $artist“ (user is the subject, artist is the target):

// option 1
$success = add_entity_relationship($user->guid, 'fan', $artist->guid);

// option 2
$success = $user->addRelationship($artist->guid, 'fan');

This triggers the event [create, relationship], passing in the created ElggRelationship object. If a handler returns false, the relationship will not be created and $success will be false.

Verifying a relationship¶

E.g. to verify that „$user is a fan of $artist“:

if (check_entity_relationship($user->guid, 'fan', $artist->guid)) {
    // relationship exists
}

Note that, if the relationship exists, check_entity_relationship() returns an ElggRelationship object:

$relationship = check_entity_relationship($user->guid, 'fan', $artist->guid);
if ($relationship) {
    // use $relationship->id or $relationship->time_created
}

Deleting a relationship¶

E.g. to be able to assert that „$user is no longer a fan of $artist“:

$was_removed = remove_entity_relationship($user->guid, 'fan', $artist->guid);

This triggers the event [delete, relationship], passing in the associated ElggRelationship object. If a handler returns false, the relationship will remain, and $was_removed will be false.

Other useful functions:

delete_relationship() : delete by ID
remove_entity_relationships() : delete those relating to an entity

Access Control ¶

Granular access controls are one of the fundamental design principles in Elgg, and a feature that has been at the centre of the system throughout its development. The idea is simple: a user should have full control over who sees an item of data he or she creates.

Access controls in the data model ¶

In order to achieve this, every entity and annotation contains an access_id property, which in turn corresponds to one of the pre-defined access controls or an entry in the access_collections database table.

Pre-defined access controls¶

ACCESS_PRIVATE (value: 0) Private.
ACCESS_LOGGED_IN (value: 1) Logged in users.
ACCESS_PUBLIC (value: 2) Public data.

User defined access controls¶

You may define additional access groups and assign them to an entity, or annotation. A number of functions have been defined to assist you; see the Access Control Lists for more information.

How access affects data retrieval ¶

All data retrieval functions above the database layer - for example elgg_get_entities will only return items that the current user has access to see. It is not possible to retrieve items that the current user does not have access to. This makes it very hard to create a security hole for retrieval.

Write access ¶

The following rules govern write access:

The owner of an entity can always edit it
The owner of a container can edit anything therein (note that this does not mean that the owner of a group can edit anything therein)
Admins can edit anything

You can override this behaviour using a plugin hook called permissions_check, which passes the entity in question to any function that has announced it wants to be referenced. Returning true will allow write access; returning false will deny it. See the plugin hook reference for permissions_check for more details.

Schema ¶

The database contains a number of primary and secondary tables. You can follow schema changes in engine/schema/migrations/

The character set of the database should be utf8mb4, this will provide full unicode character support when storing data.

InnoDB ¶

As of Elgg 3.0 the database uses the InnoDB engine. In order for a correct installation or migration some settings may need to be adjusted in the database settings.

innodb_large_prefix should be on
innodb_file_format should be Barracuda
innodb_file_per_table should be 1

Main tables ¶

This is a description of the main tables. Keep in mind that in a given Elgg installation, the tables will have a prefix (typically „elgg_“).

Table: entities¶

This is the main Entities table containing Elgg users, sites, objects and groups. When you first install Elgg this is automatically populated with your first site.

It contains the following fields:

guid An auto-incrementing counter producing a GUID that uniquely identifies this entity in the system
type The type of entity - object, user, group or site
subtype A subtype of entity
owner_guid The GUID of the owner’s entity
container_guid The GUID this entity is contained by - either a user or a group
access_id Access controls on this entity
time_created Unix timestamp of when the entity is created
time_updated Unix timestamp of when the entity was updated
enabled If this is ‚yes‘ an entity is accessible, if ‚no‘ the entity has been disabled (Elgg treats it as if it were deleted without actually removing it from the database)

Table: metadata¶

This table contains Metadata, extra information attached to an entity.

id A unique IDentifier
entity_guid The entity this is attached to
name The name string
value The value string
value_type The value class, either text or an integer
time_created Unix timestamp of when the metadata is created
enabled If this is ‚yes‘ an item is accessible, if ‚no‘ the item has been disabled

Table: annotations¶

This table contains Annotations, this is distinct from Metadata.

id A unique IDentifier
entity_guid The entity this is attached to
name The name string
value The value string
value_type The value class, either text or an integer
owner_guid The owner GUID of the owner who set this annotation
access_id An Access controls on this annotation
time_created Unix timestamp of when the annotation is created.
enabled If this is ‚yes‘ an item is accessible, if ‚no‘ the item has been disabled

Table: relationships¶

This table defines Relationships, these link one entity with another.

guid_one The GUID of the subject entity.
relationship The type of the relationship.
guid_two The GUID of the target entity.

Secundairy tables ¶

Table: access_collections¶

This table defines Access Collections, which grant users access to Entities or Annotations.

id A unique IDentifier
*name The name of the access collection
owner_guid The GUID of the owning entity (eg. a user or a group)
subtype the subtype of the access collection (eg. friends or group_acl)

Events and Plugin Hooks¶

Contents

Overview
- Elgg Events vs. Plugin Hooks
Elgg Events
Plugin Hooks

Overview ¶

Elgg has an event system that can be used to replace or extend core functionality.

Plugins influence the system by creating handlers (callables such as functions and methods) and registering them to handle two types of events: Elgg Events and Plugin Hooks.

When an event is triggered, a set of handlers is executed in order of priority. Each handler is passed arguments and has a chance to influence the process. After execution, the „trigger“ function returns a value based on the behavior of the handlers.

Siehe auch

Elgg Events vs. Plugin Hooks ¶

The main differences between Elgg Events and Plugin Hooks are:

Most Elgg events can be cancelled; unless the event is an „after“ event, a handler that returns false can cancel the event, and no more handlers are called.
Plugin hooks cannot be cancelled; all handlers are always called.
Plugin hooks pass an arbitrary value through the handlers, giving each a chance to alter along the way.

Elgg Events ¶

Elgg Events are triggered when an Elgg object is created, updated, or deleted; and at important milestones while the Elgg framework is loading. Examples: a blog post being created or a user logging in.

Unlike Plugin Hooks, most Elgg events can be cancelled, halting the execution of the handlers, and possibly cancelling an some action in the Elgg core.

Each Elgg event has a name and an object type (system, user, object, relationship name, annotation, group) describing the type of object passed to the handlers.

Before and After Events ¶

Some events are split into „before“ and „after“. This avoids confusion around the state of the system while in flux. E.g. Is the user logged in during the [login, user] event?

Before Events have names ending in „:before“ and are triggered before something happens. Like traditional events, handlers can cancel the event by returning false.

After Events, with names ending in „:after“, are triggered after something happens. Unlike traditional events, handlers cannot cancel these events; all handlers will always be called.

Where before and after events are available, developers are encouraged to transition to them, though older events will be supported for backwards compatibility.

Elgg Event Handlers ¶

Elgg event handlers are callables with one of the following prototypes:

<?php

/**
 * @param \Elgg\Event $event The event object
 *
 * @return bool if false, the handler is requesting to cancel the event
 */
function event_handler1(\Elgg\Event $event) {
    ...
}

/**
 * @param string $event       The name of the event
 * @param string $object_type The type of $object (e.g. "user", "group")
 * @param mixed  $object      The object of the event
 *
 * @return bool if false, the handler is requesting to cancel the event
 */
function event_handler2($event, $object_type, $object) {
    ...
}

In event_handler1, the Event object has various methods for getting the name, object type, and object of the event. See the Elgg\Event interface for details.

In both cases, if a handler returns false, the event is cancelled, preventing execution of the other handlers. All other return values are ignored.

Bemerkung

If the event type is „object“ or „user“, use type hint \Elgg\ObjectEvent or \Elgg\UserEvent instead, which clarify the return type of the getObject() method.

Register to handle an Elgg Event ¶

Register your handler to an event using elgg_register_event_handler:

<?php

elgg_register_event_handler($event, $object_type, $handler, $priority);

Parameters:

$event The event name.
$object_type The object type (e.g. „user“ or „object“) or ‚all‘ for all types on which the event is fired.
$handler The callback of the handler function.
$priority The priority - 0 is first and the default is 500.

Object here does not refer to an ElggObject but rather a string describing any object in the framework: system, user, object, relationship, annotation, group.

Example:

<?php

// Register the function myPlugin_handle_create_object() to handle the
// create object event with priority 400.
elgg_register_event_handler('create', 'object', 'myPlugin_handle_create_object', 400);

Warnung

If you handle the „update“ event on an object, avoid calling save() in your event handler. For one it’s probably not necessary as the object is saved after the event completes, but also because save() calls another „update“ event and makes $object->getOriginalAttributes() no longer available.

Invokable classes as handlers¶

You may use a class with an __invoke() method as a handler. Just register the class name and it will be instantiated (with no arguments) for the lifetime of the event (or hook).

<?php

namespace MyPlugin;

class UpdateObjectHandler {
    public function __invoke(\Elgg\ObjectEvent $event) {

    }
}

// in init, system
elgg_register_event_handler('update', 'object', MyPlugin\UpdateObjectHandler::class);

Trigger an Elgg Event ¶

You can trigger a custom Elgg event using elgg_trigger_event:

<?php

if (elgg_trigger_event($event, $object_type, $object)) {
    // Proceed with doing something.
} else {
    // Event was cancelled. Roll back any progress made before the event.
}

For events with ambiguous states, like logging in a user, you should use Before and After Events by calling elgg_trigger_before_event or elgg_trigger_after_event. This makes it clear for the event handler what state to expect and which events can be cancelled.

<?php

// handlers for the user, login:before event know the user isn't logged in yet.
if (!elgg_trigger_before_event('login', 'user', $user)) {
    return false;
}

// handlers for the user, login:after event know the user is logged in.
elgg_trigger_after_event('login', 'user', $user);

Parameters:

$event The event name.
$object_type The object type (e.g. „user“ or „object“).
$object The object (e.g. an instance of ElggUser or ElggGroup)

The function will return false if any of the selected handlers returned false and the event is stoppable, otherwise it will return true.

Plugin Hooks ¶

Plugin Hooks provide a way for plugins to collaboratively determine or alter a value. For example, to decide whether a user has permission to edit an entity or to add additional configuration options to a plugin.

A plugin hook has a value passed into the trigger function, and each handler has an opportunity to alter the value before it’s passed to the next handler. After the last handler has completed, the final value is returned by the trigger.

Plugin Hook Handlers ¶

Hook handlers are callables with one of the following prototypes:

<?php

/**
 * @param \Elgg\Hook $hook The hook object
 *
 * @return mixed if not null, this will be the new value of the plugin hook
 */
function plugin_hook_handler1(\Elgg\Hook $hook) {
    ...
}

/**
 * @param string $hook    The name of the plugin hook
 * @param string $type    The type of the plugin hook
 * @param mixed  $value   The current value of the plugin hook
 * @param mixed  $params  Data passed from the trigger
 *
 * @return mixed if not null, this will be the new value of the plugin hook
 */
function plugin_hook_handler2($hook, $type, $value, $params) {
    ...
}

In plugin_hook_handler1, the Hook object has various methods for getting the name, type, value, and parameters of the hook. See the Elgg\Hook interface for details.

In both cases, if the handler returns no value (or null explicitly), the plugin hook value is not altered. Otherwise the returned value becomes the new value of the plugin hook, and it will then be available as $hook->getValue() (or $value) in the next handler.

Register to handle a Plugin Hook ¶

Register your handler to a plugin hook using elgg_register_plugin_hook_handler:

<?php

elgg_register_plugin_hook_handler($hook, $type, $handler, $priority);

Parameters:

$hook The name of the plugin hook.
$type The type of the hook or ‚all‘ for all types.
$handler The callback of the handler function.
$priority The priority - 0 is first and the default is 500.

Type can vary in meaning. It may mean an Elgg entity type or something specific to the plugin hook name.

Example:

<?php

// Register the function myPlugin_hourly_job() to be called with priority 400.
elgg_register_plugin_hook_handler('cron', 'hourly', 'myPlugin_hourly_job', 400);

Trigger a Plugin Hook ¶

You can trigger a custom plugin hook using elgg_trigger_plugin_hook:

<?php

// filter $value through the handlers
$value = elgg_trigger_plugin_hook($hook, $type, $params, $value);

Parameters:

$hook The name of the plugin hook.
$type The type of the hook or ‚all‘ for all types.
$params Arbitrary data passed from the trigger to the handlers.
$value The initial value of the plugin hook.

Warnung

The $params and $value arguments are reversed between the plugin hook handlers and trigger functions!

Unregister Event/Hook Handlers ¶

The functions elgg_unregister_event_handler and elgg_unregister_plugin_hook_handler can be used to remove handlers already registered by another plugin or Elgg core. The parameters are in the same order as the registration functions, except there’s no priority parameter.

<?php

elgg_unregister_event_handler('login', 'user', 'myPlugin_handle_login');

Anonymous functions or invokable objects cannot be unregistered, but dynamic method callbacks can be unregistered by giving the static version of the callback:

<?php

$obj = new MyPlugin\Handlers();
elgg_register_plugin_hook_handler('foo', 'bar', [$obj, 'handleFoo']);

// ... elsewhere

elgg_unregister_plugin_hook_handler('foo', 'bar', 'MyPlugin\Handlers::handleFoo');

Even though the event handler references a dynamic method call, the code above will successfully remove the handler.

Handler Calling Order ¶

Handlers are called first in order of priority, then registration order.

Bemerkung

Before Elgg 2.0, registering with the all keywords caused handlers to be called later, even if they were registered with lower priorities.

Internationalization¶

Elgg 1.0+ departs from previous versions in that it uses a custom text array rather than gettext. This improves system performance and reliability of the translation system.

TODO: more plz

AMD¶

Overview¶

There are two JavaScript system in Elgg: the deprecated 1.8 system, and the newer AMD (Asynchronous Module Definition) compatible system introduced in 1.9.

This discusses the benefits of using AMD in Elgg.

Why AMD?¶

We have been working hard to make Elgg’s JavaScript more maintainable and useful. We made some strides in 1.8 with the introduction of the „elgg“ JavaScript object and library, but have quickly realized the approach we were taking was not scalable.

The size of JS on the web is growing quickly, and JS in Elgg is growing too. We want Elgg to be able to offer a solution that makes JS development as productive and maintainable as possible going forward.

The reasons to choose AMD are plenteous and well-documented. Let’s highlight just a few of the most relevant reasons as they relate to Elgg specifically.

1. Simplified dependency management¶

AMD modules load asynchronously and execute as soon as their dependencies are available, so this eliminates the need to specify „priority“ and „location“ when registering JS libs in Elgg. Also, you don’t need to worry about explicitly loading a module’s dependencies in PHP. The AMD loader (RequireJS in this case) takes care of all that hassle for you. It’s also possible have text dependencies with the RequireJS text plugin, so client-side templating should be a breeze.

2. AMD works in all browsers. Today.¶

Elgg developers are already writing lots of JavaScript. We know you want to write more. We cannot accept waiting 5-10 years for a native JS modules solution to be available in all browsers before we can organize our JavaScript in a maintainable way.

3. You do not need a build step to develop in AMD.¶

We like the edit-refresh cycle of web development. We wanted to make sure everyone developing in Elgg could continue experiencing that joy. Synchronous module formats like Closure or CommonJS just weren’t an option for us. But even though AMD doesn’t require a build step, it is still very build-friendly. Because of the define() wrapper, it’s possible to concatenate multiple modules into a single file and ship them all at once in a production environment. [1]

AMD is a battle-tested and well thought out module loading system for the web today. We’re very thankful for the work that has gone into it, and are excited to offer it as the standard solution for JavaScript development in Elgg starting with Elgg 1.9.

[1]	This is not currently supported by Elgg core, but we’ll be looking into it since reducing round-trips is critical for a good first-view experience, especially on mobile devices.

Security¶

Elgg’s approach to the various security issues common to all web applications.

Tipp

To report a potential vulnerability in Elgg, email security@elgg.org.

Contents

Passwords
Sessions
- Session fixation
- „Remember me“ cookie
Alternative authentication
HTTPS
XSS
CSRF / XSRF
Signed URLs
SQL Injection
Privacy
Hardening

Passwords ¶

Password validation ¶

The only restriction that Elgg places on a password is that it must be at least 6 characters long by default, though this may be changed in /elgg-config/settings.php. Additional criteria can be added by a plugin by registering for the registeruser:validate:password plugin hook.

Password hashing ¶

Passwords are never stored in plain text, only salted hashes produced with bcrypt. This is done via the standard password_hash() function. On older systems, the password-compat polyfill is used, but the algorithm is identical.

Elgg installations created before version 1.10 may have residual „legacy“ password hashes created using salted MD5. These are migrated to bcrypt as users log in, and will be completely removed when a system is upgraded to Elgg 3.0. In the meantime we’re happy to assist site owners to manually remove these legacy hashes, though it would force those users to reset their passwords.

Password throttling ¶

Elgg has a password throttling mechanism to make dictionary attacks from the outside very difficult. A user is only allowed 5 login attempts over a 5 minute period.

Password resetting ¶

If a user forgets his password, a new random password can be requested. After the request, an email is sent with a unique URL. When the user visits that URL, a new random password is sent to the user through email.

Sessions ¶

Elgg uses PHP’s session handling with custom handlers. Session data is stored in the database. The session cookie contains the session id that links the user to the browser. The user’s metadata is stored in the session including GUID, username, email address.

The session’s lifetime is controlled through the server’s PHP configuration and additionally through options in the /elgg-config/settings.php.

Session fixation ¶

Elgg protects against session fixation by regenerating the session id when a user logs in.

Alternative authentication ¶

Bemerkung

This section is very hand-wavy

To replace Elgg’s default user authentication system, a plugin could replace the default login action with its own. Better would be to register a PAM handler using register_pam_handler() which handles the authentication of the user based on the new requirements.

HTTPS ¶

Bemerkung

You must enable SSL support on your server for any of these techniques to work.

You can serve your whole site over SSL by changing the site URL to include „https“ instead of just „http“.

XSS ¶

Filtering is used in Elgg to make XSS attacks more difficult. The purpose of the filtering is to remove Javascript and other dangerous input from users.

Filtering is performed through the function filter_tags(). This function takes in a string and returns a filtered string. It triggers a validate, input plugin hook.

By default Elgg comes with the htmLawed filtering code. Developers can drop in any additional or replacement filtering code as a plugin.

The filter_tags() function is called on any user input as long as the input is obtained through a call to get_input(). If for some reason a developer did not want to perform the default filtering on some user input, the get_input() function has a parameter for turning off filtering.

CSRF / XSRF ¶

Elgg generates security tokens to prevent cross-site request forgery. These are embedded in all forms and state-modifying AJAX requests as long as the correct API is used. Read more in the Forms + Actions developer guide.

Signed URLs ¶

It’s possible to protect URLs with a unique signature. Read more in the Forms + Actions developer guide.

SQL Injection ¶

Elgg’s API sanitizes all input before issuing DB queries. Read more in the Database design doc.

Privacy ¶

Elgg uses an ACL system to control which users have access to various pieces of content. Read more in the Database design doc.

Hardening ¶

Site administrators can configure settings which will help with hardening the website. Read more in the Administrator guide Security.

Loggable¶

Loggable is an interface inherited by any class that wants events relating to its member objects to be saved to the system log. ElggEntity and ElggExtender both inherit Loggable.

Loggable defines several class methods that are used in saving to the default system log, and can be used to define your own (as well as for other purposes):

getSystemLogID() Return a unique identifier for the object for storage in the system log. This is likely to be the object’s GUID
getClassName() Return the class name of the object
getType() Return the object type
getSubtype() Get the object subtype
getObjectFromID($id) For a given ID, return the object associated with it

Database details¶

The default system log is stored in the system_log database table. It contains the following fields:

id - A unique numeric row ID
object_id - The GUID of the entity being acted upon
object_class - The class of the entity being acted upon (eg ElggObject)
object_type - The type of the entity being acted upon (eg object)
object_subtype - The subtype of the entity being acted upon (eg blog)
event - The event being logged (eg create or update)
performed_by_guid - The GUID of the acting entity (the user performing the action)
owner_guid - The GUID of the user which owns the entity being acted upon
access_id - The access restriction associated with this log entry
time_created - The UNIX epoch timestamp of the time the event took place

Contributor Guides¶

Participate in making Elgg even better.

Elgg is a community-driven project. It relies on the support of volunteers to succeed. Here are some ways you can help:

Writing Code¶

Understand Elgg’s standards and processes to get your changes accepted as quickly as possible.

Contents

License agreement
Pull requests
Coding Standards
Testing
Coding best practices
Deprecating APIs

License agreement ¶

By submitting a patch you are agreeing to license the code under a GPLv2 license and MIT license.

Pull requests ¶

Pull requests (PRs) are the best way to get code contributed to Elgg core. The core development team uses them even for the most trivial changes.

For new features, submit a feature request or talk to us first and make sure the core team approves of your direction before spending lots of time on code.

Checklists¶

Use these markdown checklists for new PRs on github to ensure high-quality contributions and help everyone understand the status of open PRs.

Bugfix PRs:

- [ ] Commit messages are in the standard format
- [ ] Includes regression test
- [ ] Includes documentation update (if applicable)
- [ ] Is submitted against the correct branch
- [ ] Has LGTM from at least one core developer

Feature PRs:

- [ ] Commit messages are in the standard format
- [ ] Includes tests
- [ ] Includes documentation
- [ ] Is submitted against the correct branch
- [ ] Has LGTM from at least two core developers

Choosing a branch to submit to¶

The following table assumes the latest stable release is 2.1.

Type of change	Branch to submit against
Security fix	Don’t! Email security@elgg.org for guidance.
Bug fix	1.12 (or 2.1 if the 1.12 fix is too complex)
Performance	2.x
Deprecation	2.x
Minor feature	2.x
Major feature	master
Has any breaking change	master

If you’re not sure which branch to submit against, just ask!

The difference between minor and major feature is subjective and up to the core team.

Commit message format¶

We require a particular format to allow releasing more often, and with improved changelogs and source history. Just follow these steps:

Start with the type by selecting the last category which applies from this list:
- docs - only docs are being updated
- chore - this include refactoring, code style changes, adding missing tests, Travis stuff, etc.
- perf - the primary purpose is to improve performance
- fix - this fixes a bug
- deprecate - the change deprecates any part of the API
- feature - this adds a new user-facing or developer feature
- security - the change affects a security issue in any way. Please do not push this commit to any public repo. Instead contact security@elgg.org.
E.g. if your commit refactors to fix a bug, it’s still a „fix“. If that bug is security-related, however, the type must be „security“ and you should email security@elgg.org before proceeding. When in doubt, make your best guess and a reviewer will provide guidance.
In parenthesis, add the component, a short string which describes the subsystem being changed.

Some examples: views, i18n, seo, a11y, cache, db, session, router, <plugin_name>.

Add a colon, a space, and a brief summary of the changes, which will appear in the changelog.

No line may exceed 100 characters in length, so keep your summary concise.

Good summary	Bad summary (problem)
page owners see their own owner blocks on pages	bug fix (vague)
bar view no longer dies if ‚foo‘ not set	updates views/default/bar.php so bar view no longer… (redundant info)
narrows river layout to fit iPhone	alters the river layout (vague)
elgg_foo() handles arrays for $bar	in elgg_foo() you can now pass an array for $bar and the function will… (move detail to description)
removes link color from comments header in river	fixes db so that… (redundant info)
requires non-empty title when saving pages	can save pages with no title (confusingly summarizes old behavior)

(recommended) Skip a line and add a description of the changes. Include the motivation for making them, any info about back or forward compatibility, and any rationale of why the change had to be done a certain way. Example:

We speed up the Remember Me table migration by using a single INSERT INTO … SELECT query instead of row-by-row. This migration takes place during the upgrade to 1.9.

Unless your change is trivial/obvious, a description is required.
If the commit resolves a GitHub issue, skip a line and add Fixes # followed by the issue number. E.g. Fixes #1234. You can include multiple issues by separating with commas.

GitHub will auto-close the issue when the commit is merged. If you just want to reference an issue, use Refs # instead.

When done, your commit message will have the format:

type(component): summary

Optional body
Details about the solution.
Opportunity to call out as breaking change.

Closes/Fixes/Refs #123, #456, #789

Here is an example of a good commit message:

perf(upgrade): speeds up migrating remember me codes

We speed up the Remember Me table migration by using a single INSERT INTO ... SELECT query instead of row-by-row.
This migration takes place during the upgrade to 1.9.

Fixes #6204

To validate commit messages locally, make sure .scripts/validate_commit_msg.php is executable, and make a copy or symlink to it in the directory .git/hooks/commit-msg.

chmod u+x .scripts/validate_commit_msg.php
ln -s .scripts/validate_commit_msg.php .git/hooks/commit-msg/validate_commit_msg.php

Rewriting commit messages¶

If your PR does not conform to the standard commit message format, we’ll ask you to rewrite it.

To edit just the last commit:

Amend the commit: git commit --amend (git opens the message in a text editor).
Change the message and save/exit the editor.
Force push your branch: git push -f your_remote your_branch (your PR with be updated).
Rename the PR title to match

Otherwise you may need to perform an interactive rebase:

Rebase the last N commits: git rebase -i HEAD~N where N is a number. (Git will open the git-rebase-todo file for editing)
For the commits that need to change, change pick to r (for reword) and save/exit the editor.
Change the commit message(s), save/exit the editor (git will present a file for each commit that needs rewording).
git push -f your_remote your_branch to force push the branch (updating your PR).
Rename the PR title to match

Coding Standards ¶

Elgg uses set of standards that are based partially on PEAR and PSR2 standards. You can view the ruleset in vendor/elgg/sniffs/elgg.xml.

To check your code for standard violations (provided you have installed Elgg with dev dependencies), run:

phpcs --standard=vendor/elgg/sniffs/elgg.xml -s path/to/dir/to/check

To automatically fix fixable violations, run:

phpcbf --standard=vendor/elgg/sniffs/elgg.xml path/to/dir/to/fix

To check core directories, you can use shortcut composer lint and composer lint-fixer.

Testing ¶

Elgg has automated tests for both PHP and JavaScript functionality. All new contributions are required to come with appropriate tests.

Siehe auch

Writing tests

General guidelines¶

Break tests up by the behaviors you want to test and use names that describe the behavior. E.g.:

Not so good: One big method testAdd().
Better: Methods testAddingZeroChangesNothing and testAddingNegativeNumberSubtracts

Strive for componentized designs that allow testing in isolation, without large dependency graphs or DB access. Injecting dependencies is key here.

PHP Tests¶

PHPUnit¶

Located in engine/tests/phpunit, this is our preferred test suite. It uses no DB access, and has only superficial access to the entities API.

We encourage you to create components that are testable in this suite if possible.
Consider separating storage from your component so at least business logic can be tested here.
Depend on the Elgg\Filesystem\* classes rather than using PHP filesystem functions.

Testing interactions between services¶

Ideally your tests would construct your own isolated object graphs for direct manipulation, but this isn’t always possible.

If your test relies on Elgg’s Service Provider (_elgg_services() returns a Elgg\Di\ServiceProvider), realize that it maintains a singleton instance for most services it hands out, and many services keep their own local references to these services as well.

Due to these local references, replacing services on the SP within a test often will not have the desired effect. Instead, you may need to use functionality baked into the services themselves:

The events and hooks services have methods backup() and restore().
The logger service has methods disable() and enable().

Jasmine Tests¶

Test files must be named *Test.js and should go in either js/tests/ or next to their source files in views/default/**.js. Karma will automatically pick up on new *Test.js files and run those tests.

Test boilerplate¶

define(function(require) {
        var elgg = require('elgg');

        describe("This new test", function() {
                it("fails automatically", function() {
                        expect(true).toBe(false);
                });
        });
});

Running the tests¶

Elgg uses Karma with Jasmine to run JS unit tests.

You will need to have nodejs and yarn installed.

First install all the development dependencies:

yarn

Run through the tests just once and then quit:

yarn test

You can also run tests continuously during development so they run on each save:

karma start js/tests/karma.conf.js

Debugging JS tests¶

You can run the test suite inside Chrome dev tools:

yarn run chrome

This will output a URL like http://localhost:9876/.

Open the URL in Chrome, and click „Debug“.
Open Chrome dev tools and the Console tab.
Reload the page.

If you alter a test you’ll have to quit Karma with Ctrl-c and restart it.

Coding best practices ¶

Make your code easier to read, easier to maintain, and easier to debug. Consistent use of these guidelines means less guess work for developers, which means happier, more productive developers.

General coding¶

Don’t Repeat Yourself¶

If you are copy-pasting code a significant amount of code, consider whether there’s an opportunity to reduce duplication by introducing a function, an additional argument, a view, or a new component class.

E.g. If you find views that are identical except for a single value, refactor into a single view that takes an option.

Note: In a bugfix release, some duplication is preferrable to refactoring. Fix bugs in the simplest way possible and refactor to reduce duplication in the next minor release branch.

Embrace SOLID and GRASP¶

Use these principles for OO design to solve problems using loosely coupled components, and try to make all components and integration code testable.

Whitespace is free¶

Don’t be afraid to use it to separate blocks of code. Use a single space to separate function params and string concatenation.

Variable names¶

Use self-documenting variable names. $group_guids is better than $array.

Avoid double-negatives. Prefer $enable = true to $disable = false.

Interface names¶

Use the pattern Elgg\{Namespace}\{Name}.

Do not include an I prefix or an Interface suffix.

We do not include any prefix or suffix so that we’re encouraged to:

name implementation classes more descriptively (the „default“ name is taken).

type-hint on interfaces, because that is the shortest, easiest thing to do.

Name implementations like Elgg\{Namespace}\{Interface}\{Implementation}.

Functions¶

Where possible, have functions/methods return a single type. Use empty values such as array(), "", or 0 to indicate no results.

Be careful where valid return values (like "0") could be interpreted as empty.

Functions not throwing an exception on error should return false upon failure.

Bemerkung

Particularly low-level, non-API functions/methods (e.g. entity_row_to_elggstar), which should not fail under normal conditions, should throw instead of returning false.

Functions returning only boolean should be prefaced with is_ or has_ (eg, elgg_is_logged_in(), elgg_has_access_to_entity()).

Ternary syntax¶

Acceptable only for single-line, non-embedded statements.

Minimize complexity¶

Minimize nested blocks and distinct execution paths through code. Use Return Early to reduce nesting levels and cognitive load when reading code.

Use comments effectively¶

Good comments describe the „why.“ Good code describes the „how.“ E.g.:

Bad:

// increment $i only when the entity is marked as active.
foreach ($entities as $entity) {
        if ($entity->active) {
                $i++;
        }
}

Good:

// find the next index for inserting a new active entity.
foreach ($entities as $entity) {
        if ($entity->active) {
                $i++;
        }
}

Always include a comment if it’s not obvious that something must be done in a certain way. Other developers looking at the code should be discouraged from refactoring in a way that would break the code.

// Can't use empty()/boolean: "0" is a valid value
if ($str === '') {
    register_error(elgg_echo('foo:string_cannot_be_empty'));
    forward(REFERER);
}

Commit effectively¶

Err on the side of atomic commits which are highly focused on changing one aspect of the system.
Avoid mixing in unrelated changes or extensive whitespace changes. Commits with many changes are scary and make pull requests difficult to review.
Use visual git tools to craft highly precise and readable diffs.

Include tests¶

When at all possible include unit tests for code you add or alter.

Keep bugfixes simple¶

Avoid the temptation to refactor code for a bugfix release. Doing so tends to introduce regressions, breaking functionality in what should be a stable release.

PHP guidelines¶

These are the required coding standards for Elgg core and all bundled plugins. Plugin developers are strongly encouraged to adopt these standards.

Developers should first read the PSR-2 Coding Standard Guide.

Elgg’s standards extend PSR-2, but differ in the following ways:

Indent using one tab character, not spaces.
Opening braces for classes, methods, and functions must go on the same line.
If a line reaches over 100 characters, consider refactoring (e.g. introduce variables).
Compliance with PSR-1 is encouraged, but not strictly required.

Documentation¶

Include PHPDoc comments on functions and classes (all methods; declared properties when appropriate), including types and descriptions of all parameters.
In lists of @param declarations, the beginnings of variable names and descriptions must line up.
Annotate classes, methods, properties, and functions with @internal unless they are intended for public use, are already of limited visibility, or are within a class already marked as @internal.
Use // or /* */ when commenting.
Use only // comments inside function/method bodies.

Naming¶

Use underscores to separate words in the names of functions, variables, and properties. Method names are camelCase.
Names of functions for public use must begin with elgg_.
All other function names must begin with _elgg_.
Name globals and constants in ALL_CAPS (ACCESS_PUBLIC, $CONFIG).

Miscellaneous¶

For PHP requirements, see composer.json.

Do not use PHP shortcut tags <? or <%. It is OK to use <?= since it is always enabled as of PHP 5.4.

When creating strings with variables:

use double-quoted strings
wrap variables with braces only when necessary.

Bad (hard to read, misuse of quotes and {}s):

echo 'Hello, '.$name."!  How is your {$time_of_day}?";

Good:

echo "Hello, $name!  How is your $time_of_day?";

Remove trailing whitespace at the end of lines. An easy way to do this before you commit is to run php .scripts/fix_style.php from the installation root.

Value validation¶

When working with user input prepare the input outside of the validation method.

Bad:

function validate_email($email) {
        $email = trim($email);

        // validate
}

$email = get_input($email);

if (validate_email($email)) {
        // the validated email value is now out of sync with an actual input
}

Good:

function validate_email($email) {
        // validate
}

$email = get_input($email);
$email = trim($email);

if (validate_email($email)) {
        // green light
}

Use exceptions¶

Do not be afraid to use exceptions. They are easier to deal with than mixed function output:

Bad:

/**
* @return string|bool
*/
function validate_email($email) {
        if (empty($email)) {
                return 'Email is empty';
        }

        // validate

        return true;
}

Good:

/**
* @return void
* @throw InvalidArgumentException
*/
function validate_email($email) {
        if (empty($email)) {
                throw new InvalidArgumentException('Email is empty');
        }

        // validate and throw if invalid
}

Documenting return values¶

Do not use @return void on methods that return a value or null.

Bad:

/**
* @return bool|void
*/
function validate_email($email) {
        if (empty($email)) {
                return;
        }

        // validate

        return true;
}

Good:

/**
* @return bool|null
*/
function validate_email($email) {
        if (empty($email)) {
                return null;
        }

        // validate

        return true;
}

CSS guidelines¶

Save the css in files with a .css extension.

Use shorthand where possible¶

Bad:

background-color: #333333;
background-image:  url(...);
background-repeat:  repeat-x;
background-position:  left 10px;
padding: 2px 9px 2px 9px;

Good:

background: #333 url(...) repeat-x left 10px;
padding: 2px 9px;

Use hyphens, not underscores¶

Bad:

.example_class {}

Good:

.example-class {}

Bemerkung

You should prefix your ids and classnames with text that identifies your plugin.

One property per line¶

Bad:

color: white;font-size: smaller;

Good:

color: white;
font-size: smaller;

Property declarations¶

These should be spaced like so: property: value;

Bad:

color:value;
color :value;
color : value;

Good:

color: value;

Vendor prefixes¶

Group vendor-prefixes for the same property together

Longest vendor-prefixed version first

Always include non-vendor-prefixed version

Put an extra newline between vendor-prefixed groups and other properties

Bad:

-moz-border-radius: 5px;
border: 1px solid #999999;
-webkit-border-radius: 5px;
width: auto;

Good:

border: 1px solid #999999;

-webkit-border-radius: 5px;
-moz-border-radius: 5px;
border-radius: 5px;

width: auto;

Group subproperties¶

Bad:

background-color: white;
color: #0054A7;
background-position: 2px -257px;

Good:

background-color: white;
background-position: 2px -257px;
color: #0054A7;

Javascript guidelines¶

Same formatting standards as PHP apply.

All functions should be in the elgg namespace.

Function expressions should end with a semi-colon.

elgg.ui.toggles = function(event) {
        event.preventDefault();
        $(target).slideToggle('medium');
};

Deprecating APIs ¶

Occasionally functions and classes must be deprecated in favor of newer replacements. Since 3rd party plugin authors rely on a consistent API, backward compatibility must be maintained, but will not be maintained indefinitely as plugin authors are expected to properly update their plugins. In order to maintain backward compatibility, deprecated APIs will follow these guidelines:

Minor version (1.x) that deprecates an API must include a wrapper function/class (or otherwise appropriate means) to maintain backward compatibility, including any bugs in the original function/class. This compatibility layer uses elgg_deprecated_notice('...', '1.11') to log that the function is deprecated.
The next major revision (2.0) removes the compatibility layer. Any use of the deprecated API should be corrected before this.

Database¶

Contributing database schema changes

Contents

Database Migrations

Database Migrations ¶

Elgg uses Phinx to manage the database migrations.

Create a migration¶

To create a new migration run the following in your console:

vendor/bin/phinx create -c engine/conf/migrations.php MigrationClassName

This will generate a timestamped skeleton migration in engine/schema/migrations/. Follow Phinx documentation to call the necessary methods to modify the database tables.

Executing a migration¶

Migrations are executed every time your run upgrade.php. If you would like to execute migrations manually, you can do so via the command line:

// When Elgg is the root project
vendor/bin/phinx migrate -c engine/conf/migrations.php

// When Elgg is installed as a Composer dependency
vendor/bin/phinx migrate -c vendor/elgg/elgg/engine/conf/migrations.php

Check Phinx documentation for additional flags that allow you to run a single migration or a set of migrations within a time range.

Writing Documentation¶

New documentation should fit well with the rest of Elgg’s docs.

Contents

Testing docs locally
Follow the existing document organization
Use „Elgg“ in a grammatically correct way
Avoid first person pronouns
Eliminate fluff
Prefer absolute dates over relative ones
Do not remind the reader to contribute

Testing docs locally ¶

Elgg has a grunt script that automatically builds the docs, opens them in a browser window, and automatically reloads as you make changes (the reload takes just a few seconds). You need yarn and sphinx installed to be able to use these scripts.

cd path/to/elgg/
yarn
grunt

It’s that easy! Grunt will continue running, watching the docs for changes and automatically rebuilding.

Follow the existing document organization ¶

The current breakdown is not necessarily the One True Way to organize docs, but consistency is better than randomness.

intro/*¶

This is everything that brand new users need to know (installation, features, license, etc.)

admin/*¶

Guides for administrators. Task-oriented.

guides/*¶

API guides for plugin developers. Cookbook-style. Example heavy. Code snippet heavy. Broken down by services (actions, i18n, routing, db, etc.). This should only discuss the public API and its behavior, not implementation details or reasoning.

design/*¶

Design docs for people who want to get a better understanding of how/why core is built the way it is. This should discuss internal implementation details of the various services, what tradeoffs were made, and the reasoning behind the final decision. Should be useful for people who want to contribute and for communication b/w core devs.

contribute/*¶

Contributors guides for the various ways people can participate in the project.

appendix/*¶

More detailed/meta/background information about the project (history, roadmap, etc.)

Use „Elgg“ in a grammatically correct way ¶

Elgg is not an acronym, so writing it in all caps (ELGG or E-LGG) is incorrect. Please don’t do this.

In English, Elgg does not take an article when used as a noun. Here are some examples to emulate:

„I’m using Elgg to run my website“
„Install Elgg to get your community online“

When used as an adjective, the article applies to the main noun, so you should use one. For example:

„Go to the Elgg community website to get help.“
„I built an Elgg-based network yesterday“

This advice may not apply in languages other than English.

Avoid first person pronouns ¶

Refer to the reader as „you“. Do not include yourself in the normal narrative.

Before:

When we’re done installing Elgg, we’ll look for some plugins!

After:

When you’re done installing Elgg, look for some plugins!

To refer to yourself (avoid this if possible), use your name and write in the third person. This clarifies to future readers/editors whose opinions are being expressed.

Before:

I think the best way to do X is to use Y.

After:

Evan thinks the best way to do X is to use Y.

Eliminate fluff ¶

Before:

If you want to use a third-party javascript library within the Elgg framework, you should take care to call the elgg_register_js function to register it.

After:

To use a third-party javascript library, call elgg_register_js to register it.

Prefer absolute dates over relative ones ¶

It is not easy to tell when a particular sentence or paragraph was written, so relative dates quickly become meaningless. Absolute dates also give the reader a good indication of whether a project has been abandoned, or whether some advice might be out of date.

Before:

Recently the foo was barred. Soon, the baz will be barred too.

After:

Recently (as of September 2013), the foo was barred. The baz is expected to be barred by October 2013.

Do not remind the reader to contribute ¶

Focus on addressing only the topic at hand. Constant solicitation for free work is annoying and makes the project look needy. If people want to contribute to the project, they can visit the contributor guide.

Internationalizing documentation¶

When you change documentation, remember to update the documentation translation templates before you commit:

cd docs/
make gettext

For more information, see http://www.sphinx-doc.org/en/stable/intl.html#translating-with-sphinx-intl

Special attention¶

When translating the documentation be aware of special syntax in the documentation files.

Translating links¶

Translate text in anonymous links (e.g., `pronunciation`__), but maintain the order of all anonymous links in a single block. If there are two anonymous links within a single block for translation, they must not be rearranged relative to each other.

Translate the text of named links (e.g., `demo site`_) but only if you maintain the name using the correct rST syntax. In this case that would be `translation of "demo site" <demo site_>`_.

Do NOT translate¶

Anything between pipe characters should not be translated (e.g., master).

Code, unless it’s a comment in the code.

Translations¶

Translations multiply the impact that Elgg can have by making it accessible to a larger percentage of the world.

The community will always be indebted to those of you who work hard to provide high quality translations for Elgg’s UI and docs.

Transifex¶

All translation for the Elgg project is organized through Transifex.

https://www.transifex.com/organization/elgg

Plugin authors are encouraged to coordinate translations via Transifex as well so the whole community can be unified and make it really easy for translators to contribute to any plugin in the Elgg ecosystem.

Pulling translations¶

The translations made in Transifex need to be periodically pulled into the Elgg code repository. This can be done with the script .scripts/languages.php bundled within Elgg’s source code.

Prerequisites for running the script are:

Access to command line
Git
Transifex CLI tool

The script will do the following steps:

Create a new git branch named {branch}_i18n_{timestamp}
Pull translations for all languages that have 95% of the strings translated
Remove possible invalid language codes
Commit the changes to the branch

After this you must push the branch to Github and make a new Pull request.

For example if you want to pull the translations for the 3.x branch, run the following commands:

php .scripts/languages.php 3.x
git push -u your_fork 3.x_i18n_1515151617

Run the command without parameters to get more detailed information of the usage.

Transifex configuration¶

The configuration for Transifex can be found from Elgg’s source code in the file .tx/config.

This file defines:

The Transifex project associated with Elgg’s major version
The location of all the files that have translatable content

Read the Transifex documentation for further details.

New major Elgg version¶

Every major version of Elgg must have its own project in Transifex. This way we can make sure that strings added and removed between versions do not conflict with each other. For example a translation key removed in Elgg 3 should not get removed from translations made for Elgg 2. Respectfully a new string added only to Elgg 3 should not be included in the translations meant for Elgg 2.

The process of setting up a new major version is:

Pull latest translations from Transifex to the previous major version

Merge the git branch of the previous version to the new to make sure all the latest translation keys are present

Create a new Transifex project to https://www.transifex.com/elgg/

Update .tx/config file in the development branch of the new major version

Update the configuration to point to the new Transifex project

Remove configuration of removed plugins

Add configuration for new plugins
Push the translation sources to the new Transifex project with the command:
tx push -s
Copy the new configuration file temporarily (do not commit) to the previous major version, and push the existing translations from it to the new project:
tx push -t -f --no-interactive

Later, once the dedicated branch (e.g. 3.x has been created for the major version, configure Transifex to fetch new translation keys from it automatically in https://www.transifex.com/elgg/elgg-core-3/content/. This way you don’t have to repeat step 5 manually every time new translation keys are added.

It is important to always have a n.x branch besides the branches meant for specific minor versions (n.1, n.2, etc.). This way the URLs of the auto-update sources do not have to be updated every time a new minor branch is created.

Reporting Issues¶

Report bugs and features requests to https://github.com/Elgg/Elgg/issues. See below for guidelines.

DISCLAIMERS¶

Achtung

Security issues should be reported to security @ elgg . org! Please do not post any security issues on github!!

Bemerkung

Support requests belong on the community site. Tickets with support requests will be closed.

Wichtig

We cannot make any guarantees as to when your ticket will be resolved.

Bug reports¶

Before submitting a bug report:

Search for an existing ticket on the issue you’re having. Add any extra info there.
Verify the problem is reproducible
- On the latest version of Elgg
- With all third-party plugins disabled

Good bug report checklist:

Expected behavior and actual behavior
Clear steps to reproduce the problem
The version of Elgg you’re running
Browsers affected by this problem

Feature requests¶

Before submitting a feature request:

Check the community site for a plugin that has the features you need.
Consider if you can develop a plugin that does what you need.
Search through the closed tickets to see if someone else suggested the same feature, but got turned down. You’ll need to be able to explain why your suggestion should be considered this time.

Good feature request checklist:

Detailed explanation of the feature
Real-life use-cases
Proposed API

Becoming a Financial Supporter¶

All funds raised via the Elgg supporters network go directly into:

Elgg core development
Infrastructure provision (elgg.org, github, etc.)

It is a great way to help with Elgg development!

Benefits¶

For only $50 per year for individuals or $150 per year for organizations, you can get listed as a supporter on our supporters page. Elgg supporters are listed there unless they request not to be.

Supporters are able to put this official logo on their site if they wish:

Disclaimer¶

We operate a no refund policy on supporter subscriptions. If you would like to withdraw your support, go to PayPal and cancel your subscription. You will not be billed the following year.

Being an Elgg Supporter does not give an individual or organization the right to impersonate, trade as or imply they are connected to the Elgg project. They can, however, mention that they support the Elgg project.

If you have any questions about this disclaimer, email info@elgg.org.

We reserve the right to remove or refuse a listing without any prior warning at our complete discretion. There is no refund policy.

If there is no obvious use of Elgg, your site will be linked to with „nofollow“ set.

Sign up¶

If you would like to become an Elgg supporter:

read the disclaimer above

on the supporters page, subscribe via PayPal

send an email to info@elgg.org with:

the date you subscribed

your name (and organization name, if applicable)

your website

your Elgg community profile

Once all the details have been received, we will add you to the appropriate list. Thanks for your support!

Adding a Service to Elgg¶

The services guide has general information about using Elgg services.

To add a new service object to Elgg:

Annotate your class as @internal.
Open the class Elgg\Di\ServiceProvider.
Add a @property-read annotation for your service at the top. This allows IDEs and static code analyzers to understand the type of the property.
To the constructor, add code to tell the service provider what to return. See the class Elgg\Di\DiContainer for more information on how Elgg’s DI container works.

At this point your service will be available from the service provider object, but will not yet be accessible to plugins.

Inject your dependencies¶

Design your class constructor to ask for the necessary dependencies rather than creating them or using _elgg_services(). The service provider’s setFactory() method provides access to the service provider instance in your factory method.

Here’s an example of a foo service factory, injecting the config and db services into the constructor:

// in Elgg\Di\ServiceProvider::__construct()

$this->setFactory('foo', function (ServiceProvider $c) {
    return new Elgg\FooService($c->config, $c->db);
});

The full list of internal services can be seen in the @property-read declarations at the top of Elgg\Di\ServiceProvider.

Warnung

Avoid performing work in your service constructor, particularly if it requires database queries. Currently PHPUnit tests cannot perform them.

Making a service part of the public API¶

If your service is meant for use by plugin developers:

Make an interface Elgg\Services\<Name> that contains only those methods needed in the public API.
Have your service class implement that interface.
For methods that are in the interface, move the documentation to the interface. You can simply use {@inheritdoc} in the PHPDocs of the concrete class methods.
Document your service in docs/guides/services.rst (this file).
Open the PHPUnit test Elgg\ApplicationTest and add your service key to the $names array in testServices().
Open the class Elgg\Application.
Add @property-read declaration to document your service, but use your interface as the type, not your service class name.
Add your service key to the array in the $public_services property, e.g. 'foo' => true,

Now your service will be available via property access on the Elgg\Application instance:

// using the public foo service
$three = elgg()->foo->add(1, 2);

Bemerkung

For examples, see the config service, including the interface Elgg\Services\Config and the concrete implementation Elgg\Config.

Service Life Cycle and Factories¶

By default, services registered on the service provider are „shared“, meaning the service provider will store the created instance for the rest of the request, and serve that same instance to all who request the property.

If you need developers to be able to construct objects that are pre-wired to Elgg services, you may need to add a public factory method to Elgg\Application. Here’s an example that returns a new instance using internal Elgg services:

public function createFoo($bar) {
    $logger = $this->services->logger;
    $db = $this->services->db;
    return new Elgg\Foo($bar, $logger, $db);
}

Writing tests¶

Contents

Vision
Running Tests
Motivation
Strategy

Vision ¶

We want to make manual testing unnecessary for core developers, plugin authors, and site administrators by promoting and enabling fast, automated testing at every level of the Elgg stack.

We look forward to a world where the core developers do not need to do any manual testing to verify the correctness of code contributed to Elgg. Similarly, we envision a world where site administrators can upgrade and install new plugins with confidence that everything works well together.

Running Tests ¶

Elgg Core Test Suite ¶

Currently our tests are split in two pieces:

PHPUnit tests are located in /tests/phpunit – these are split between unit tests and integration tests.

Since we have a phpunit.xml configuration at the root of Elgg, testing should be as easy as:

git clone http://github.com/Elgg/Elgg
cd Elgg
phpunit

Plugin tests ¶

Ideally plugins are configured in such a way that they can be unit-tested much like Elgg core. Plugin developers are free to implement their own methods for unit testing, but we encourage everyone to make it as easy as Elgg core:

git clone http://github.com/developer/elgg-plugin plugin
cd plugin
phpunit

End-to-end tests ¶

Since Elgg plugins have so much power to override, filter, and modify Elgg’s and other plugins‘ behavior, it’s important to be able to run end-to-end tests on a staging server with your final configuration before deploying to production.

Bemerkung

ToDo: Make it easy to run all Elgg integration and acceptance tests from the admin area given the current plugin configuration. (without worrying about database corruption!)

Motivation ¶

Briefly, the wins we expect from testing are:

Increased confidence in the system.
More freedom to refactor.
Built-in, up-to-date documentation.

We love community contributions, but in order to maintain stability we cannot accept outside contributions without first verifying their correctness. By promoting automated testing, the core developers can avoid the hassle of manual verification before accepting patches. It also means that external developers don’t have to spend time earning trust with the core team. If a patch comes in and has tests to verify it, then we can be confident it works without worrying about the reputation of the contributor.

Note that these benefits can also extend to the plugins repository. Site owners are encouraged to „test plugins thoroughly“ before deploying them on a production site. As of March 2013, this translates to manually verifying all the features that the plugin promises to offer. But Elgg provides a huge number of features, and it’s not reasonable to test for all of them on every browser you want to support on every device you want to support. But what if plugin developers could write tests for their plugins and site owners could just run the tests for all installed plugins to verify the functionality is maintained? Then they wouldn’t be limited to just picking plugins from „trusted“ developers or „stable“ releases. They could see that, indeed, nothing broke when they upgraded that critical plugin from 1.3 to 2.5, and push the upgrade to production with confidence.

The reason this isn’t happening today is because Elgg itself is not easily testable at this level yet. We want to change that.

Strategy ¶

We have several guiding principles that we think will be helpful in bringing our vision into reality.

In short, we are advocating:

Continuous integration – if Travis isn’t happy, we’re not happy
Dependency injection – For creating highly testable, modular code
BDD – Tests should verify features and provide documentation, not rehash the Class API

Continuous Integration ¶

We run all of our tests on Travis CI so that we can get real time feedback on the correctness of incoming pull requests and development as it progresses. If Travis isn’t happy, we don’t commit to the repo. This empowers us to merge pull requests in at a rapid pace, so long as they pass the tests. It also allows us to reject pull requests without detailed investigation if they do not pass the tests. We can get past the „does it work or not“ question and talk about the things that humans need to talk about: API design, usefulness to the project, whether it belongs in core or a plugin, etc. We want as many features as possible provided by Elgg core to be verified automatically by tests running on Travis.

Dependency Injection ¶

In order to maximize testability, all dependencies need to be explicit. Global functions, Singletons, and service locators are death for testability because it’s impossible to tell what dependencies are hiding under the covers, and it’s even harder to mock out those dependencies. Mocking is critical because you want your unit tests to test only one class at a time. Test failures in a TestCase should not result due to brokenness in a dependency; test failures should only indicate brokenness in the class under test. This makes everything much easier to debug. As of March 2013, most of Elgg still assumes and uses global state, and that has made Elgg and Elgg plugins historically very difficult to test. Fortunately we are moving in the opposite direction now, and a lot of work in Elgg 1.9 has gone into refactoring core components to be more dependency injectable. We are already reaping the benefits from that effort.

Behavior-Driven Development ¶

For us this means we name tests for features rather than methods. When you test for features, you are encouraged to write fewer, smaller, logical tests. When a test fails, we can know exactly what feature is compromised. Furthermore, when naming your tests for features, the list of tests provides documentation on what features the system supports. Documentation is something that is typically very troublesome to keep up to date, but when documentation and verification are one and the same, it becomes very easy to keep the documentation up to date.

Consider these two test methods:

testRegister()
testCanRegisterFilesAsActionHandlers()

From just looking at the names, testRegister tells you that the class under test probably has a method named register. If this test passes, it presumably verifies that it is behaving correctly, but doesn’t tell you what correct behavior entails, or what the original author of the test was intending to verify. If that method has multiple correct uses that you need to test for, this terse naming convention also encourages you to write a very long test which tests for all conditions and features of said method. Test failure could be caused by any one of those uses being compromised, and it will take more time to figure out where the true problem lies.

On the other hand, testCanRegisterFilesAsActionHandlers tells you that there are these things called „actions“ that need to be „handled“ and that files can be registered as valid handlers for actions. This introduces newcomers to project terminology and communicates clearly the intent of the test to those already familiar with the terminology.

For a good example of what we’re looking for, check out /tests/phpunit/Elgg/ViewServiceTest.php

Core tasks¶

Certain tasks surrounding Elgg are reserved for the core developer as they require special permissions. The guides below show the workflow for these actions.

Moving a plugin to its own repository¶

Contents

Plugin extraction steps
Elgg core cleanup

Plugin extraction steps ¶

Move the code to its own repository ¶

Follow the GitHub guide Splitting a subfolder out into a new repository. This will make sure that the commit history is preserved.

Dependencies ¶

If the plugin has dependencies on any external libraries, make sure these dependencies are managed. For example if a PHP library is required which comes bundled with Elgg core, make sure to add it to the composer.json of this plugin as you can’t rely on Elgg core keeping the library.

Commit the code ¶

During the GitHub guide a new repository is created for the plugin you’re trying to move.

Since an attemp was already made to extract some of the plugins to their own repository maybe the repository already exists.

If the repository didn’t exist for the plugin, make sure you create it under the Elgg organisation.

If the repository already exists, the best way to update the code would be by a Pull Request. This will however probably fail because of a difference in how the repository was first created (as discussed in this GitHub issue).

The initial repositories where created with

git subtree split

and the guide calls for

git filter-branch --prune-empty --subdirectory-filter

This will leave a difference in the commits which GitHub is unable to resolve. In that case you’ll have to force push the changes to the existing Elgg plugin repository.

Warnung

Since this will override all the history in the plugin repository, make sure you know this is what you want to do.

Packagist ¶

Make sure the composer.json of the plugin contains all the relevant information. Here is an example:

{
        "name": "elgg/<name of the repository>",
        "description": "<a description of the plugin>",
        "type": "elgg-plugin",
        "keywords": ["elgg", "plugin"],
        "license": "GPL-2.0-only",
        "support": {
                "source": "https://github.com/elgg/<name of the repository>",
                "issues": "https://github.com/elgg/<name of the repository>/issues"
        },
        "require": {
                "composer/installers": ">=1.0.8"
        },
        "conflict": {
                "elgg/elgg": "< <minimal Elgg required version>"
        }
}

The conflict rule is there to help prevent the installation of this plugin in an unsupported Elgg version.

Add the repository to Packagist, for the existing repositories this was already done. Make sure Packagist is updated correctly with all the commits.

Tag a release ¶

In order for Composer to be able to cache the plugin for faster installation, a release has to be made on the repository. Probably the first version that needs to be tagged is the same version as mentioned in the manifest.xml. After this development can begin, following the Semver versioning scheme.

Translations ¶

If the translations for the plugin need to be managed by Transifex, add the plugin to Transifex.

Elgg core cleanup ¶

Now that the plugin has been moved to it’s own repository, it’s time to make a Pull Request on Elgg core to remove the original code.

Remove the plugin ¶

Delete the mod folder for the plugin
Search for the plugin name in core to find any references which also need to be removed (eg. old docs, special tests, etc.)

Translations ¶

Since the plugin no longer is part of Elgg core, make sure the configuration of Transifex no longer contains the plugin.

Bundled ¶

If the plugin still comes bundled with the release of a new Elgg version, make sure to add the plugin to the composer.json.

Composer ¶

Check the core composer dependencies if requirements that were specific for the removed plugin can also be removed in the core dependencies.

Documentation ¶

Add a mention in the Upgrade Notes documentation that the plugin was removed from Elgg core.

Release Process Workflow¶

Release a new version of Elgg.

This is the process the core team follows for making a new Elgg release. We have published this information in the spirit of openness, and to streamline onboarding of new team members.

Contents

Requirements
Merge commits up from lower branches
First new stable minor/major release
Prepare the release
Tag the release
Update the website
Make the announcement

Requirements ¶

SSH access to elgg.org
Commit access to http://github.com/Elgg/Elgg
Admin access to https://elgg.org/
Access to Twitter account
Node.js and Yarn installed
Sphinx installed (easy_install sphinx && easy_install sphinx-intl)
Transifex client installed (easy_install transifex-client)
Transifex account with access to Elgg project

Merge commits up from lower branches ¶

Determine the LTS branch. We need to merge any new commits there up through the other branches.

For each branch¶

Check out the branch, make sure it’s up to date, and make a new work branch with the merge. E.g. here we’re merging 1.12 commits into 2.0:

git checkout 2.0
git pull
git checkout -b merge112
git merge 1.12

Bemerkung

If already up-to-date (no commits to merge), we can stop here for this branch.

If there are conflicts, resolve them, git add ., and git merge.

Make a PR for the branch and wait for automated tests and approval by other dev(s).

git push -u my_fork merge112

Once merged, we would repeat the process to merge 2.0 commits into 2.1.

First new stable minor/major release ¶

Update the Support policy to include the new minor/major release date and fill in the blanks for the previous release.

Update the README.md file badges to point to the correct new release numbers.

Prepare the release ¶

Bring your local git clone up to date.

Merge latest commits up from lowest supported branch.

Visit https://github.com/Elgg/Elgg/compare/<new>...<old> and submit the PR if there is anything that needs to be merged up.

Install the prerequisites:

yarn install elgg-conventional-changelog
easy_install sphinx
easy_install sphinx-intl
easy_install transifex-client

Bemerkung

On Windows you need to run these command in a console with admin privileges

Run the release.php script. For example, to release 1.12.5:

git checkout 1.12
php .scripts/release.php 1.12.5

This creates a release-1.12.5 branch in your local repo.

Next, manually browse to the /admin/site_settings page and verify it loads. If it does not, a language file from Transifex may have a PHP syntax error. Fix the error and amend your commit with the new file:

# only necessary if you fixed a language file
git add .
git commit --amend

Next, submit a PR via GitHub for automated testing and approval by another developer:

git push your-remote-fork release-1.12.5

Tag the release ¶

Once approved and merged, tag the release:

git checkout release-${version}
git tag -a ${version} -m'Elgg ${version}'
git push --tags origin release-${version}

Or create a release on GitHub

Goto releases
Click ‚Draft a new release‘
Enter the version
Select the correct branch (eg 1.12 for a 1.12.x release, 2.3 for a 2.3.x release, etc)
Set the release title as ‚Elgg {version}‘
Paste the CHANGELOG.md part related to this release in the description

Some final administration

Mark GitHub release milestones as completed
Move unresolved tickets in released milestones to later milestones

Update the website ¶

ssh to elgg.org
Clone https://github.com/Elgg/elgg-scripts

Build zip package¶

Use elgg-scripts/build/elgg-starter-project.sh to generate the .zip file. Run without arguments to see usage.

# login as user deploy
sudo -su deploy

# regular release
./elgg-starter-project.sh master 3.0.0 /var/www/www.elgg.org/download/

# MIT release
./elgg-starter-project.sh master 3.0.0-mit /var/www/www.elgg.org/download/

Bemerkung

For Elgg 2.x releases use the 2.x branch of the starter-project (eg. ./elgg-starter-project.sh 2.x 2.0.4 /var/www/www.elgg.org/download/)

Verify that vendor/elgg/elgg/composer.json in the zip file has the expected version.
If not, make sure GitHub has the release tag, and that the starter project has a compatible elgg/elgg item in the composer requires list.

Building 1.x zip packages¶

Use elgg-scripts/build/build.sh to generate the .zip file. Run without arguments to see usage.

# regular release
./build.sh 1.12.5 1.12.5 /var/www/www.elgg.org/download/

# MIT release
./build.sh 1.12.5 1.12.5-mit /var/www/www.elgg.org/download/

Update elgg.org download page¶

Clone https://github.com/Elgg/community
Add the new version to classes/Elgg/Releases.php
Commit and push the changes
Update the plugin on www.elgg.org

composer update elgg/community

Update elgg.org¶

Clone https://github.com/Elgg/www.elgg.org
Change the required Elgg version in composer.json
Update vendors

composer update

Commit and push the changes
Pull to live site

cd /var/www/www.elgg.org && sudo su deploy && git pull

Update dependencies

composer install --no-dev --prefer-dist --optimize-autoloader

Go to community admin panel
- Flush APC cache
- Run upgrade

Make the announcement ¶

This should be the very last thing you do.

Open https://github.com/Elgg/Elgg/blob/<tag>/CHANGELOG.md and copy the contents for that version
Sign in at https://elgg.org/blog and compose a new blog with a summary
Copy in the CHANGELOG contents, clear formatting, and manually remove the SVG anchors
Add tags release and elgg2.x where x is whatever branch is being released
Tweet from the elgg Twitter account

Appendix¶

Miscellaneous information about the project.

Upgrade Notes¶

If you are upgrading your plugins and website to a new major Elgg releases, the following noteworthy changes apply.

See the administrator guides for how to upgrade a live site.

From 3.1 to 3.2¶

Contents

User write access
River items enabled state

User write access ¶

To fix an issue where user owned access collections like Friends or Friend Collections would still show in the access drop down when creating content, even if related plugins are disabled, we needed to change some internal logic. If you want to have an access collection subtype available in the write access you now need to register the subtype with a plugin hook. See the plugin hook reference for ‚access:collections:write:subtypes‘ for more details.

River items enabled state ¶

The enabled state of river items has been deprecated. You should no longer use this property when working with river items.

From 3.0 to 3.1¶

Contents

PHP Version
Plugin screenshots
Loading external files
Setting page owner
Simpletests
Hook and event callbacks
Deprecated Routes
Deprecated CSS libraries
Deprecated JS libraries
Deprecated APIs
Deprecated actions

PHP Version ¶

PHP 7.0 has reached end of life in January 2019. To ensure that Elgg sites are secure, we now require PHP 7.1 for new installations.

If upgrading from a previous Elgg installation make sure you have the correct PHP version installed.

Plugin screenshots ¶

Screenshots added to plugins are no longer supported and will no longer be shown in the plugin details.

Loading external files ¶

The usage of elgg_register_js, elgg_unregister_js and elgg_load_js is discouraged. Make sure your javascript is an AMD module and use elgg_require_js to include it.

The usage of elgg_register_css, elgg_unregister_css and elgg_load_css is discouraged. You can register and include css with the new elgg_require_css function.

Setting page owner ¶

Setting the page owner via the elgg_get_page_owner_guid function parameter is deprecated. Use elgg_set_page_owner_guid.

Simpletests ¶

The core simpletests have been removed from the system. They are all replaced by PHP unit tests or integration tests. The simpletest cli command has been deprecated.

Hook and event callbacks ¶

The legacy style hook and event callback arguments are deprecated. You should switch to the new style as soon as possible.

// old style hook callback
function hook_callback($name, $type, $return_value, $params) {

}

// new style hook callback
function hook_callback(\Elgg\Hook $hook) {
        // now you can use a few new functions
        $params = $hook->getParams();
        $return = $hook->getValue();

        $specific_param = $hook->getParam('specific_param', 'default')
        $entity = $hook->getEntityParam();
        $user = $hook->getUserParam();
}

// old style event callback
function event_callback($name, $type, $object) {

}

// new style event callback
function event_callback(\Elgg\Event $event) {
        // now you can use a few new functions
        $object = $event->getObject();
}

Deprecated Routes ¶

previous:object:thewire This route was not in use. It now has been marked as deprecated.

Deprecated CSS libraries ¶

jquery.imgareaselect Do not use this external css file.

jquery.treeview Do not use this external css file.

Deprecated JS libraries ¶

elgg.avatar_cropper Do not depend on this external javascript library.

jquery.imgareaselect Do not depend on this external javascript library.

jquery.treeview Do not depend on this external javascript library.

Deprecated APIs ¶

access_show_hidden_entities() Use elgg_call() with ELGG_SHOW_DISABLED_ENTITIES flag.

autoregister_views()

count_messages() Use elgg()->system_messages->count().

disable_user_entities()

elgg_enable_entity() Use ElggEntity::enable().

elgg_get_file_list() Use a PHP directory iterator.

elgg_instanceof() Use PHP instanceof type operator.

elgg_is_admin_user() Use ElggUser::isAdmin().

elgg_set_ignore_access() Use elgg_call() with ELGG_IGNORE_ACCESS flag.

elgg_sort_3d_array_by_value()

get_access_list() Use get_access_array().

get_language() Use get_current_language().

get_number_users() Use elgg_count_entities().

pages_register_navigation_tree()

ini_get_bool()

is_not_null()

update_access_collection()

Deprecated actions ¶

admin/delete_admin_notice Replaced by generic entity/delete action.

avatar/crop Handled in avatar/upload action.

avatar/remove Handled in avatar/upload action.

blog/delete Replaced by generic entity/delete action.

messages/delete Replaced by generic entity/delete action.

site_notifications/delete Replaced by generic entity/delete action.

From 2.x to 3.0¶

Contents

PHP 7.0 is now required
$CONFIG is removed!
Removed views
Removed functions/methods
Deprecated APIs
Removed global vars
Removed classes/interfaces
Schema changes
Changes in elgg_get_entities, elgg_get_metadata and elgg_get_annotations getter functions
Boolean entity properties
Metadata Changes
Permissions and Access
Multi Site Changes
Entity Subtable Changes
Friends and Group Access Collection
Subtypes no longer have an ID
Custom class loading
Dependency Injection Container
Search changes
Form and field related changes
Entity and River Menu Changes
Removed libraries
Removed pagehandling
Removed actions
Inheritance changes
Removed JavaScript APIs
Removed hooks/events
Removed forms/actions
APIs that now accept only an $options array
Plugin functions that now require an explicit $plugin_id
Class constructors that now accept only a stdClass object or null
Miscellaneous API changes
View extension behaviour changed
JavaScript hook calling order may change
Widget layout related changes
Routing
Labelling
Request value filtering
Action responses
HtmLawed is no longer a plugin
New approach to page layouts
Likes plugin
Notifications plugin
Pages plugin
Profile plugin
Data Views plugin
Twitter API plugin
Legacy URLs plugin
User validation by email plugin
Email delivery
Theme and styling changes
Comments
Object listing views
Menu changes
Entity icons
Icon glyphs
Autocomplete (user and friends pickers)
Friends collections
Layout of .elgg-body elements
Delete river items
Discussion replies moved to comments
Translations cleanup
System Log
Error logging
Composer asset plugin no longer required
Cron logs
Removed / changed language keys
New MySQL schema features are not applied
Miscellaneous changes
Twitter API plugin
Unit and Integration Testing

PHP 7.0 is now required ¶

5.6 is reaching it’s end of life. PHP 7.0 is now required to install and run Elgg.

`$CONFIG` is removed!¶

Not exactly, however you must audit its usage and should replace it with elgg_get_config() and elgg_set_config(), as recommended since Elgg 1.9.

The global $CONFIG is now a proxy for Elgg’s configuration container, and modifications will fail if you try to alter array properties directly. E.g. $CONFIG->cool_fruit[] = 'Pear';. The silver lining is that failures will emit NOTICEs.

Removed views ¶

forms/account/settings: usersettings extension can now extend the view forms/usersettings/save

forms/admin/site/advanced/system

resources/file/download

output/checkboxes: use output/tags if you want the same behaviour

input/write_access: mod/pages now uses the access:collections:write plugin hook.

invitefriends/form

page/layouts/content: use page/layouts/default

page/layouts/one_column: use page/layouts/default

page/layouts/one_sidebar: use page/layouts/default

page/layouts/two_sidebar: use page/layouts/default

page/layouts/walled_garden: use page/layouts/default

page/layouts/walled_garden/cancel_button

page/layouts/two_column_left_sidebar

page/layouts/widgets/add_panel

page/elements/topbar_wrapper: update your use of page/elements/topbar to include a check for a logged in user

pages/icon

groups/group_sort_menu: use register, filter:menu:groups/all plugin hook

groups/my_status

groups/profile/stats

subscriptions/form/additions: extend notifications/settings/other instead

likes/count: modifications can now be done to the likes_count menu item

likes/css: likes now uses elgg/likes.css

resources/members/index

messageboard/css

notifications/subscriptions/personal

notifications/subscriptions/collections

notifications/subscriptions/form

notifications/subscriptions/jsfuncs

notifications/subscriptions/forminternals

notifications/css

pages/input/parent

river/item: use elgg_view_river_item() to render river items

river/user/default/profileupdate

admin.js

aalborg_theme/homepage.png

aalborg_theme/css

resources/avatar/view: Use entity icon API

ajax_loader.gif

button_background.gif

button_graduation.png

elgg_toolbar_logo.gif

header_shadow.png

powered_by_elgg_badge_drk_bckgnd.gif

powered_by_elgg_badge_light_bckgnd.gif

sidebar_background.gif

spacer.gif

toptoolbar_background.gif

two_sidebar_background.gif

ajax_loader_bw.gif: use graphics/ajax_loader_bw.gif

elgg_logo.png: use graphics/elgg_logo.png

favicon-128.png: use graphics/favicon-128.png

favicon-16.png: use graphics/favicon-16.png

favicon-32.png: use graphics/favicon-32.png

favicon-64.png: use graphics/favicon-64.png

favicon.ico: use graphics/favicon.ico

favicon.svg: use graphics/favicon.svg

friendspicker.png: use graphics/friendspicker.png

walled_garden.jpg: use graphics/walled_garden.jpg

core/friends/collection

core/friends/collections

core/friends/collectiontabs

core/friends/tablelist

core/friends/talbelistcountupdate

lightbox/elgg-colorbox-theme/colorbox-images/*`

navigation/menu/page: now uses navigation/menu/default and a prepare hook

navigation/menu/site: now uses default view

page/elements/by_line: Use object/elements/imprint

forms/admin/site/advanced/security: the site secret information has been moved to forms/admin/security/settings

river/object/file/create: check River

river/object/page/create: check River

river/object/page_top/create: check River

river/relationship/member: check River

object/page_top: use object/page

ajax/discussion/reply/edit: See Discussion replies moved to comments

discussion/replies: See Discussion replies moved to comments

object/discussion_reply: See Discussion replies moved to comments

resources/discussion/reply/edit: See Discussion replies moved to comments

resources/elements/discussion_replies: See Discussion replies moved to comments

river/elements/discussion_replies: See Discussion replies moved to comments

river/object/discussion/create

river/object/discussion_reply/create: See Discussion replies moved to comments

search/object/discussion_reply/entity: See Discussion replies moved to comments

rss/discussion/replies: See Discussion replies moved to comments

search/header

search/layout in both default and rss viewtypes

search/no_results

search/object/comment/entity

search/css: Moved to search/search.css

search/startblurb

bookmarks/bookmarklet.gif

blog_get_page_content_list

blog_get_page_content_archive

blog_get_page_content_edit

forms/invitefriends/invite: use forms/friends/invite

resources/invitefriends/invite: use resources/friends/invite

resources/reportedcontent/add

resources/reportedcontent/add_form

resources/site_notifications/view: Use resources/site_notifications/owner

resources/site_notifications/everyone: Use resources/site_notifications/all

Removed functions/methods ¶

All the functions in engine/lib/deprecated-1.9.php were removed. See https://github.com/Elgg/Elgg/blob/2.0/engine/lib/deprecated-1.9.php for these functions. Each @deprecated declaration includes instructions on what to use instead. All the functions in engine/lib/deprecated-1.10.php were removed. See https://github.com/Elgg/Elgg/blob/2.0/engine/lib/deprecated-1.10.php for these functions. Each @deprecated declaration includes instructions on what to use instead.

elgg_register_library: require your library files so they are available globally to other plugins

elgg_load_library

activity_profile_menu

can_write_to_container: Use ElggEntity->canWriteToContainer()

create_metadata_from_array

metadata_array_to_values

datalist_get

datalist_set

detect_extender_valuetype

developers_setup_menu

elgg_disable_metadata

elgg_enable_metadata

elgg_get_class_loader

elgg_get_metastring_id

elgg_get_metastring_map

elgg_register_class

elgg_register_classes

elgg_register_viewtype

elgg_is_registered_viewtype

file_delete: Use ElggFile->deleteIcon()

file_get_type_cloud

file_type_cloud_get_url

get_default_filestore

get_site_entity_as_row

get_group_entity_as_row

get_missing_language_keys

get_object_entity_as_row

get_user_entity_as_row

update_river_access_by_object

garbagecollector_orphaned_metastrings

groups_access_collection_override

groups_get_group_tool_options: Use elgg()->group_tools->all()

groups_join_group: Use ElggGroup::join

groups_prepare_profile_buttons: Use register, menu:title hook

groups_register_profile_buttons: Use register, menu:title hook

groups_setup_sidebar_menus

groups_set_icon_url

groups_setup_sidebar_menus

messages_notification_msg

set_default_filestore

generate_user_password: Use ElggUser::setPassword

row_to_elggrelationship

run_function_once: Use Elgg\Upgrade\Batch interface

system_messages

notifications_plugin_pagesetup

elgg_format_url: Use elgg_format_element() or the „output/text“ view for HTML escaping.

get_site_by_url

elgg_override_permissions: No longer used as handler for permissions_check and container_permissions_check hooks

elgg_check_access_overrides

AttributeLoader became obsolete and was removed

Application::loadSettings

ElggEntity::addToSite

ElggEntity::disableMetadata

ElggEntity::enableMetadata

ElggEntity::getSites

ElggEntity::removeFromSite

ElggEntity::isFullyLoaded

ElggEntity::clearAllFiles

ElggPlugin::getFriendlyName: Use ElggPlugin::getDisplayName()

ElggPlugin::setID

ElggPlugin::unsetAllUsersSettings

ElggFile::setFilestore: ElggFile objects can no longer use custom filestores.

ElggFile::size: Use getSize

ElggDiskFilestore::makeFileMatrix: Use Elgg\EntityDirLocator

ElggData::get: Usually can be replaced by property read

ElggData::getClassName: Use get_class()

ElggData::set: Usually can be replaced by property write

ElggEntity::setURL: See getURL for details on the plugin hook

ElggMenuBuilder::compareByWeight: Use compareByPriority

ElggMenuItem::getWeight: Use getPriority

ElggMenuItem::getContent: Use elgg_view_menu_item()

ElggMenuItem::setWeight: Use setPriority

ElggRiverItem::getPostedTime: Use getTimePosted

ElggSession has removed all deprecated methods

ElggSite::addEntity

ElggSite::addObject

ElggSite::addUser

ElggSite::getEntities: Use elgg_get_entities()

ElggSite::getExportableValues: Use toObject

ElggSite::getMembers: Use elgg_get_entities()

ElggSite::getObjects: Use elgg_get_entities()

ElggSite::listMembers: Use elgg_list_entities()

ElggSite::removeEntity

ElggSite::removeObject

ElggSite::removeUser

ElggSite::isPublicPage: Logic moved to the router and should not be accessed directly

ElggSite::checkWalledGarden: Logic moved to the router and should not be accessed directly

ElggUser::countObjects: Use elgg_get_entities()

Logger::getClassName: Use get_class()

Elgg\Application\Database::getTablePrefix: Read the prefix property

elgg_view_access_collections()

ElggSession::get_ignore_access: Use getIgnoreAccess

ElggSession::set_ignore_access: Use setIgnoreAccess

profile_pagesetup

pages_can_delete_page: Use $entity->canDelete()

pages_search_pages

pages_is_page: use $entity instanceof ElggPage

discussion_comment_override: See Discussion replies moved to comments

discussion_can_edit_reply: See Discussion replies moved to comments

discussion_reply_menu_setup: See Discussion replies moved to comments

discussion_reply_container_logic_override: See Discussion replies moved to comments

discussion_reply_container_permissions_override: See Discussion replies moved to comments

discussion_update_reply_access_ids: See Discussion replies moved to comments

discussion_search_discussion: See Discussion replies moved to comments

discussion_add_to_river_menu: See Discussion replies moved to comments

discussion_prepare_reply_notification: See Discussion replies moved to comments

discussion_redirect_to_reply: See Discussion replies moved to comments

discussion_ecml_views_hook: See Discussion replies moved to comments

search_get_where_sql

search_get_ft_min_max

search_get_order_by_sql

search_consolidate_substrings

search_remove_ignored_words

search_get_highlighted_relevant_substrings

search_highlight_words

search_get_search_view

search_custom_types_tags_hook

search_tags_hook

search_users_hook

search_groups_hook

search_objects_hook

members_list_popular

members_list_newest

members_list_online

members_list_alpha

members_nav_popular

members_nav_newest

members_nav_online

members_nav_alpha

uservalidationbyemail_generate_code

All functions around entity subtypes table:

add_subtype: Use elgg_set_entity_class at runtime
update_subtype: Use elgg_set_entity_class at runtime
remove_subtype
get_subtype_id
get_subtype_from_id
get_subtype_class: Use elgg_get_entity_class
get_subtype_class_from_id

All caches have been consolidated into a single API layer. The following functions and methods have been removed:

is_memcache_available
_elgg_get_memcache
_elgg_invalidate_memcache_for_entity
ElggMemcache
ElggFileCache
ElggStaticVariableCache
ElggSharedMemoryCache
Elgg\Cache\Pool interface and all extending classes

As a result of system log changes:

system_log_default_logger: moved to system_log plugin
system_log_listener: moved to system_log plugin
system_log: moved to system_log plugin
get_system_log: renamed to system_log_get_log and moved to system_log plugin
get_log_entry: renamed to system_log_get_log_entry and moved to system_log plugin
get_object_from_log_entry: renamed to system_log_get_object_from_log_entry and moved to system_log plugin
archive_log: renamed to system_log_archive_log and moved to system_log plugin
logbrowser_user_hover_menu: renamed to system_log_user_hover_menu and moved to system_log plugin
logrotate_archive_cron: renamed to system_log_archive_cron and moved to system_log plugin
logrotate_delete_cron: renamed to system_log_delete_cron and moved to system_log plugin
logrotate_get_seconds_in_period: renamed to system_log_get_seconds_in_period and moved to system_log plugin
log_browser_delete_log: renamed to system_log_browser_delete_log and moved to system_log plugin

Deprecated APIs ¶

ban_user: Use ElggUser->ban()

create_metadata: Use ElggEntity setter or ElggEntity->setMetadata()

update_metadata: Use ElggMetadata->save()

get_metadata_url

create_annotation: Use ElggEntity->annotate()

update_metadata: Use ElggAnnotation->save()

elgg_get_user_validation_status: Use ElggUser->isValidated()

make_user_admin: Use ElggUser->makeAdmin()

remove_user_admin: Use ElggUser->removeAdmin()

unban_user: Use ElggUser->unban()

elgg_get_entities_from_attributes: Use elgg_get_entities()

elgg_get_entities_from_metadata: Use elgg_get_entities()

elgg_get_entities_from_relationship: Use elgg_get_entities()

elgg_get_entities_from_private_settings: Use elgg_get_entities()

elgg_get_entities_from_access_id: Use elgg_get_entities()

elgg_list_entities_from_metadata: Use elgg_list_entities()

elgg_list_entities_from_relationship: Use elgg_list_entities()

elgg_list_entities_from_private_settings: Use elgg_list_entities()

elgg_list_entities_from_access_id: Use elgg_list_entities()

elgg_list_registered_entities: Use elgg_list_entities()

elgg_batch_delete_callback

\Elgg\Project\Paths::sanitize: Use \Elgg\Project\Paths::sanitize()

elgg_group_gatekeeper: Use elgg_entity_gatekeeper()

get_entity_dates: Use elgg_get_entity_dates()

messages_set_url: Use ElggEntity::getURL()

Removed global vars ¶

$CURRENT_SYSTEM_VIEWTYPE

$DEFAULT_FILE_STORE

$ENTITY_CACHE

$SESSION: Use the API provided by elgg_get_session()

$CONFIG->site_id: Use 1

$CONFIG->search_info

$CONFIG->input: Use set_input and get_input

Removed classes/interfaces ¶

FilePluginFile: replace with ElggFile (or load with get_entity())

Elgg_Notifications_Notification

Elgg\Database\EntityTable\UserFetchResultException.php

Elgg\Database\MetastringsTable

Elgg\Database\SubtypeTable

Exportable and its methods export and getExportableValues: Use toObject

ExportException

Importable and its method import.

ImportException

ODD and all classes beginning with ODD*.

XmlElement

Elgg_Notifications_Event: Use \Elgg\Notifications\Event

Elgg\Mail\Address: use Elgg\Email\Address

ElggDiscussionReply: user ElggComment see Discussion replies moved to comments

Schema changes ¶

The storage engine for the database tables has been changed from MyISAM to InnoDB. You maybe need to optimize your database settings for this change. The datalists table has been removed. All settings from datalists table have been merged into the config table.

Metastrings in the database have been denormalized for performance purposes. We removed the metastrings table and put all the string values directly in the metadata and annotation tables. You need to update your custom queries to reflect these changes. Also the msv and msn table aliases are no longer available. It is best practice not to rely on the table aliases used in core queries. If you need to use custom clauses you should do your own joins.

From the „users_entity“ table, the password and hash columns have been removed.

The geocode_cache table has been removed as it was no longer used.

subtype column in entities table no longer holds a subtype ID, but a subtype string entity_subtypes table has been dropped.

type, subtype and access_id columns in river table have been dropped. For queries without elgg_get_river() join the entities table on object_guid to check the type and the subtype of the entity. Access column hasn’t been in use for some time: queries are built to ensure access to all three entities (subject, object and target).

Changes in `elgg_get_entities`, `elgg_get_metadata` and `elgg_get_annotations` getter functions ¶

elgg_get_entities now accepts all options that were previously distributed between elgg_get_entities_from_metadata, elgg_get_entities_from_annotations, elgg_get_entities_from_relationship, elgg_get_entities_from_private_settings and elgg_get_entities_from_access_id. The latter have been been deprecated.

Passing raw MySQL statements to options is deprecated. Plugins are advised to use closures that receive an instance of \Elgg\Database\QueryBuilder and prepare the statement using database abstraction layer. On one hand this will ensure that all statements are properly sanitized using the database driver, on the other hand it will allow us to transition to testable object-oriented query building.

wheres statements should not use raw SQL strings, instead pass an instance of \Elgg\Database\Clauses\WhereClause or a closure that returns an instance of \Doctrine\DBAL\Query\Expression\CompositeExpression:

elgg_get_entities([
   'wheres' => [
        function(\Elgg\Database\QueryBuilder $qb, $alias) {
           $joined_alias = $qb->joinMetadataTable($alias, 'guid', 'status');
           return $qb->compare("$joined_alias.name", 'in', ['draft', 'unsaved_draft'], ELGG_VALUE_STRING);
        }
   ]
]);

joins, order_by, group_by, selects clauses should not use raw SQL strings. Use closures that receive an instance of \Elgg\Database\QueryBuilder and return a prepared statement.

The reverse_order_by option has been removed.

Plugins should not rely on joined and selected table aliases. Closures passed to the options array will receive a second argument that corresponds to the selected table alias. Plugins must perform their own joins and use joined aliases accordingly.

Note that all of the private API around building raw SQL strings has also been removed. If you were relying on them in your plugins, be advised that anything marked as @access private or @internal in core can be modified and removed at any time, and we do not guarantee any backward compatibility for those functions. DO NOT USE THEM. If you find yourself needing to use them, open an issue on Github and we will consider adding a public equivalent.

Boolean entity properties ¶

Storage of metadata, annotation and private setting values has been aligned.

Boolean values are cast to integers when saved: false is stored as 0 and true is stored as 1. This has breaking implications for private settings, which were previously stored as empty strings for false values. Plugins should write their own migration scripts to alter DB values from empty strings to 0 (for private settings that are expected to store boolean values) to ensure that elgg_get_entities() can retrieve these values with private_setting_name_value_pairs containing false values. This applies to plugin settings, as well as any private settings added to entities.

Metadata Changes ¶

Metadata is no longer access controlled. If your plugin created metadata with restricted access, those restrictions will not be honored. You should use annotations or entities instead, which do provide access control.

Do not read or write to the access_id property on ElggMetadata objects.

Metadata is no longer enabled or disabled. You can no longer perform the enable and disable API calls on metadata.

Metadata no longer has an owner_guid. It is no longer possible to query metadata based on owner_guids. Subsequently, ElggMetadata::canEdit() will always return true regardless of the logged in user, unless explicitly overriden by a plugin hook.

Permissions and Access ¶

User capabilities service will no longer trigger permission check hooks when:

permissions are checked for an admin user

permissions are checked when access is ignored with elgg_set_ignore_access()

This means that plugins can no longer alter permissions in aforementioned cases.

elgg_check_access_overrides() has been removed, as plugins will no longer need to validate access overrides.

The translations for the default Elgg access levels have new translation language keys.

Multi Site Changes ¶

Pre 3.0 Elgg has some (partial) support for having multiple sites in the same database. This Multi Site concept has been completely removed in 3.0. Entities no longer have the site_guid attribute. This means there is no longer the ability to have entities on different sites. If you currently have multiple sites in your database, upgrading Elgg to 3.0 will fail. You need to separate the different sites into separate databases/tables.

Related to the removal of the Multi Site concept in Elgg, there is no longer a need for entities having a ‚member_of_site‘ relationship with the Site Entity. All functions related to adding/removing this relationship has been removed. All existing relationships will be removed as part of this upgrade.

Setting ElggSite::$url has no effect. Reading the site URL always pulls from the $CONFIG->wwwroot set in settings.php, or computed by Symphony Request.

ElggSite::save() will fail if it isn’t the main site.

Entity Subtable Changes ¶

The subtable sites_entity for ElggSite no longer exists. All attributes have been moved to metadata. The subtable groups_entity for ElggGroup no longer exists. All attributes have been moved to metadata. The subtable objects_entity for ElggObject no longer exists. All attributes have been moved to metadata. The subtable users_entity for ElggUser no longer exists. All attributes have been moved to metadata.

If you have custom queries referencing this table you need to update them. If you have function that rely on Entity->getOriginalAttributes() be advised that this will only return the base attributes of an ElggEntity and no longer contain the secondary attributes.

Friends and Group Access Collection ¶

The access collections table now has a subtype column. This extra data helps identifying the purpose of the ACL. The user owned access collections are assumed to be used as Friends Collections and now have the ‚friends_collection‘ subtype. The groups access collection information was previously stored in the group_acl metadata. With the introduction of the ACL subtype this information has been moved to the ACL subtype attribute.

The ACCESS_FRIENDS access_id has been migrated to an actual access collection (with the subtype friends). All entities and annotations have been updated to use the new access collection id. The access collection is created when a user is created. When a relationship of the type friends is created, the related guid will also be added to the access collection. You can no longer save or update entities with the access id ACCESS_FRIENDS.

Subtypes no longer have an ID ¶

Entity subtypes have been denormalized. entity_subtypes table has been removed and subtype column in entities table simply holds the string representation of the subtype.

Consequently, all API around adding/updating entity subtypes and classes have been removed.

Plugins can now use elgg_set_entity_class() and elgg_get_entity_class() to register a custom entity class at runtime (e.g. in system init handler).

All entities now MUST have a subtype. By default, the following subtypes are added and reserved:

user for users

group for groups

site for sites

Custom class loading ¶

Elgg no longer provides API functions to register custom classes. If you need custom classes you can use PSR-0 classes in the /classes folder of your plugin or use composer for autoloading of additional classes.

The following class registration related functions have been removed:

elgg_get_class_loader

elgg_register_class

elgg_register_classes

Dependency Injection Container ¶

Plugins can now define their services and attach them to Elgg’s public DI container by providing definitions in elgg-services.php in the root of the plugin directory.

elgg() no longer returns an instance of Elgg application, but a DI container instance.

Search changes ¶

We have added a search service into core, consequently the search plugin now only provides a user interface for displaying forms and listing search results. Many of the views in the search plugin have been affected by this change.

The FULLTEXT indices have been removed on various tables. The search plugin will now always use a like query when performing a search.

See Search Service and Search hooks documentation for detailed information about new search capabilities.

Removed libraries ¶

elgg_register_library and elgg_load_library have been removed. These functions had little impact on performance (especially with OPCache enabled), and made it difficult for other plugins to work with APIs contained in libraries. Additionally it was difficult for developers to know that APIs were contained in a library while there being autocompleted by IDE.

If you are concerned with performance, move the logic to classes and let PHP autoload them as necessary, otherwise use require_once and require your libraries.

Removed pagehandling ¶

file/download

file/search

groupicon

twitterservice

collections/pickercallback

discussion/reply: See Discussion replies moved to comments

expages

invitefriends: Use friends/{username}/invite

messages/compose: Use messages/add

reportedcontent

Removed actions ¶

file/download: Use elgg_get_inline_url or elgg_get_download_url

file/delete: Use entity/delete action

import/opendd

discussion/reply/save: See Discussion replies moved to comments

discussion/reply/delete: See Discussion replies moved to comments

comment/delete: Use entity/delete action

uservalidationbyemail/bulk_action: use admin/user/bulk/validate or admin/user/bulk/delete

uservalidationbyemail/delete: use admin/user/bulk/delete

uservalidationbyemail/validate: use admin/user/bulk/validate

invitefriends/invite: use friends/invite

Inheritance changes ¶

ElggData (and hence most Elgg domain objects) no longer implements Exportable

ElggEntity no longer implements Importable

ElggGroup no longer implements Friendable

ElggRelationship no longer implements Importable

ElggSession no longer implements ArrayAccess

Elgg\Application\Database no longer extends Elgg\Database

Removed JavaScript APIs ¶

admin.js

elgg.widgets: Use the elgg/widgets module. The „widgets“ layouts do this module automatically

lightbox.js: Use the elgg/lightbox module as needed

lightbox/settings.js: Use the getOptions, ui.lightbox JS hook or the data-colorbox-opts attribute

elgg.ui.popupClose: Use the elgg/popup module

elgg.ui.popupOpen: Use the elgg/popup module

elgg.ui.initAccessInputs

elgg.ui.river

elgg.ui.initDatePicker: Use the input/date module

elgg.ui.likesPopupHandler

elgg.embed: Use the elgg/embed module

elgg.discussion: Use the elgg/discussion module

embed/custom_insert_js: Use the embed, editor JS hook

elgg/ckeditor.js: replaced by elgg-ckeditor.js

elgg/ckeditor/set-basepath.js

elgg/ckeditor/insert.js

jQuery.cookie: Use elgg.session.cookie

jquery.jeditable

likes.js: The elgg/likes module is loaded automatically

messageboard.js

elgg.autocomplete is no longer defined.

elgg.messageboard is no longer defined.

jQuery.fn.friendsPicker

elgg.ui.toggleMenu is no longer defined

elgg.ui.toggleMenuItems: Use data-toggle attribute when registering toggleable menu items

uservalidationbyemail/js.php: Use the elgg/uservalidationbyemail module

discussion.js: See Discussion replies moved to comments

Removed hooks/events ¶

Event login, user: Use login:before or login:after. Note the user is not logged in during the login:before event

Event delete, annotations: Use delete, annotation

Event pagesetup, system: Use the menu or page shell hooks instead

Event upgrade, upgrade: Use upgrade, system instead

Hook index, system: Override the resources/index view

Hook object:notifications, <type>: Use the hook send:before, notifications

Hook output:before, layout: Use view_vars, page/layout/<layout_name>

Hook output:after, layout: Use view, page/layout/<layout_name>

Hook email, system: Use more granular <hook>, system:email hooks

Hook email:message, system: Use zend:message, system:email hook

Hook members:list, <page>: Use your own pagehandler or route hook

Hook members:config, <page>: Use register, menu:filter:members

Hook profile_buttons, group: Use register, menu:title

Removed forms/actions ¶

notificationsettings/save form and action

notificationsettings/groupsave form and action

discussion/reply/save form and action

APIs that now accept only an `$options` array ¶

ElggEntity::getAnnotations

ElggEntity::getEntitiesFromRelationship

ElggGroup::getMembers

ElggUser::getGroups

ElggUser::getFriends (as part of Friendable)

ElggUser::getFriendsOf (as part of Friendable)

ElggUser::getFriendsObjects (as part of Friendable)

ElggUser::getObjects (as part of Friendable)

find_active_users

elgg_get_admin_notices

Plugin functions that now require an explicit `$plugin_id`¶

elgg_get_all_plugin_user_settings

elgg_set_plugin_user_setting

elgg_unset_plugin_user_setting

elgg_get_plugin_user_setting

elgg_set_plugin_setting

elgg_get_plugin_setting

elgg_unset_plugin_setting

elgg_unset_all_plugin_settings

Class constructors that now accept only a `stdClass` object or `null`¶

ElggAnnotation: No longer accepts an annotation ID

ElggGroup: No longer accepts a GUID

ElggMetadata: No longer accepts a metadata ID

ElggObject: No longer accepts a GUID

ElggRelationship: No longer accepts a relationship ID or null

ElggSite: No longer accepts a GUID or URL

ElggUser: No longer accepts a GUID or username

ElggPlugin: No longer accepts a GUID or path. Use ElggPlugin::fromId to construct a plugin from its path

Miscellaneous API changes ¶

ElggBatch: You may only access public properties

ElggEntity: The tables_split and tables_loaded properties were removed

ElggEntity: Empty URLs will no longer be normalized. This means entities without URLs will no longer result in the site URL

ElggGroup::removeObjectFromGroup requires passing in an ElggObject (no longer accepts a GUID)

ElggUser::$salt no longer exists as an attribute, nor is it used for authentication

ElggUser::$password no longer exists as an attribute, nor is it used for authentication

elgg_get_widget_types no longer supports $exact as the 2nd argument

elgg_instanceof no longer supports the fourth class argument

elgg_view: The 3rd and 4th (unused) arguments have been removed. If you use the $viewtype argument, you must update your usage.

elgg_view_icon no longer supports true as the 2nd argument

elgg_list_entities no longer supports the option view_type_toggle

elgg_list_registered_entities no longer supports the option view_type_toggle

elgg_log no longer accepts the level "DEBUG"

elgg_dump no longer accepts a $to_screen argument.

elgg_gatekeeper and elgg_admin_gatekeeper no longer report login or admin as forward reason, but 403

Application::getDb() no longer returns an instance of Elgg\Database, but rather a Elgg\Application\Database

$CONFIG is no longer available as a local variable inside plugin start.php files.

elgg_get_config('siteemail') is no longer available. Use elgg_get_site_entity()->email.

ElggEntity::saveIconFromUploadedFile only saves master size, the other sizes are created when requested by ElggEntity::getIcon() based on the master size

ElggEntity::saveIconFromLocalFile only saves master size, the other sizes are created when requested by ElggEntity::getIcon() based on the master size

ElggEntity::saveIconFromElggFile only saves master size, the other sizes are created when requested by ElggEntity::getIcon() based on the master size

Group entities do no longer have the magic username attribute.

Pagehandling will no longer detect group:<guid> in the URL

The CRON interval reboot is removed.

The URL endpoints js/ and css/ are no longer supported. Use elgg_get_simplecache_url().

The generic comment save action no longer sends the notification directly, this has been offloaded to the notification system.

The script engine/start.php is removed.

The functions set_config, unset_config and get_config have been deprecated and replaced by elgg_set_config, elgg_remove_config and elgg_get_config.

Config values path, wwwroot, and dataroot are not read from the database. The settings.php file values are always used.

Config functions like elgg_get_config no longer trim keys.

If you override the view navigation/menu/user_hover/placeholder, you must change the config key lazy_hover:menus to elgg_lazy_hover_menus.

The config value entity_types is no longer present or used.

Uploaded images are autorotated based on their orientation metadata.

The view object/widget/edit/num_display now uses an input/number field instead of input/select; you might need to update your widget edit views accordingly.

Annotation names are no longer trimmed during save

View extension behaviour changed ¶

An extended view now will receive all the regular hooks (like the view_vars hook). It now is also possible to extend view extensions. With this change in behaviour all view rendering will behave the same. It no longer matters if it was used as an extension or not.

JavaScript hook calling order may change ¶

When registering for hooks, the all keyword for wildcard matching no longer has any effect on the order that handlers are called. To ensure your handler is called last, you must give it the highest priority of all matching handlers, or to ensure your handler is called first, you must give it the lowest priority of all matching handlers.

If handlers were registered with the same priority, these are called in the order they were registered.

To emulate prior behavior, Elgg core handlers registered with the all keyword have been raised in priority. Some of these handlers will most likely be called in a different order.

Routing ¶

Page handling using elgg_register_page_handler() has been deprecated.

We have added new routing API using elgg_register_route(), which allows plugins to define named routes, subsequently using route names to generate URLs using elgg_generate_url().

See routing docs for details.

As a result of this change all core page handlers have been removed, and any logic contained within these page handlers has been moved to respective resource views.

elgg_generate_entity_url() has been added as shortcut way to generate URLs from named routes that depend on entity type and subtype.

Use of handler parameter in entity menus has been deprecated in favour of named entity routes.

Gatekeeper function have been refactored to serve as middleware in the routing process, and as such they no longer return values. These functions throw HTTP exceptions that are then routed to error pages and can be redirected to other pages via hooks.

Labelling ¶

Entity and collection labelling conventions have changed to comply with the new routing patterns:

return [
   'item:object:blog' => 'Blog',
   'collection:object:blog' => 'Blogs',
   'collection:object:blog:all' => 'All site blogs',
   'collection:object:blog:owner' => '%s\'s blogs',
   'collection:object:blog:group' => 'Group blogs',
   'collection:object:blog:friends' => 'Friends\' blogs',
   'add:object:blog' => 'Add blog post',
   'edit:object:blog' => 'Edit blog post',
];

These conventions are used across the routing and navigation systems, so plugins are advised to follow them.

Request value filtering ¶

set_input() and get_input() no longer trim values.

Action responses ¶

All core and core plugin actions now all use the new Http Response functions like elgg_ok_response and elgg_error_response instead of forward(). The effect of this change is that is most cases the ‚forward‘, ‚system‘ hook is no longer triggered. If you like to influence the responses you now can use the ‚response‘, ‚action:<name/of/action>‘ hook. This gives you more control over the response and allows to target a specific action very easily.

HtmLawed is no longer a plugin ¶

Do not call elgg_load_library('htmlawed').

In the hook params for 'config', 'htmlawed', the hook_tag function name changed.

New approach to page layouts ¶

one_column, one_sidebar, two_sidebar and content layouts have been removed - instead layout rendering has been centralized in the default. Updated default layout provides full control over the layout elements via $vars. For maximum backwards compatibility, calls to elgg_view_layout() with these layout names will still yield expected output, but the plugins should start using the default layout with an updated set of parameters.

Page layouts have been decomposed into smaller elements, which should make it easier for themes to target specific layout elements without having to override layouts at large.

As a result of these changes:

all layouts are consistent in how they handle title and filter menus, breadcrumbs and layout subviews

all layouts can now be easily extended to have multiple tabs. Plugins can pass filter_id parameter that will allow other plugins to hook into register, menu:filter:<filter_id> hook and add new tabs. If no filter_id is provided, default register, menu:filter hook can be used.

layout views and subviews now receive identifier and segments of the page being rendered

layout parameters are available to title and filter menu hooks, which allows resources to provide additional context information, for example, an $entity in case of a profile resource

Plugins and themes should:

Update calls to elgg_view_layout() to use default layout

Update replace nav parameter in layout views with breadcrumbs parameter

Update their use of filter parameter in layout views by either providing a default set of filter tabs, or setting a filter_id parameter and using hooks

Remove page/layouts/one_column view

Remove page/layouts/one_sidebar view

Remove page/layouts/two_sidebar view

Remove page/layouts/content view

Update their use of page/layouts/default

Update their use of page/layouts/error

Update their use of page/layouts/elements/filter

Update their use of page/layouts/elements/header

Update their use of page/layouts/elements/footer

Update their use of page/elements/title

Update their use of navigation/breadcrumbs to pass $vars['breadcrumbs'] to elgg_get_breadcrumbs()

Update hook registrations for output:before, layout to view_vars, page/layout/<layout_name>

Update hook registrations for output:after, layout to view, page/layout/<layout_name>

Likes plugin ¶

Likes no longer uses Elgg’s toggle API, so only a single likes menu item is used. The add/remove actions no longer return Ajax values directly, as likes status data is now returned with every Ajax request that sends a „guid“. When the number of likes is zero, the likes_count menu item is now hidden by adding .hidden to the LI element, instead of the anchor. Also the likes_count menu item is a regular link, and is no longer created by the likes/count view.

Notifications plugin ¶

Notifications plugin has been rewritten dropping many views and actions. The purpose of this rewrite was to implement a more efficient, extendable and scalable interface for managing notifications preferences. We have implemented a much simpler markup and removed excessive styling and javascript that was required to make the old interface work.

If your plugin is extending any of the views or relies on any actions in the notifications plugin, it has to be updated.

Pages plugin ¶

The suptype page_top has been migrated into the subtype page. The subtype page has it’s own class namely ElggPage. In order to check if an ElggPage is a top page the class function ElggPage->isTopPage() was added.

All pages have a metadata value for parent_guid, for top pages this contains 0.

Profile plugin ¶

All profile related functionality has been moved out of core into this plugin. Most noteable are the profile field admin utility and the hook to set up the profile fields config data.

Data Views plugin ¶

The Data Views plugin no longer comes bundled.

Twitter API plugin ¶

The twitter_api plugin has been removed from the Elgg core. The plugin is still available as the Composer package elgg/twitter_api, in order to install it add the following to you composer.json require section:

{
        "require": {
                "elgg/twitter_api": "~1.9"
        }
}

Legacy URLs plugin ¶

The legacy_urls plugin has been removed from the Elgg core. The plugin is still available as the Composer package elgg/legacy_urls, in order to install it add the following to you composer.json require section:

{
        "require": {
                "elgg/legacy_urls": "~2.3"
        }
}

User validation by email plugin ¶

The listing view of unvalidated users has been moved from the plugin to Elgg core. Some generic action (eg. validate and delete) have also been moved to Elgg core.

Email delivery ¶

To provide for more granularity in email handling and delivery, email, system hook has been removed. New email service provides for several other replacement hooks that allow plugins to control email content, format, and transport used for delivery.

elgg_set_email_transport() can now be used to replace the default Sendmail transport with another instance of \Zend\Mail\Transport\TransportInterface, e.g. SMTP, in-memory, or file transport. Note that this function must be called early in the boot process. Note that if you call this function on each request, using plugin settings to determine transport config may not be very efficient - store these settings in as datalist or site config values, so they are loaded from boot cache.

Theme and styling changes ¶

Aalborg theme is no longer bundled with Elgg. Default core theme is now based on Aalboard, but it has undergone major changes.

Notable changes in plugins:

Topbar, navbar and header have been combined into a single responsive topbar component

Default inner width is now 1280px (80rem * 16px/1rem)

Preferred unit of measurement is now rem and not px

The theme uses 8-point grid system <https://builttoadapt.io/intro-to-the-8-point-grid-system-d2573cde8632>

Menus, layout elements and other components now use flexbox

Reset is done using 8-point grid system <https://necolas.github.io/normalize.css/>

Media queries have been rewritten for mobile-first experience

Form elements (text inputs, buttons and selects) now have an equal height of 2.5rem

Layout header is now positioned outside of the layout columns, which have been wrapped into elgg-layout-columns

z-index properties have been reviewed and stacked with simple iteration instead of 9999999 <https://hackernoon.com/my-approach-to-using-z-index-eca67feb079c>.

Color scheme has been changed to highlight actionable elements and reduce abundance of gray shades

search plugin no longer extends page/elements/header and instead page/elements/topbar renders search/search_box view

.elgg-icon no longer has a global font-size, line-height or color: these values will be inherited from parent items

Support for .elgg-icon-hover has been dropped

User „hover“ icons are no longer covered with a „caret“ icon

Comments ¶

Submitting comments is now AJAXed. After a succesful submission the comment list will be updated automatically.

The following changes have been made to the comment notifications.

The language keys related to comment notifications have changed. Check the generic_comment:notification:owner: language keys

The action for creating a comment (action/comment/save) was changed. If your plugin overruled this action you should have a look at it in order to prevent double notifications

Object listing views ¶

object/elements/full/body now wraps the full listing body in a .elgg-listing-full-body wrapper

object/elements/full now supports attachments and responses which are rendered after listing body

In core plugins, resource views no longer render comments/replies - instead they pass a show_responses flag to the entity view, which renders the responses and passes them to the full listing view. Third party plugins will need to update their uses of object/<subtype> and resources/<handler>/view views.

Full discussion view is now rendered using object/elements/full view

object/file now passes image (specialcontent) view as an attachment to the full listing view

Menu changes ¶

Default sorting of menu items has been changed from text to priority.

Note that register and prepare hooks now use collections API. For the most part, all hooks should continue working, as long as they are not performing complex operations with arrays.

Support for icon and badge parameters was added. Plugins should start using these parameters and prefer them to a single text parameter. CSS should be used to control visibility of the label, icon and badge, instead of conditionals in preparing menu items.

All menus are now wrapped with nav.elgg-menu-container to ensure that multiple menu sections have a single parent element, and can be styled using flexbox or floats.

All menu items are now identified with with data-menu-item attribute, sections - with data-menu-section, containers with - data-menu-name attributes.

topbar menu:

account menu item with priority 800 added to alt section

site_notifications menu item is now a child of account with priority 100

usersettings menu item is now a child of account with priority 300

administration menu item is now a child of account with priority 800

logout menu item is now a child of account with priority 900

dashboard menu item now is now a child of acount has priority of 100

In default section (profile, friends, messages), core menu items now use icon parameter and use CSS to hide the label. Plugins that register items to this section and expect a visible label need to update their CSS.

profile menu item is now a child of account

friends menu item is now a child of account

entity menu:

access menu item has been removed. Access information is now rendered in the entity byline.

user_hover menu:

All items use the icon parameter.

The layout of the dropdown has been changed. If you have modified the look and feel of this dropdown, you might need to update your HTML/CSS.

widget menu:

collapse menu item has been removed and CSS updated accordingly

title menu:

The profile plugin no longer uses the actions section of the user_hover menu, but registers regulare title menu items.

extras menu:

This menu has been removed from the page layout. Menu items that registered for this menu have been moved to other menus.

groups:my_status menu:

This menu has been removed from the group profile page.

site_notifications menu:

This menu has been removed. Site Notification objects now use the entity menu for actions.

site menu:

Registration of custom menu item defined in admin interface has been moved to register, menu:site hook. navigation/menu/site view has been removed. Site menu now adds a more` menu item directly to the ``default section.

Entity icons ¶

Default icon image files have been moved and re-mapped as follows:

Default icons: views/default/icon/default/$size.png

User icons: views/default/icon/user/default/$size.gif

Group icons: views/default/icon/group/default/$size.gif in the groups plugin

Groups icon files have been moved from groups/<guid><size>.jpg relative to group owner’s directory on filestore to a location prescribed by the entity icon service. Plugins should stop accessing files on the filestore directly and use the entity icon API. Upgrade script is available via admin interface.

The generation of entity icons has ben changed. No longer will all the configured sizes be generated when calling one of the entity icon functions (ElggEntity::saveIconFromUploadedFile, ElggEntity::saveIconFromLocalFile or ElggEntity::saveIconFromElggFile), but only the master size. The other configured sizes will be generated when requesting that size based of the master icon.

Icon glyphs ¶

FontAwesome has been upgraded to version 5.0+. There were certain changes to how FontAwesome glyphs are rendered. The core will take care of most changes (e.g. mapping old icon names to new ones, and using the correct prefix for brand and solid icons).

Autocomplete (user and friends pickers)¶

Friends Picker input is now rendered using input/userpicker.

Plugins should:

Update overriden input/userpicker to support new only_friends parameter

Remove friends picker CSS from their stylesheets

Friends collections ¶

Friends collections UI has been moved to its own plugins - friends_collections.

Layout of `.elgg-body` elements ¶

In 3.0, these elements by default no longer stretch to fill available space in a block context. They still clear floats and allow breaking words to wrap text.

Core modules and layouts that relied on space-filling have been reworked for Flexbox and we encourage devs to do the same, rather than use the problematic overflow: hidden.

Delete river items ¶

The function elgg_delete_river() which was deprecated in 2.3, has been reinstated. Notable changes between the internals of this function are;

It accepts all $options from elgg_get_river() but requires at least one of the following params to be set id(s), annotation_id(s), subject_guid(s), object_guid(s), target_guid(s) or view(s)

Since elgg_get_river by default has a limit on the number of river items it fetches, if you wish to remove all river items you need to set limit to false

Access is ignored when deleting river items

Events are fired just before and after a river item has been deleted

Discussion replies moved to comments ¶

Since discussion replies where mostly a carbon copy of comments, all discussion replies have been migrated to comments. All related action, hooks, event, language keys etc. have been removed.

Bemerkung

Discussion comments will now show up in the Comments section of Search, no longer under the Discussion section.

Translations cleanup ¶

All plugins have been scanned for unused translation keys. The unused keys have been removed. If there was a generic translation available for the custom translation key, these have also been updated.

System Log ¶

System log API has been moved out of core into a system_log plugin. logbrowser and logrotate plugins have been merged into the system_log plugin.

Error logging ¶

Sending elgg_log() and PHP error messages to page output is now only possible via the developers plugin „Log to the screen“ setting. See the settings.example.php file for more information on using $CONFIG->debug in your settings.php file. Debugging should generally be done via the xdebug extension or tail -f /path/to/error.log on your server.

Composer asset plugin no longer required ¶

Assets are now loaded from https://asset-packagist.org. FXP composer asset plugin is no longer required when installing Elgg or updating composer dependencies.

Cron logs ¶

The cron logs are no longer stored in the database, but on the filesystem (in dataroot). This will allow longer output to be stored. A migration script was added to migrate the old database settings to the new location and remove the old values from the database.

Removed / changed language keys ¶

The language keys related to comment notifications have changed. Check the generic_comment:notification:owner: language keys

New MySQL schema features are not applied ¶

New 3.0 installations require MySQL 5.5.3 (or higher) and use the utf8mb4 character set and LONGTEXT content columns (notably allowing storing longer content and extended characters like emoji).

Miscellaneous changes ¶

The settings „Allow visitors to register“ and „Restrict pages to logged-in users“ now appear on the Basic Settings admin page.

Twitter API plugin ¶

The twitter_api plugin no longer comes bundled with Elgg.

Unit and Integration Testing ¶

Elgg’s PHPUnit bootstrap can now handle both unit and integration tests. Please note that you shouldn’t run tests on a production site, as it may damage data integrity. To prevent data loss, you need to specify database settings via environment variables. You can do so via the phpunit.xml bootstrap.

Plugins can now implement their own PHPUnit tests by extending \Elgg\UnitTestCase and \Elgg\IntegrationTestCase classes. plugins test suite will automatically autoload PHPUnit tests from mod/<plugin_id>/tests/phpunit/unit and mod/<plugin_id>/tests/phpunit/integration.

Prior to running integration tests, you need to enable the plugins that you wish to test alongside core API.

\Elgg\IntegrationTestCase uses \Elgg\Seeding trait, which can be used to conveniently build new entities and write them to the database.

\Elgg\UnitTestCase does not use the database, but provides a database mocking interface, which allows tests to define query specs with predefined returns.

By default, both unit and integration tests will be run whenever phpunit is called. You can use --testsuite flag to only run a specific suite: phpunit --testsuite unit or phpunit --testsuite integration or phpunit --testsuite plugins.

For integration testing to run properly, plugins are advised to not put any logic into the root of start.php, and instead return a Closure. This allows the testsuite to build a new Application instance without loosing plugin initialization logic.

Plugins with simpletests will continue working as perviously. However, method signatures in the ElggCoreUnitTest abstract class have changed and you will need to update your tests accordingly. Namely, it’s discouraged to use __construct and __desctruct methods. setUp and tearDown have been marked as private and are used for consistent test boostrapping and asserting pre and post conditions, your test case should use up and down methods instead.

Simpletests can no longer be executed from the admin interface of the developers plugin. Use Elgg cli command: elgg-cli simpletest

From 2.2 to 2.3¶

Contents

PHP Version
Deprecated APIs
Deprecated Views
New API for page and action handling
New API for working with file uploads
New API for manipulating images
New API for events
New API for signing URLs
Extendable form views
Metadata access_id
New API for extracting class names from arrays
Notifications
Entity list functions can output tables
Inline tabs components
API to alter registration and login URL
Support for fieldsets in forms
Lightbox

PHP Version ¶

PHP 5.5 has reached end of life in July 2016. To ensure that Elgg sites are secure, we now require PHP 5.6 for new installations.

Existing installations can continue using PHP 5.5 until Elgg 3.0.

In order to upgrade Elgg to 2.3 using composer while using PHP 5.5, you may need to use --ignore-platform-reqs flag.

Deprecated APIs ¶

Registering for to:object hook by the extender name: Use to:object, annotation and to:object, metadata hooks instead.

ajax_forward_hook(): No longer used as handler for ‚forward‘,‘all‘ hook. Ajax response is now wrapped by the ResponseFactory

ajax_action_hook(): No longer used as handler for ‚action‘,‘all‘ hook. Output buffering now starts before the hook is triggered in ActionsService

elgg_error_page_handler(): No longer used as a handler for ‚forward‘,<error_code> hooks

get_uploaded_file(): Use new file uploads API instead

get_user_notification_settings(): Use ElggUser::getNotificationSettings()

set_user_notification_setting(): Use ElggUser::setNotificationSetting()

pagesetup, system event: Use the menu or page shell hooks instead.

elgg.walled_garden JavaScript is deprecated: Use elgg/walled_garden AMD module instead.

elgg()->getDb()->getTableprefix(): Use elgg_get_config('dbprefix').

Private update_entity_last_action(): Refrain from manually updating last action timestamp.

Setting non-public access_id on metadata is deprecated. See below.

get_resized_image_from_existing_file(): Use elgg_save_resized_image().

get_resized_image_from_uploaded_file(): Use elgg_save_resized_image() in combination with upload API.

get_image_resize_parameters() will be removed.

elgg_view_input(): Use elgg_view_field(). Apologies for the API churn.

Deprecated Views ¶

resources/file/world: Use the resources/file/all view instead.

resources/pages/world: Use the resources/pages/all view instead.

walled_garden.js: Use the elgg/walled_garden module instead.

New API for page and action handling ¶

Page handlers and action script files should now return an instance of \Elgg\Http\ResponseBuilder. Plugins should use the following convenience functions to build responses:

elgg_ok_response() sends a 2xx response with HTML (page handler) or JSON data (actions)

elgg_error_response() sends a 4xx or 5xx response without content/data

elgg_redirect_response() silently redirects the request

New API for working with file uploads ¶

elgg_get_uploaded_files() - returns an array of Symfony uploaded file objects

ElggFile::acceptUploadedFile() - moves an uploaded file to Elgg’s filestore

New API for manipulating images ¶

New image manipulation service implements a more efficient approach to cropping and resizing images.

elgg_save_resized_image() - crops and resizes an image to preferred dimensions

New API for events ¶

elgg_clear_event_handlers() - similar to elgg_clear_plugin_hook_handlers this functions removes all registered event handlers

New API for signing URLs ¶

URLs can now be signed with a SHA-256 HMAC key and validated at any time before URL expiry. This feature can be used to tokenize action URLs in email notifications, as well as other uses outside of the Elgg installation.

elgg_http_get_signed_url() - signs the URL with HMAC key

elgg_http_validate_signed_url() - validates the signed URL

elgg_signed_request_gatekeeper() - gatekeeper that validates the signature of the current request

Extendable form views ¶

Form footer rendering can now be deferred until the form view and its extensions have finished rendering. This allows plugins to collaborate on form views without breaking the markup logic.

elgg_set_form_footer() - sets form footer for deferred rendering

elgg_get_form_footer() - returns currently set form footer

Metadata `access_id`¶

It’s now deprecated to create metadata with an explicit access_id value other than ACCESS_PUBLIC.

In Elgg 3.0, metadata will not be access controlled, and will be available in all contexts. If your plugin relies on access control of metadata, it would be wise to migrate storage to annotations or entities instead.

New API for extracting class names from arrays ¶

Similar to elgg_extract(), elgg_extract_class() extracts the „class“ key (if present), merges into existing class names, and always returns an array.

Notifications ¶

A high level 'prepare','notification' hook is now triggered for instant and subscription notifications and can be used to alter notification objects irrespective of their type.

'format','notification:<method>' hook is now triggered for instant and subscription notifications and can be used to format the notification (e.g. strip HTML tags, wrap the notification body in a template etc).

Instant notifications are now handled by the notifications service, hence almost all hooks applicable to subscription notifications also apply to instant notifications.

elgg_get_notification_methods() can be used to obtain registered notification methods

Added ElggUser::getNotificationSettings() and ElggUser::setNotificationSetting()

Entity list functions can output tables ¶

In functions like elgg_list_entities($options), table output is possible by setting $options['list_type'] = 'table' and providing an array of table columns as $options['columns']. Each column is an Elgg\Views\TableColumn object, usually created via methods on the service elgg()->table_columns.

Plugins can provide or alter these factory methods (see Elgg\Views\TableColumn\ColumnFactory). See the view admin/users/newest for a usage example.

Inline tabs components ¶

Inline tabs component can now be rendered with page/components/tabs view. The components allows to switch between pre-poluated and ajax-loaded. See page/components/tabs in core views and theme_sandbox/components/tabs in developers plugin for usage instructions and examples.

API to alter registration and login URL ¶

elgg_get_registration_url() should be used to obtain site’s registration URL

elgg_get_login_url() should be used to obtain site’s login URL

registration_url, site hook can be used to alter the default registration URL

login_url, site hook can be used to alter the default login URL

Support for fieldsets in forms ¶

elgg_view_field() replaces elgg_view_input(). It has a similar API, but accepts a single array.

elgg_view_field() supports #type, #label, #help and #class, allowing unprefixed versions to be sent to the input view $vars.

The new view input/fieldset can be used to render a set of fields, each rendered with elgg_view_field().

From 2.1 to 2.2¶

Contents

Deprecated APIs
Deprecated Views
Added elgg/popup module
Added elgg/lightbox module
Added elgg/embed module
New API for handling entity icons
Removed APIs
Improved elgg/ckeditor module

Deprecated APIs ¶

elgg.ui.river JavaScript library: Remove calls to elgg_load_js('elgg.ui.river') from plugin code. Update core/river/filter and forms/comment/save, if overwritten, to require component AMD modules

elgg.ui.popupOpen() and elgg.ui.popupClose() methods in elgg.ui JS library: Use elgg/popup module instead.

lightbox.js library: Do not use elgg_load_js('lightbox.js'); unless your code references deprecated elgg.ui.lightbox namespace. Use elgg/lightbox AMD module instead.

elgg.embed library and elgg.embed object: Do not use elgg_load_js('elgg.embed'). Use elgg/embed AMD module instead

Accessing icons_sizes config value directly: Use elgg_get_icon_sizes()

can_write_to_container(): Use ElggEntity::canWriteToContainer()

Deprecated Views ¶

elgg/ui.river.js is deprecated: Do not rely on simplecache URLs to work.

groups/js is deprecated: Use groups/navigation AMD module as a menu item dependency for „feature“ and „unfeature“ menu items instead.

lightbox/settings.js is deprecated: Use getOptions, ui.lightbox JS plugin hook or data-colorbox-opts attribute.

elgg/ckeditor/insert.js is deprecated: You no longer need to include it, hook registration takes place in elgg/ckeditor module

embed/embed.js is deprecated: Use elgg/embed AMD module.

Added `elgg/embed` module ¶

Even though rarely necessary, elgg/embed AMD module can be used to access the embed methods programmatically. The module bootstraps itself when necessary and is unlikely to require further decoration.

New API for handling entity icons ¶

ElggEntity now implements \Elgg\EntityIcon interface

elgg_get_icon_sizes() - return entity type/subtype specific icon sizes

ElggEntity::saveIconFromUploadedFile() - creates icons from an uploaded file

ElggEntity::saveIconFromLocalFile() - creates icons from a local file

ElggEntity::saveIconFromElggFile() - creates icons from an instance of ElggFile

ElggEntity::getIcon() - returns an instanceof ElggIcon that points to entity icon location on filestore (this may be just a placeholder, use ElggEntity::hasIcon() to validate if file has been written)

ElggEntity::deleteIcon() - deletes entity icons

ElggEntity::getIconLastChange() - return modified time of the icon file

ElggEntity::hasIcon() - checks if an icon with given size has been created

elgg_get_embed_url() - can be used to return an embed URL for an entity’s icon (served via /serve-icon handler)

User avatars are now served via serve-file handler. Plugins should start using elgg_get_inline_url() and note that:

/avatar/view page handler and resource view have been deprecated

/mod/profile/icondirect.php file has been deprecated

profile_set_icon_url() is no longer registered as a callback for "entity:icon:url","user" plugin hook

Group avatars are now served via serve-file handler. Plugins should start using elgg_get_inline_url() and note that:

groupicon page handler (groups_icon_handler()) has been deprecated

/mod/groups/icon.php file has been deprecated

File entity thumbs and downloads are now served via serve-file handler. Plugins should start using elgg_get_inline_url() and elgg_get_download_url() and note that:

file/download page handler and resource view have been deprecated

mod/file/thumbnail.php file has been deprecated

Several views have been updated to use new download URLs, including:

mod/file/views/default/file/specialcontent/audio/default.php

mod/file/views/default/file/specialcontent/image/default.php

mod/file/views/default/resources/file/view.php

mod/file/views/rss/file/enclosure.php

Removed APIs ¶

Just a warning that the private entity cache functions (e.g. _elgg_retrieve_cached_entity) have been removed. Some plugins may have been using them. Plugins should not use private APIs as they will more often be removed without notice.

Improved `elgg/ckeditor` module ¶

elgg/ckeditor module can now be used to add WYSIWYG to a textarea programmatically with elgg/ckeditor#bind.

From 2.0 to 2.1¶

Contents

Deprecated APIs
Application::getDb() changes
Added elgg/widgets module

Deprecated APIs ¶

ElggFile::setFilestore

get_default_filestore

set_default_filestore

elgg_get_config('siteemail'): Use elgg_get_site_entity()->email

URLs starting with /css/ and /js/: Use elgg_get_simplecache_url()

elgg.ui.widgets JavaScript object is deprecated by elgg/widgets AMD module

`Application::getDb()` changes ¶

If you’re using this low-level API, do not expect it to return an Elgg\Database instance in 3.0. It now returns an Elgg\Application\Database with many deprecated. These methods were never meant to be made public API, but we will do our best to support them in 2.x.

Added `elgg/widgets` module ¶

If your plugin code calls elgg.ui.widgets.init(), instead use the elgg/widgets module.

From 1.x to 2.0¶

Contents

Elgg can be now installed as a composer dependency instead of at document root
Cacheable views must have a file extension in their names
Dropped jquery-migrate and upgraded jquery to ^2.1.4
JS and CSS views have been moved out of the js/ and css/ directories
fxp/composer-asset-plugin is now required to install Elgg from source
List of deprecated views and view arguments that have been removed
All scripts moved to bottom of page
Attribute formatter removes keys with underscores
Breadcrumbs
Callbacks in Queries
Comments plugin hook
Container permissions hook
Creating or deleting a relationship triggers only one event
Discussion feature has been pulled from groups into its own plugin
Dropped login-over-https feature
Elgg has migrated from ext/mysql to PDO MySQL
Event/Hook calling order may change
export/ URLs are no longer available
Icons migrated to Font Awesome
Increase of z-index value in elgg-menu-site class
input/autocomplete view
Introduced third-party library for sending email
Label elements
Plugin Aalborg Theme
Plugin Likes
Plugin Messages
Plugin Blog
Plugin Bookmarks
Plugin File
Removed Classes
Removed keys available via elgg_get_config()
Removed Functions
Removed methods
Removed Plugin Hooks
Removed Actions
Removed Views
Removed View Variables
Removed libraries
Specifying View via Properties
Viewtype is static after the initial elgg_get_viewtype() call
Deprecations

Elgg can be now installed as a composer dependency instead of at document root ¶

That means an Elgg site can look something like this:

settings.php
vendor/
  elgg/
    elgg/
      engine/
        start.php
      _graphics/
        elgg_sprites.png
mod/
  blog
  bookmarks
  ...

elgg_get_root_path and $CONFIG->path will return the path to the application root directory, which is not necessarily the same as Elgg core’s root directory (which in this case is vendor/elgg/elgg/).

Do not attempt to access the core Elgg from your plugin directly, since you cannot rely on its location on the filesystem.

In particular, don’t try load engine/start.php.

// Don't do this!
dirname(__DIR__) . "/engine/start.php";

To boot Elgg manually, you can use the class Elgg\Application.

// boot Elgg in mod/myplugin/foo.php
require_once dirname(dirname(__DIR__)) . '/vendor/autoload.php';
\Elgg\Application::start();

However, use this approach sparingly. Prefer Routing instead whenever possible as that keeps your public URLs and your filesystem layout decoupled.

Also, don’t try to access the _graphics files directly.

readfile(elgg_get_root_path() . "_graphics/elgg_sprites.png");

Use Views instead:

echo elgg_view('elgg_sprites.png');

Cacheable views must have a file extension in their names ¶

This requirement makes it possibile for us to serve assets directly from disk for performance, instead of serving them through PHP.

It also makes it much easier to explore the available cached resources by navigating to dataroot/views_simplecache and browsing around.

Bad: my/cool/template

Good: my/cool/template.html

We now cache assets by "$viewtype/$view", not md5("$viewtype|$view"), which can result in conflicts between cacheable views that don’t have file extensions to disambiguate files from directories.

Dropped `jquery-migrate` and upgraded `jquery` to ^2.1.4 ¶

jQuery 2.x is API-compatible with 1.x, but drops support for IE8-, which Elgg hasn’t supported for some time anyways.

See http://jquery.com/upgrade-guide/1.9/ for how to move off jquery-migrate.

If you’d prefer to just add it back, you can use this code in your plugin’s init:

elgg_register_js('jquery-migrate', elgg_get_simplecache_url('jquery-migrate.js'), 'head');
elgg_load_js('jquery-migrate');

Also, define a jquery-migrate.js view containing the contents of the script.

JS and CSS views have been moved out of the js/ and css/ directories ¶

They also have been given .js and .css extensions respectively if they didn’t already have them:

Old view	New view
`js/view`	`view.js`
`js/other.js`	`other.js`
`css/view`	`view.css`
`css/other.css`	`other.css`
`js/img.png`	`img.png`

The main benefit this brings is being able to co-locate related assets. So a template (view.php) can have its CSS/JS dependencies right next to it (view.css, view.js).

Care has been taken to make this change as backwards-compatible as possible, so you should not need to update any view references right away. However, you are certainly encouraged to move your JS and CSS views to their new, canonical locations.

Practically speaking, this carries a few gotchas:

The view_vars, $view_name and view, $view_name hooks will operate on the canonical view name:

elgg_register_plugin_hook_handler('view', 'css/elgg', function($hook, $view_name) {
  assert($view_name == 'elgg.css') // not "css/elgg"
});

Using the view, all hook and checking for individual views may not work as intended:

elgg_register_plugin_hook_handler('view', 'all', function($hook, $view_name) {
  // Won't work because "css/elgg" was aliased to "elgg.css"
  if ($view_name == 'css/elgg') {
    // Never executed...
  }

  // Won't work because no canonical views start with css/* anymore
  if (strpos($view_name, 'css/') === 0) {
    // Never executed...
  }
});

Please let us know about any other BC issues this change causes. We’d like to fix as many as possible to make the transition smooth.

`fxp/composer-asset-plugin` is now required to install Elgg from source ¶

We use fxp/composer-asset-plugin to manage our browser assets (js, css, html) with Composer, but it must be installed globally before installing Elgg in order for the bower-asset/* packages to be recognized. To install it, run:

composer global require fxp/composer-asset-plugin

If you don’t do this before running composer install or composer create-project, you will get an error message:

[InvalidArgumentException]
Package fxp/composer-asset-plugin not found

List of deprecated views and view arguments that have been removed ¶

We dropped support for and/or removed the following views:

canvas/layouts/*

categories

categories/view

core/settings/tools

embed/addcontentjs

footer/analytics (Use page/elements/foot instead)

groups/left_column

groups/right_column

groups/search/finishblurb

groups/search/startblurb

input/calendar (Use input/date instead)

input/datepicker (Use input/date instead)

input/pulldown (Use input/select instead)

invitefriends/formitems

js/admin (Use AMD and elgg_require_js instead of extending JS views)

js/initialise_elgg (Use AMD and elgg_require_js instead of extending JS views)

members/nav

metatags (Use the ‚head‘, ‚page‘ plugin hook instead)

navigation/topbar_tools

navigation/viewtype

notifications/subscriptions/groupsform

object/groupforumtopic

output/calendar (Use output/date instead)

output/confirmlink (Use output/url instead)

page_elements/contentwrapper

page/elements/shortcut_icon (Use the ‚head‘, ‚page‘ plugin hook instead)

page/elements/wrapper

profile/icon (Use elgg_get_entity_icon)

river/object/groupforumtopic/create

settings/{plugin}/edit (Use plugins/{plugin}/settings instead)

user/search/finishblurb

user/search/startblurb

usersettings/{plugin}/edit (Use plugins/{plugin}/usersettings instead)

widgets/{handler}/view (Use widgets/{handler}/content instead)

We also dropped the following arguments to views:

„value“ in output/iframe (Use „src“ instead)

„area2“ and „area3“ in page/elements/sidebar (Use „sidebar“ or view extension instead)

„js“ in icon views (e.g. icon/user/default)

„options“ to input/radio and input/checkboxes which aren’t key-value pairs will no longer be acceptable.

All scripts moved to bottom of page ¶

You should test your plugin with the JavaScript error console visible. For performance reasons, Elgg no longer supports script elements in the head element or in HTML views. elgg_register_js will now load all scripts at the end of the body element.

You must convert inline scripts to AMD or to external scripts loaded with elgg_load_js.

Early in the page, Elgg provides a shim of the RequireJS require() function that simply queues code until the AMD elgg and jQuery modules are defined. This provides a straightforward way to convert many inline scripts to use require().

Inline code which will fail because the stack is not yet loaded:

<script>
$(function () {
    // code using $ and elgg
});
</script>

This should work in Elgg 2.0:

<script>
require(['elgg', 'jquery'], function (elgg, $) {
    $(function () {
        // code using $ and elgg
    });
});
</script>

Attribute formatter removes keys with underscores ¶

elgg_format_attributes() (and all APIs that use it) now filter out attributes whose name contains an underscore. If the attribute begins with data-, however, it will not be removed.

Breadcrumbs ¶

Breadcrumb display now removes the last item if it does not contain a link. To restore the previous behavior, replace the plugin hook handler elgg_prepare_breadcrumbs with your own:

elgg_unregister_plugin_hook_handler('prepare', 'breadcrumbs', 'elgg_prepare_breadcrumbs');
elgg_register_plugin_hook_handler('prepare', 'breadcrumbs', 'myplugin_prepare_breadcrumbs');

function myplugin_prepare_breadcrumbs($hook, $type, $breadcrumbs, $params) {
    // just apply excerpt to titles
    foreach (array_keys($breadcrumbs) as $i) {
        $breadcrumbs[$i]['title'] = elgg_get_excerpt($breadcrumbs[$i]['title'], 100);
    }
    return $breadcrumbs;
}

Callbacks in Queries ¶

Make sure to use only valid callable values for „callback“ argument/options in the API.

Querying functions will now will throw a RuntimeException if is_callable() returns false for the given callback value. This includes functions such as elgg_get_entities(), get_data(), and many more.

Comments plugin hook ¶

Plugins can now return an empty string from 'comments',$entity_type hook in order to override the default comments component view. To force the default comments component, your plugin must return false. If you were using empty strings to force the default comments view, you need to update your hook handlers to return false.

Container permissions hook ¶

The behavior of the container_permissions_check hook has changed when an entity is being created: Before 2.0, the hook would be called twice if the entity’s container was not the owner. On the first call, the entity’s owner would be passed in as $params['container'], which could confuse handlers.

In 2.0, when an entity is created in a container like a group, if the owner is the same as the logged in user (almost always the case), this first check is bypassed. So the container_permissions_check hook will almost always be called once with $params['container'] being the correct container of the entity.

Creating or deleting a relationship triggers only one event ¶

The „create“ and „delete“ relationship events are now only fired once, with "relationship" as the object type.

E.g. Listening for the "create", "member" or "delete", "member" event(s) will no longer capture group membership additions/removals. Use the "create", "relationship" or "delete", "relationship" events.

Discussion feature has been pulled from groups into its own plugin ¶

The object, groupforumtopic subtype has been replaced with the object, discussion subtype. If your plugin is using or altering the old discussion feature, you should upgrade it to use the new subtype.

Nothing changes from the group owners‘ point of view. The discussion feature is still available as a group tool and all old discussions are intact.

Elgg has migrated from ext/mysql to PDO MySQL ¶

Elgg now uses a PDO_MYSQL connection and no longer uses any ext/mysql functions. If you use mysql_* functions, implicitly relying on an open connection, these will fail.

If your code uses one of the following functions, read below.

execute_delayed_write_query()
execute_delayed_read_query()

If you provide a callable $handler to be called with the results, your handler will now receive a \Doctrine\DBAL\Driver\Statement object. Formerly this was an ext/mysql result resource.

Event/Hook calling order may change ¶

When registering for events/hooks, the all keyword for wildcard matching no longer has any effect on the order that handlers are called. To ensure your handler is called last, you must give it the highest priority of all matching handlers, or to ensure your handler is called first, you must give it the lowest priority of all matching handlers.

If handlers were registered with the same priority, these are called in the order they were registered.

To emulate prior behavior, Elgg core handlers registered with the all keyword have been raised in priority. Some of these handlers will most likely be called in a different order.

`export/` URLs are no longer available ¶

Elgg no longer provides this endpoint for exposing resource data.

Icons migrated to Font Awesome ¶

Elgg’s sprites and most of the CSS classes beginning with elgg-icon- have been removed.

Usage of elgg_view_icon() is backward compatible, but static HTML using the elgg-icon classes will have to be updated to the new markup.

input/autocomplete view ¶

Plugins that override the input/autocomplete view will need to include the source URL in the data-source attribute of the input element, require the new elgg/autocomplete AMD module, and call its init method. The 1.x javascript library elgg.autocomplete is no longer used.

Introduced third-party library for sending email ¶

We are using the excellent Zend\Mail library to send emails in Elgg 2.0. There are likely edge cases that the library handles differently than Elgg 1.x. Take care to test your email notifications carefully when upgrading to 2.0.

Label elements ¶

The following views received label elements around some of the input fields. If your plugin/theme overrides these views please check for the new content.

views/default/core/river/filter.php
views/default/forms/admin/plugins/filter.php
views/default/forms/admin/plugins/sort.php
views/default/forms/login.php

Plugin Aalborg Theme ¶

The view page/elements/navbar now uses a Font Awesome icon for the mobile menu selector instead of an image. The bars.png image and supporting CSS for the 1.12 rendering has been removed, so update your theme accordingly.

Plugin Likes ¶

Objects are no longer likable by default. To support liking, you can register a handler to permit the annotation, or more simply register for the hook ["likes:is_likable", "<type>:<subtype>"] and return true. E.g.

elgg_register_plugin_hook_handler('likes:is_likable', 'object:mysubtype', 'Elgg\Values::getTrue');

Just as before, the permissions_check:annotate hook is still called and may be used to override default behavior.

Plugin Messages ¶

If you’ve removed or replaced the handler function messages_notifier to hide/alter the inbox icon, you’ll instead need to do the same for the topbar menu handler messages_register_topbar. messages_notifier is no longer used to add the menu link.

Messages will no longer get the metadata ‚msg‘ for newly created messages. This means you can not rely on that metadata to exist.

Plugin Blog ¶

The blog pages showing ‚Mine‘ or ‚Friends‘ listings of blogs have been changed to list all the blogs owned by the users (including those created in groups).

Plugin Bookmarks ¶

The bookmark pages showing ‚Mine‘ or ‚Friends‘ listings of bookmarks have been changed to list all the bookmarks owned by the users (including those created in groups).

Plugin File ¶

The file pages showing ‚Mine‘ or ‚Friends‘ listings of files have been changed to list all the files owned by the users (including those created in groups).

Removed Classes ¶

ElggInspector

Notable

FilePluginFile: replace with ElggFile (or load with get_entity())

Removed keys available via `elgg_get_config()`¶

allowed_ajax_views

dataroot_in_settings

externals

externals_map

i18n_loaded_from_cache

language_paths

pagesetupdone

registered_tag_metadata_names

simplecache_enabled_in_settings

translations

viewpath

views

view_path

viewtype

wordblacklist

Also note that plugins should not be accessing the global $CONFIG variable except for in settings.php.

Removed Functions ¶

blog_get_page_content_friends

blog_get_page_content_read

count_unread_messages()

delete_entities()

delete_object_entity()

delete_user_entity()

elgg_get_view_location()

elgg_validate_action_url()

execute_delayed_query()

extend_view()

get_db_error()

get_db_link()

get_entities()

get_entities_from_access_id()

get_entities_from_access_collection()

get_entities_from_annotations()

get_entities_from_metadata()

get_entities_from_metadata_multi()

get_entities_from_relationship()

get_filetype_cloud()

get_library_files()

get_views()

is_ip_in_array()

list_entities()

list_entities_from_annotations()

list_group_search()

list_registered_entities()

list_user_search()

load_plugins()

menu_item()

make_register_object()

mysql_*(): Elgg no longer uses ext/mysql

remove_blacklist()

search_for_group()

search_for_object()

search_for_site()

search_for_user()

search_list_objects_by_name()

search_list_groups_by_name()

search_list_users_by_name()

set_template_handler()

test_ip()

Removed methods ¶

ElggCache::set_variable()

ElggCache::get_variable()

ElggData::initialise_attributes()

ElggData::getObjectOwnerGUID()

ElggDiskFilestore::make_directory_root()

ElggDiskFilestore::make_file_matrix()

ElggDiskFilestore::user_file_matrix()

ElggDiskFilestore::mb_str_split()

ElggEntity::clearMetadata()

ElggEntity::clearRelationships()

ElggEntity::clearAnnotations()

ElggEntity::getOwner()

ElggEntity::setContainer()

ElggEntity::getContainer()

ElggEntity::getIcon()

ElggEntity::setIcon()

ElggExtender::getOwner()

ElggFileCache::create_file()

ElggObject::addToSite(): parent function in ElggEntity still available

ElggObject::getSites(): parent function in ElggEntity still available

ElggSite::getCollections()

ElggUser::addToSite(): parent function in ElggEntity still available

ElggUser::getCollections()

ElggUser::getOwner()

ElggUser::getSites(): parent function in ElggEntity still available

ElggUser::listFriends()

ElggUser::listGroups()

ElggUser::removeFromSite(): parent function in ElggEntity still available

The following arguments have also been dropped:

ElggSite::getMembers() - 2: $offset

elgg_view_entity_list() - 3: $offset - 4: $limit - 5: $full_view - 6: $list_type_toggle - 7: $pagination

Removed Plugin Hooks ¶

[display, view]: See the new plugin hook.

Removed Actions ¶

widgets/upgrade

Removed Views ¶

forms/admin/plugins/change_state

Removed View Variables ¶

During rendering, the view system no longer injects these into the scope:

$vars['url']: replace with elgg_get_site_url()

$vars['user']: replace with elgg_get_logged_in_user_entity()

$vars['config']: use elgg_get_config() and elgg_set_config()

$CONFIG: use elgg_get_config() and elgg_set_config()

Also several workarounds for very old views are no longer performed. Make these changes:

Set $vars['full_view'] instead of $vars['full'].

Set $vars['name'] instead of $vars['internalname'].

Set $vars['id'] instead of $vars['internalid'].

Removed libraries ¶

elgg:markdown: Elgg no longer provides a markdown implementation. You must provide your own.

Specifying View via Properties ¶

The metadata $entity->view no longer specifies the view used to render in elgg_view_entity().

Similarly the property $annotation->view no longer has an effect within elgg_view_annotation().

Viewtype is static after the initial `elgg_get_viewtype()` call ¶

elgg_set_viewtype() must be used to set the viewtype at runtime. Although Elgg still checks the view input and $CONFIG->view initially, this is only done once per request.

Deprecations ¶

It’s deprecated to read or write to metadata keys starting with filestore:: on ElggFile objects. In Elgg 3.0 this metadata will be deleted if it points to the current data root path, so few file objects will have it. Plugins should only use ElggFile::setFilestore if files need to be stored in a custom location.

Bemerkung

This is not the only deprecation in Elgg 2.0. Plugin developers should watch their site error logs.

From 1.10 to 1.11¶

Contents

Comment highlighting

Comment highlighting ¶

If your theme is using the file views/default/css/elements/components.php, you must add the following style definitions in it to enable highlighting for comments and discussion replies:

.elgg-comments .elgg-state-highlight {
        -webkit-animation: comment-highlight 5s;
        animation: comment-highlight 5s;
}
@-webkit-keyframes comment-highlight {
        from {background: #dff2ff;}
        to {background: white;}
}
@keyframes comment-highlight {
        from {background: #dff2ff;}
        to {background: white;}
}

From 1.9 to 1.10¶

Contents

File uploads

File uploads ¶

If your plugin is using a snippet copied from the file/upload action to fix detected mime types for Microsoft zipped formats, it can now be safely removed.

If your upload action performs other manipulations on detected mime and simple types, it is recommended to make use of available plugin hooks:

'mime_type','file' for filtering detected mime types
'simple_type','file' for filtering parsed simple types

From 1.8 to 1.9¶

Contents

The manifest file
$CONFIG and $vars[‚config‘]
Language files
Notifications
Adding items to the Activity listing
Entity URL handlers
Web services

In the examples we are upgrading an imaginary „Photos“ plugin.

Only the key changes are included. For example some of the deprecated functions are not mentioned here separately.

Each section will include information whether the change is backwards compatible with Elgg 1.8.

The manifest file ¶

No changes are needed if your plugin is compatible with 1.8.

It’s however recommended to add the <id> tag. It’s value should be the name of the directory where the plugin is located inside the mod/ directory.

If you make changes that break BC, you must update the plugin version and the required Elgg release.

Example of (shortened) old version:

<?xml version="1.0" encoding="UTF-8"?>
<plugin_manifest xmlns="http://www.elgg.org/plugin_manifest/1.8">
    <name>Photos</name>
    <author>John Doe</author>
    <version>1.0</version>
    <description>Adds possibility to upload photos and arrange them into albums.</description>
    <requires>
        <type>elgg_release</type>
        <version>1.8</version>
    </requires>
</plugin_manifest>

Example of (shortened) new version:

<?xml version="1.0" encoding="UTF-8"?>
<plugin_manifest xmlns="http://www.elgg.org/plugin_manifest/1.8">
    <name>Photos</name>
    <id>photos</id>
    <author>John Doe</author>
    <version>2.0</version>
    <description>Adds possibility to upload photos and arrange them into albums.</description>
    <requires>
        <type>elgg_release</type>
        <version>1.9</version>
    </requires>
</plugin_manifest>

$CONFIG and $vars[‚config‘]¶

Both the global $CONFIG variable and the $vars['config'] parameter have been deprecated. They should be replaced with the elgg_get_config() function.

Example of old code:

// Using the global $CONFIG variable:
global $CONFIG;
$plugins_path = $CONFIG->plugins_path

// Using the $vars view parameter:
$plugins_path = $vars['plugins_path'];

Example of new code:

$plugins_path = elgg_get_config('plugins_path');

Bemerkung

Compatible with 1.8

Bemerkung

See how the community_plugins plugin was updated: https://github.com/Elgg/community_plugins/commit/f233999bbd1478a200ee783679c2e2897c9a0483

Language files ¶

In Elgg 1.8 the language files needed to use the add_translation() function. In 1.9 it is enough to just return the array that was previously passed to the function as a parameter. Elgg core will use the file name (e.g. en.php) to tell which language the file contains.

Example of the old way in languages/en.php:

$english = array(
    'photos:all' => 'All photos',
);
add_translation('en', $english);

Example of new way:

return array(
    'photos:all' => 'All photos',
);

Warnung

Not compatible with 1.8

Notifications ¶

One of the biggest changes in Elgg 1.9 is the notifications system. The new system allows more flexible and scalable way of sending notifications.

Example of the old way:

function photos_init() {
    // Tell core that we want to send notifications about new photos
    register_notification_object('object', 'photo', elgg_echo('photo:new'));

    // Register a handler that creates the notification message
    elgg_register_plugin_hook_handler('notify:entity:message', 'object', 'photos_notify_message');
}

/**
 * Set the notification message body
 *
 * @param string $hook    Hook name
 * @param string $type    Hook type
 * @param string $message The current message body
 * @param array  $params  Parameters about the photo
 * @return string
 */
function photos_notify_message($hook, $type, $message, $params) {
    $entity = $params['entity'];
    $to_entity = $params['to_entity'];
    $method = $params['method'];
    if (elgg_instanceof($entity, 'object', 'photo')) {
        $descr = $entity->excerpt;
        $title = $entity->title;
        $owner = $entity->getOwnerEntity();
        return elgg_echo('photos:notification', array(
            $owner->name,
            $title,
            $descr,
            $entity->getURL()
        ));
    }
    return null;
}

Example of the new way:

function photos_init() {
    elgg_register_notification_event('object', 'photo', array('create'));
    elgg_register_plugin_hook_handler('prepare', 'notification:publish:object:photo', 'photos_prepare_notification');
}

/**
 * Prepare a notification message about a new photo
 *
 * @param string                          $hook         Hook name
 * @param string                          $type         Hook type
 * @param Elgg_Notifications_Notification $notification The notification to prepare
 * @param array                           $params       Hook parameters
 * @return Elgg_Notifications_Notification
 */
function photos_prepare_notification($hook, $type, $notification, $params) {
    $entity = $params['event']->getObject();
    $owner = $params['event']->getActor();
    $recipient = $params['recipient'];
    $language = $params['language'];
    $method = $params['method'];

    // Title for the notification
    $notification->subject = elgg_echo('photos:notify:subject', array($entity->title), $language);

    // Message body for the notification
    $notification->body = elgg_echo('photos:notify:body', array(
        $owner->name,
        $entity->title,
        $entity->getExcerpt(),
        $entity->getURL()
    ), $language);

    // The summary text is used e.g. by the site_notifications plugin
    $notification->summary = elgg_echo('photos:notify:summary', array($entity->title), $language);

    return $notification;
}

Warnung

Not compatible with 1.8

Bemerkung

See how the community_plugins plugin was updated to use the new system: https://github.com/Elgg/community_plugins/commit/bfa356cfe8fb99ebbca4109a1b8a1383b70ff123

Notifications can also be sent with the notify_user() function.

It has however been updated to support three new optional parameters passed inside an array as the fifth parameter.

The parameters give notification plugins more control over the notifications, so they should be included whenever possible. For example the bundled site_notifications plugin won’t work properly if the parameters are missing.

Parameters:

object The object that we are notifying about (e.g. ElggEntity or ElggAnnotation). This is needed so that notification plugins can provide a link to the object.
action String that describes the action that triggered the notification (e.g. „create“, „update“, etc).
summary String that contains a summary of the notification. (It should be more informative than the notification subject but less informative than the notification body.)

Example of the old way:

// Notify $owner that $user has added a $rating to an $entity created by him

$subject = elgg_echo('rating:notify:subject');
$body = elgg_echo('rating:notify:body', array(
        $owner->name,
        $user->name,
        $entity->title,
        $entity->getURL(),
));

notify_user($owner->guid,
                        $user->guid,
                        $subject,
                        $body
                );

Example of the new way:

// Notify $owner that $user has added a $rating to an $entity created by him

$subject = elgg_echo('rating:notify:subject');
$summary = elgg_echo('rating:notify:summary', array($entity->title));
$body = elgg_echo('rating:notify:body', array(
        $owner->name,
        $user->name,
        $entity->title,
        $entity->getURL(),
));

$params = array(
        'object' => $rating,
        'action' => 'create',
        'summary' => $summary,
);

notify_user($owner->guid,
                        $user->guid,
                        $subject,
                        $body,
                        $params
                );

Bemerkung

Compatible with 1.8

Adding items to the Activity listing ¶

add_to_river('river/object/photo/create', 'create', $user_guid, $photo_guid);

elgg_create_river_item(array(
    'view' => 'river/object/photo/create',
    'action_type' => 'create',
    'subject_guid' => $user_guid,
    'object_guid' => $photo_guid,
));

You can also add the optional target_guid parameter which tells the target of the create action.

If the photo would had been added for example into a photo album, we could add it by passing in also:

'target_guid' => $album_guid,

Warnung

Not compatible with 1.8

Entity URL handlers ¶

The elgg_register_entity_url_handler() function has been deprecated. In 1.9 you should use the 'entity:url', 'object' plugin hook instead.

Example of the old way:

/**
 * Initialize the photo plugin
 */
my_plugin_init() {
    elgg_register_entity_url_handler('object', 'photo', 'photo_url_handler');
}

/**
 * Returns the URL from a photo entity
 *
 * @param ElggEntity $entity
 * @return string
 */
function photo_url_handler($entity) {
    return "photo/view/{$entity->guid}";
}

Example of the new way:

/**
 * Initialize the photo plugin
 */
my_plugin_init() {
    elgg_register_plugin_hook_handler('entity:url', 'object', 'photo_url_handler');
}

/**
 * Returns the URL from a photo entity
 *
 * @param string $hook   'entity:url'
 * @param string $type   'object'
 * @param string $url    The current URL
 * @param array  $params Hook parameters
 * @return string
 */
function photo_url_handler($hook, $type, $url, $params) {
    $entity = $params['entity'];

    // Check that the entity is a photo object
    if ($entity->getSubtype() !== 'photo') {
        // This is not a photo object, so there's no need to go further
        return;
    }

    return "photo/view/{$entity->guid}";
}

Warnung

Not compatible with 1.8

Web services ¶

In Elgg 1.8 the web services API was included in core and methods were exposed using expose_function(). To enable the same functionality for Elgg 1.9, enable the „Web services 1.9“ plugin and replace all calls to expose_function() with elgg_ws_expose_function().

From 1.7 to 1.8¶

Contents

Updating core
Updating plugins

Elgg 1.8 is the biggest leap forward in the development of Elgg since version 1.0. As such, there is more work to update core and plugins than with previous upgrades. There were a small number of API changes and following our standard practice, the methods we deprecated have been updated to work with the new API. The biggest changes are in the standardization of plugins and in the views system.

Updating core ¶

Delete the following core directories (same level as _graphics and engine):

_css
account
admin
dashboard
entities
friends
search
settings
simplecache
views

Warnung

If you do not delete these directories before an upgrade, you will have problems!

Updating plugins ¶

Use standardized routing with page handlers¶

All: /page_handler/all
User’s content: /page_handler/owner/:username
User’s friends‘ content: /page_handler/friends/:username
Single entity: /page_handler/view/:guid/:title
Added: /page_handler/add/:container_guid
Editing: /page_handler/edit/:guid
Group list: /page_handler/group/:guid/all

Include page handler scripts from the page handler¶

Almost every page handler should have a page handler script. (Example: bookmarks/all => mod/bookmarks/pages/bookmarks/all.php)

Call set_input() for entity guids in the page handler and use get_input() in the page handler scripts.
Call gatekeeper() and admin_gatekeeper() in the page handler function if required.
The group URL should use the pages/:handler/owner.php script.
Page handlers should not contain HTML.
Update the URLs throughout the plugin. (Don’t forget to remove /pg/!)

Use standardized page handlers and scripts¶

Store page handler scripts in mod/:plugin/pages/:page_handler/:page_name.php

Use the content page layout in page handler scripts:

$content = elgg_view_layout('content', $options);

Page handler scripts should not contain HTML.
Call elgg_push_breadcrumb() in the page handler scripts.
No need to set page owner if the URLs are in the standardized format.
For group content, check the container_guid by using elgg_get_page_owner_entity().

The object/:subtype view¶

Make sure there are views for $vars['full_view'] == true and $vars['full_view'] == false. $vars['full_view'] replaced $vars['full].
Check for the object in $vars['entity']. Use elgg_instance_of() to make sure it’s the type of entity you want.
Return true to short circuit the view if the entity is missing or wrong.
Use elgg_view('object/elements/summary', array('entity' => $entity)); and elgg_view_menu('entity', array('entity' => $entity)); to help format. You should use very little markup in these views.

Update action structure¶

Namespace action files and action names (example: mod/blog/actions/blog/save.php => action/blog/save)
Use the following action URLs:
- Add: action/:plugin/save
- Edit: action/:plugin/save
- Delete: action/:plugin/delete
Make the delete action accept action/:handler/delete?guid=:guid so the metadata entity menu has the correct URL by default.

Update deprecated functions¶

Functions deprecated in 1.7 will produce visible errors in 1.8.
You can also update functions deprecated in 1.8.
- Many registration functions simply added an elgg_ prefix for consistency, and should be easy to update.
- See /engine/lib/deprecated-1.8.php for the full list.
- You can set the debug level to “warning” to get visual reminders of deprecated functions.

Update the group profile module¶

Use the blog or file plugins for examples. This will help with making your plugin themeable by the new CSS framework.

Update forms¶

Move form bodies to the forms/:action view to use Evan’s new elgg_view_form.
Use input views in form bodies rather than html. This helps with theming and future-proofing.
Add a function that prepares the form (see mod/file/lib/file.php for an example)
Make your forms sticky (see the file plugin’s upload action and form prepare function).

The forms API is discussed in more detail in Forms + Actions.

Clean up CSS/HTML¶

We have added many CSS patterns to the base CSS file (modules, image block, spacing primitives). We encourage you to use these patterns and classes wherever possible. Doing so should:

Reduce maintenance costs, since you can delete most custom CSS.
Make your plugin more compatible with community themes.

Look for patterns that can be moved into core if you need significant CSS.

We use hyphens rather than underscores in classes/ids and encourage you do the same for consistency.

If you do need your own CSS, you should use your own namespace, rather than elgg-.

Update manifest.xml¶

Use http://el.gg/manifest17to18 to automate this.
Don’t use the „bundled“ category with your plugins. That is only for plugins distributed with Elgg.

Update settings and user settings views¶

The view for settings is now plugins/:plugin/settings (previously settings/:plugin/edit).
The view for user settings is now plugins/:plugin/usersettings (previously usersettings/:plugin/edit).

FAQs and Other Troubleshooting¶

Below are some commonly asked questions about Elgg.

Contents

General
Security
Development

General¶

Siehe auch

Getting Help

„Plugin cannot start and has been deactivated“ or „This plugin is invalid“¶

This error is usually accompanied by more details explaining why the plugin is invalid. This is usually caused by an incorrectly installed plugin.

If you are installing a plugin called „test“, there will be a test directory under mod. In that test directory there needs to be a manifest.xml file /mod/test/manifest.xml.

If this file does not exist, it could be caused by:

installing a plugin to the wrong directory
creating a directory under /mod that does not contain a plugin
a bad ftp transfer
unzipping a plugin into an extra directory (myplugin.zip unzips to myplugin/myplugin)

If you are on a Unix-based host and the files exist in the correct directory, check the permissions. Elgg must have read access to the files and read + execute access on the directories.

White Page (WSOD)¶

A blank, white page (often called a „white screen of death“) means there is a PHP syntax error. There are a few possible causes of this:

corrupted file - try transfering the code again to your server
a call to a php module that was not loaded - this can happen after you install a plugin that requires a specific module.
bad plugin - not all plugins have been written to the same quality so you should be careful which ones you install.

To find where the error is occurring, change the .htaccess file to display errors to the browser. Set display_errors to 1 and load the same page again. You should see a PHP error in your browser. Change the setting back once you’ve resolved the problem.

Bemerkung

If you are using the Developer’s Tools plugin, go to its settings page and make sure you have „Display fatal PHP errors“ enabled.

If the white screen is due to a bad plugin, remove the latest plugins that you have installed by deleting their directories and then reload the page.

Bemerkung

You can temporarily disable all plugins by creating an empty file at mod/disabled. You can then disable the offending module via the administrator tools panel.

If you are getting a WSOD when performing an action, like logging in or posting a blog, but there are no error messages, it’s most likely caused by non-printable characters in plugin code. Check the plugin for white spaces/new lines characters after finishing php tag (?>) and remove them.

Page not found¶

If you have recently installed your Elgg site, the most likely cause for a page not found error is that mod_rewrite is not setup correctly on your server. There is information in the Install Troubleshooting page on fixing this. The second most likely cause is that your site url in your database is incorrect.

If you’ve been running your site for a while and suddenly start getting page not found errors, you need to ask yourself what has changed. Have you added any plugins? Did you change your server configuration?

To debug a page not found error:

Confirm that the link leading to the missing page is correct. If not, how is that link being generated?
Confirm that the .htaccess rewrite rules are being picked up.

Login token mismatch¶

If you have to log in twice to your site and the error message after the first attempt says there was a token mismatch error, the URL in Elgg’s settings does not match the URL used to access it. The most common cause for this is adding or removing the „www“ when accessing the site. For example, www.elgg.org vs elgg.org. This causes a problem with session handling because of the way that web browsers save cookies.

To fix this, you can add rewrite rules. To redirect from www.elgg.org to elgg.org in Apache, the rules might look like:

RewriteCond %{HTTP_HOST} .
RewriteCond %{HTTP_HOST} !^elgg\.org
RewriteRule (.*) http://elgg.org/$1 [R=301,L]

Redirecting from non-www to www could look like this:

RewriteCond %{HTTP_HOST} ^elgg\.org
RewriteRule ^(.*)$ http://www.elgg.org/$1 [R=301,L]

If you don’t know how to configure rewrite rules, ask your host for more information.

Form is missing token or ts fields¶

All Elgg actions require a security token, and this error occurs when that token is missing. This is either a problem with your server configuration or with a 3rd party plugin.

If you experience this on a new installation, make sure that your server is properly configured and your rewrite rules are correct. If you experience this on an upgrade, make sure you have updated your rewrite rules either in .htaccess (Apache) or in the server configuration.

If you are experiencing this, disable all 3rd party plugins and try again. Very old plugins for Elgg don’t use security tokens. If the problem goes away when plugins are disabled, it’s due to a plugin that should be updated by its author.

Maintenance mode¶

To take your site temporarily offline, go to Administration -> Utilities -> Maintenance Mode. Complete the form and hit save to disable your site for everyone except admin users.

Missing email¶

If your users are reporting that validation emails are not showing up, have them check their spam folder. It is possible that the emails coming from your server are being marked as spam. This depends on many factors such as whether your hosting provider has a problem with spammers, how your PHP mail configuration is set up, what mail transport agent your server is using, or your host limiting the number of email that you can send in an hour.

If no one gets email at all, it is quite likely your server is not configured properly for email. Your server needs a program to send email (called a Mail Transfer Agent - MTA) and PHP must be configured to use the MTA.

To quickly check if PHP and an MTA are correctly configured, create a file on your server with the following content:

<?php
$address = "your_email@your_host.com";

$subject = 'Test email.';

$body = 'If you can read this, your email is working.';

echo "Attempting to email $address...<br />";

if (mail($address, $subject, $body)) {
        echo 'SUCCESS!  PHP successfully delivered email to your MTA.  If you don\'t see the email in your inbox in a few minutes, there is a problem with your MTA.';
} else {
        echo 'ERROR!  PHP could not deliver email to your MTA.  Check that your PHP settings are correct for your MTA and your MTA will deliver email.';
}

Be sure to replace „your_email@your_host.com“ with your actual email address. Take care to keep quotes around it! When you access this page through your web browser, it will attempt to send a test email. This test will let you know that PHP and your MTA are correctly configured. If it fails–either you get an error or you never receive the email–you will need to do more investigating and possibly contact your service provider.

Fully configuring an MTA and PHP’s email functionality is beyond the scope of this FAQ and you should search the Internet for more resources on this. Some basic information on php parameters can be found on PHP’s site

Server logs¶

Most likely you are using Apache as your web server. Warnings and errors are written to a log by the web server and can be useful for debugging problems. You will commonly see two types of log files: access logs and error logs. Information from PHP and Elgg is written to the server error log.

Linux – The error log is probably in /var/log/httpd or /var/log/apache2.

Windows - It is probably inside your Apache directory.

Mac OS - The error log is probably in /var/log/apache2/error_log

If you are using shared hosting without ssh access, your hosting provider may provide a mechanism for obtaining access to your server logs. You will need to ask them about this.

How does registration work?¶

With a default setup, this is how registration works:

User fills out registration form and submits it
User account is created and disabled until validated
Email is sent to user with a link to validate the account
When a user clicks on the link, the account is validated
The user can now log in

Failures during this process include the user entering an incorrect email address, the validation email being marked as spam, or a user never bothering to validate the account.

User validation¶

By default, all users who self-register must validate their accounts through email. If a user has problems validating an account, you can validate users manually by going to Administration -> Users -> Unvalidated.

You can remove this requirement by deactivating the User Validation by Email plugin.

Bemerkung

Removing validation has some consequences: There is no way to know that a user registered with a working email address, and it may leave you system open to spammers.

Manually add user¶

To manually add a user, under the Administer controls go to Users. There you will see a link title „Add new User“. After you fill out the information and submit the form, the new user will receive an email with username and password and a reminder to change the password.

Bemerkung

Elgg does not force the user to change the password.

I’m making or just installed a new theme, but graphics or other elements aren’t working¶

Make sure the theme is at the bottom of the plugin list.

Clear your browser cache and reload the page. To lighten the load on the server, Elgg instructs the browser to rarely load the CSS file. A new theme will completely change the CSS file and a refresh should cause the browser to request the CSS file again.

If you’re building or modifying a theme, make sure you have disabled the simple and system caches. This can be done by enabling the Developer Tools plugin, then browsing to Administration -> Develop -> Settings. Once you’re satisfied with the changes, enable the caches or performance will suffer.

Changing profile fields¶

Within the Administration settings of Elgg is a page for replacing the default profile fields. Elgg by default gives the administrator two choices:

Use the default profile fields
Replace the default with a set of custom profile fields

You cannot add new profile fields to the default ones. Adding a new profile field through the replace profile fields option clears the default ones. Before letting in users, it is best to determine what profile fields you want, what field types they should be, and the order they should appear. You cannot change the field type or order or delete fields after they have been created without wiping the entire profile blank.

More flexibility can be gained through plugins. There is at least two plugins on the community site that enable you to have more control over profile fields. The Profile Manager plugin has become quite popular in the Elgg community. It lets you add new profile fields whenever you want, change the order, group profile fields, and add them to registration.

Changing registration¶

The registration process can be changed through a plugin. Everything about registration can be changed: the look and feel, different registration fields, additional validation of the fields, additional steps and so on. These types of changes require some basic knowledge of HTML, CSS, PHP.

Another option is to use the Profile Manager plugin that lets you add fields to both user profiles and the registration form.

Create the plugin skeleton: Plugin skeleton
Changing registration display: Override the account/forms/register view
Changing the registration action handler: You can write your own action to create the user’s account

How do I change PHP settings using .htaccess?¶

You may want to change php settings in your .htaccess file. This is especially true if your hosting provider does not give you access to the server’s php.ini file. The variables could be related to file upload size limits, security, session length, or any number of other php attributes. For examples of how to do this, see the PHP documentation on this.

HTTPS login turned on accidently¶

If you have turned on HTTPS login but do not have SSL configured, you are now locked out of your Elgg install. To turn off this configuration parameter, you will need to edit your database. Use a tool like phpMyAdmin to view your database. Select the config table and delete the row that has the name https_login.

Using a test site¶

It is recommended to always try out new releases or new plugins on a test site before running them on a production site (a site with actual users). The easiest way to do this is to maintain a separate install of Elgg with dummy accounts. When testing changes it is important to use dummy accounts that are not admins to test what your users will see.

A more realistic test is to mirror the content from your production site to your test site. Following the instructions for duplicating a site. Then make sure you prevent emails from being sent to your users. You could write a small plugin that redirects all email to your own account (be aware of plugins that include their own custom email sending code so you’ll have to modify those plugins). After this is done you can view all of the content to make sure the upgrade or new plugin is functioning as desired and is not breaking anything. If this process sounds overwhelming, please stick with running a simple test site.

500 - Internal Server Error¶

What is it?¶

A 500 - Internal Server Error means the web server experienced a problem serving a request.

Siehe auch

The Wikipedia page on HTTP status codes

Possible causes¶

Web server configuration: The most common cause for this is an incorrectly configured server. If you edited the .htaccess file and added something incorrect, Apache will send a 500 error.
Permissions on files: It could also be a permissions problem on a file. Apache needs to be able to read Elgg’s files. Using permissions 755 on directories and 644 on files will allow Apache to read the files.

When I upload a photo or change my profile picture I get a white screen¶

Most likely you don’t have the PHP GD library installed or configured properly. You may need assistance from the administrator of your server.

CSS is missing¶

Wrong URL¶

Sometimes people install Elgg so that the base URL is localhost and then try to view the site using a hostname. In this case, the browser won’t be able to load the CSS file. Try viewing the source of the web page and copying the link for the CSS file. Paste that into your browser. If you get a 404 error, it is likely this is your problem. You will need to change the base URL of your site.

Syntax error¶

Elgg stores its CSS as PHP code to provide flexibility and power. If there is a syntax error, the CSS file served to the browser may be blank. Disabling non-bundled plugins is the recommended first step.

Rewrite rules errors¶

A bad .htaccess file could also result in a 404 error when requesting the CSS file. This could happen when doing an upgrade and forgetting to also upgrade .htaccess.

Should I edit the database manually?¶

Warnung

No, you should never manually edit the database!

Will editing the database manually break my site?¶

Yes.

Can I add extra fields to tables in the database?¶

(AKA: I don’t understand the Elgg data model so I’m going to add columns. Will you help?)

No, this is a bad idea. Learn the data model and you will see that unless it’s a very specific and highly customized installation, you can do everything you need within Elgg’s current data model.

I want to remove users. Can’t I just delete them from the elgg_entities table?¶

No, it will corrupt your database. Delete them through the site.

I want to remove spam. Can’t I just search and delete it from the elgg_entities table?¶

No, it will corrupt your database. Delete it through the site.

Someone on the community site told me to edit the database manually. Should I?¶

Who was it? Is it someone experienced with Elgg, like one of the core developers or a well-known plugin author? Did he or she give you clear and specific instructions on what to edit? If you don’t know who it is, or if you can’t understand or aren’t comfortable following the instructions, do not edit the database manually.

I know PHP and MySQL and have a legitimate reason to edit the database. Is it okay to manually edit the database?¶

Make sure you understand Elgg’s data model and schema first. Make a backup, edit carefully, then test copiously.

Internet Explorer (IE) login problem¶

Canonical URL¶

IE does not like working with sites that use both http://example.org and http://www.example.org. It stores multiple cookies and this causes problems. Best to only use one base URL. For details on how to do this see Login token mismatch error.

Chrome Frame¶

Using the chrome frame within IE can break the login process.

Emails don’t support non-Latin characters¶

In order to support non-Latin characters, (such as Cyrillic or Chinese) Elgg requires multibyte string support to be compiled into PHP.

On many installs (e.g. Debian & Ubuntu) this is turned on by default. If it is not, you need to turn it on (or recompile PHP to include it). To check whether your server supports multibyte strings, check phpinfo.

Session length¶

Session length is controlled by your php configuration. You will first need to locate your php.ini file. In that file will be several session variables. A complete list and what they do can be found in the php manual.

File is missing an owner¶

There are three causes for this error. You could have an entity in your database that has an owner_guid of 0. This should be extremely rare and may only occur if your database/server crashes during a write operation.

The second cause would be an entity where the owner no longer exists. This could occur if a plugin is turned off that was involved in the creation of the entity and then the owner is deleted but the delete operation failed (because the plugin is turned off). If you can figure out entity is causing this, look in your entities table and change the owner_guid to your own and then you can delete the entity through Elgg.

Warnung

Reed the section „Should I edit the database manually?“. Be very carefull when editing the database directly. It can break your site. Always make a backup before doing this.

Fixes¶

Database Validator plugin will check your database for these causes and provide an option to fix them. Be sure to backup the database before you try the fix option.

No images¶

If profile images, group images, or other files have stopped working on your site it is likely due to a misconfiguration, especially if you have migrated to a new server.

These are the most common misconfigurations that cause images and other files to stop working.

Wrong path for data directory¶

Make sure the data directory’s path is correct in the Site Administration admin area. It should have a trailing slash.

Wrong permissions on the data directory¶

Check the permissions for the data directory. The data directory should be readable and writeable by the web server user.

Migrated installation with new data directory location¶

If you migrated an installation and need to change your data directory path, be sure to update the SQL for the filestore location as documented in the Duplicate Installation instructions.

Deprecation warnings¶

If you are seeing many deprecation warnings that say things like

Deprecated in 1.7: extend_view() was deprecated by elgg_extend_view()!

then you are using a plugin that was written for an older version of Elgg. This means the plugin is using functions that are scheduled to be removed in a future version of Elgg. You can ask the plugin developer if the plugin will be updated or you can update the plugin yourself. If neither of those are likely to happen, you should not use that plugin.

Javascript not working¶

If the user hover menu stops working or you cannot dismiss system messages, that means JavaScript is broken on your site. This usually due to a plugin having bad JavaScript code. You should find the plugin causing the problem and disable it. You can do this be disabling non-bundled plugins one at a time until the problem goes away. Another approach is disabling all non-bundled plugins and then enabling them one by one until the problem occurs again.

Most web browsers will give you a hint as to what is breaking the JavaScript code. They often have a console for JavaScript errors or an advanced mode for displaying errors. Once you see the error message, you may have an easier time locating the problem.

Security¶

Is upgrade.php a security concern?¶

Upgrade.php is a file used to run code and database upgrades. It is in the root of the directory and doesn’t require a logged in account to access. On a fully upgraded site, running the file will only reset the caches and exit, so this is not a security concern.

If you are still concerned, you can either delete, move, or change permissions on the file until you need to upgrade.

Should I delete install.php?¶

This file is used to install Elgg and doesn’t need to be deleted. The file checks if Elgg is already installed and forwards the user to the front page if it is.

Filtering¶

Filtering is used in Elgg to make XSS attacks more difficult. The purpose of the filtering is to remove Javascript and other dangerous input from users.

Filtering is performed through the function filter_tags(). This function takes in a string and returns a filtered string. It triggers a validate, input plugin hook. By default Elgg comes with the htmLawed filtering code as a plugin. Developers can drop in any additional or replacement filtering code as a plugin.

The filter_tags() function is called on any user input as long as the input is obtained through a call to get_input(). If for some reason a developer did not want to perform the default filtering on some user input, the get_input() function has a parameter for turning off filtering.

Development¶

What should I use to edit php code?¶

There are two main options: text editor or integrated development environment (IDE).

Text Editor¶

If you are new to software development or do not have much experience with IDEs, using a text editor will get you up and running the quickest. At a minimum, you will want one that does syntax highlighting to make the code easier to read. If you think you might submit patches to the bug tracker, you will want to make sure that your text editor does not change line endings. If you are using Windows, Notepad++ is a good choice. If you are on a Mac, TextWrangler is a popular choice. You could also give TextMate a try.

Integrated Development Environment¶

An IDE does just what its name implies: it includes a set of tools that you would normally use separately. Most IDEs will include source code control which will allow you to directly commit and update your code from your cvs repository. It may have an FTP client built into it to make the transfer of files to a remote server easier. It will have syntax checking to catch errors before you try to execute the code on a server.

The two most popular free IDEs for PHP developers are Eclipse and NetBeans. Eclipse has two different plugins for working with PHP code: PDT and PHPEclipse.

I don’t like the wording of something in Elgg. How do I change it?¶

The best way to do this is with a plugin.

Create the plugin skeleton¶

Plugin skeleton

Locate the string that you want to change¶

All the strings that a user sees should be in the /languages directory or in a plugin’s languages directory (/mod/<plugin name>/languages). This is done so that it is easy to change what language Elgg uses. For more information on this see the developer documentation on Internationalization .

To find the string use grep or a text editor that provides searching through files to locate the string. (A good text editor for Windows is Notepad++ ) Let’s say we want to change the string „Add friend“ to „Make a new friend“. The grep command to find this string would be grep -r "Add friend" *. Using Notepad++ , you would use the „Find in files“ command. You would search for the string, set the filter to *.php, set the directory to the base directory of Elgg, and make sure it searches all subdirectories. You might want to set it to be case sensitive also.

You should locate the string „Add friend“ in /languages/en.php. You should see something like this in the file:

'friend:add' => "Add friend",

This means every time Elgg sees friend:add it replaces it with „Add friend“. We want to change the definition of friend:add.

Override the string¶

To override this definition, we will add a languages file to the plugin that we built in the first step.

Create a new directory: /mod/<your plugin name>/languages
Create a file in that directory called en.php
Add these lines to that file

<?php

return array(
   'friend:add' => 'Make a new friend',
);

Make sure that you do not have any spaces or newlines before the <?php.

You’re done now and should be able to enable the plugin and see the change. If you are override the language of a plugin, make sure your plugin is loaded after the one you are trying to modify. The loading order is determined in the Tools Administration page of the admin section. As you find more things that you’d like to change, you can keep adding them to this plugin.

How do I find the code that does x?¶

The best way to find the code that does something that you would like to change is to use grep or a similar search tool. If you do not have grep as a part of your operating system, you will want to install a grep tool or use a text-editor/IDE that has good searching in files. Notepad++ is a good choice for Windows users. Eclipse with PHP and NetBeans are good choices for any platform.

String Example¶

Let’s say that you want to find where the Log In box code is located. A string from the Log In box that should be fairly unique is Remember me. Grep for that string. You will find that it is only used in the en.php file in the /languages directory. There it is used to define the Internationalization string user:persistent. Grep for that string now. You will find it in two places: the same en.php language file and in /views/default/forms/login.php. The latter defines the html code that makes up the Log In box.

Action Example¶

Let’s say that you want to find the code that is run when a user clicks on the Save button when arranging widgets on a profile page. View the Profile page for a test user. Use Firebug to drill down through the html of the page until you come to the action of the edit widgets form. You’ll see the url from the base is action/widgets/move.

Grep on widgets/move and two files are returned. One is the JavaScript code for the widgets : /js/lib/ui.widgets.js. The other one, /engine/lib/widgets.php, is where the action is registered using elgg_register_action('widgets/reorder'). You may not be familiar with that function in which case, you should look it up at the API reference. Do a search on the function and it returns the documentation on the function. This tells you that the action is in the default location since a file location was not specified. The default location for actions is /actions so you will find the file at /actions/widgets/move.php.

Debug mode¶

During the installation process you might have noticed a checkbox that controlled whether debug mode was turned on or off. This setting can also be changed on the Site Administration page. Debug mode writes a lot of extra data to your php log. For example, when running in this mode every query to the database is written to your logs. It may be useful for debugging a problem though it can produce an overwhelming amount of data that may not be related to the problem at all. You may want to experiment with this mode to understand what it does, but make sure you run Elgg in normal mode on a production server.

Warnung

Because of the amount of data being logged, don’t enable this on a production server as it can fill up the log files really quick.

What goes into the log in debug mode?¶

All database queries
Database query profiling
Page generation time
Number of queries per page
List of plugin language files
Additional errors/warnings compared to normal mode (it’s very rare for these types of errors to be related to any problem that you might be having)

What does the data look like?¶

[07-Mar-2009 14:27:20] Query cache invalidated
[07-Mar-2009 14:27:20] ** GUID:1 loaded from DB
[07-Mar-2009 14:27:20] SELECT * from elggentities where guid=1 and ( (1 = 1)  and enabled='yes') results cached
[07-Mar-2009 14:27:20] SELECT guid from elggsites_entity where guid = 1 results cached
[07-Mar-2009 14:27:20] Query cache invalidated
[07-Mar-2009 14:27:20] ** GUID:1 loaded from DB
[07-Mar-2009 14:27:20] SELECT * from elggentities where guid=1 and ( (1 = 1)  and enabled='yes') results cached
[07-Mar-2009 14:27:20] ** GUID:1 loaded from DB
[07-Mar-2009 14:27:20] SELECT * from elggentities where guid=1 and ( (1 = 1)  and enabled='yes') results returned from cache
[07-Mar-2009 14:27:20] ** Sub part of GUID:1 loaded from DB
[07-Mar-2009 14:27:20] SELECT * from elggsites_entity where guid=1 results cached
[07-Mar-2009 14:27:20] Query cache invalidated
[07-Mar-2009 14:27:20] DEBUG: 2009-03-07 14:27:20 (MST): "Undefined index:  user" in file /var/www/elgg/engine/lib/elgglib.php (line 62)
[07-Mar-2009 14:27:20] DEBUG: 2009-03-07 14:27:20 (MST): "Undefined index:  pass" in file /var/www/elgg/engine/lib/elgglib.php (line 62)
[07-Mar-2009 14:27:20] ***************** DB PROFILING ********************
[07-Mar-2009 14:27:20] 1 times: 'SELECT * from elggentities where guid=1 and (  (access_id in (2) or (owner_guid = -1) or (access_id = 0 and owner_guid = -1)) and enabled='yes')'
...
[07-Mar-2009 14:27:20] 2 times: 'update elggmetadata set access_id = 2 where entity_guid = 1'
[07-Mar-2009 14:27:20] 1 times: 'UPDATE elggentities set owner_guid='0', access_id='2', container_guid='0', time_updated='1236461868' WHERE guid=1'
[07-Mar-2009 14:27:20] 1 times: 'SELECT guid from elggsites_entity where guid = 1'
[07-Mar-2009 14:27:20] 1 times: 'UPDATE elggsites_entity set name='3124/944', description='', url='http://example.org/' where guid=1'
[07-Mar-2009 14:27:20] 1 times: 'UPDATE elggusers_entity set prev_last_action = last_action, last_action = 1236461868 where guid = 2'
[07-Mar-2009 14:27:20] DB Queries for this page: 56
[07-Mar-2009 14:27:20] ***************************************************
[07-Mar-2009 14:27:20] Page /action/admin/site/update_basic generated in 0.36997294426 seconds

What events are triggered on every page load?¶

There are 4 Elgg events that are triggered on every page load:

plugins_boot, system
init, system
ready, system
shutdown, system

The first three are triggered in Elgg\Application::bootCore. shutdown, system is triggered in \Elgg\Application\ShutdownHandler after the response has been sent to the client. They are all documented.

There are other events triggered by Elgg occasionally (such as when a user logs in).

Copy a plugin¶

There are many questions asked about how to copy a plugin. Let’s say you want to copy the blog plugin in order to run one plugin called blog and another called poetry. This is not difficult but it does require a lot of work. You would need to

change the directory name
change the names of every function (having two functions causes PHP to crash)
change the name of every view (so as not to override the views on the original plugin)
change any data model subtypes
change the language file
change anything else that was specific to the original plugin

Bemerkung

If you are trying to clone the groups plugin, you will have the additional difficulty that the group plugin does not set a subtype.

General ¶

Siehe auch

Getting Help

„Plugin cannot start and has been deactivated“ or „This plugin is invalid“¶

This error is usually accompanied by more details explaining why the plugin is invalid. This is usually caused by an incorrectly installed plugin.

If you are installing a plugin called „test“, there will be a test directory under mod. In that test directory there needs to be a manifest.xml file /mod/test/manifest.xml.

If this file does not exist, it could be caused by:

installing a plugin to the wrong directory
creating a directory under /mod that does not contain a plugin
a bad ftp transfer
unzipping a plugin into an extra directory (myplugin.zip unzips to myplugin/myplugin)

If you are on a Unix-based host and the files exist in the correct directory, check the permissions. Elgg must have read access to the files and read + execute access on the directories.

White Page (WSOD)¶

A blank, white page (often called a „white screen of death“) means there is a PHP syntax error. There are a few possible causes of this:

corrupted file - try transfering the code again to your server
a call to a php module that was not loaded - this can happen after you install a plugin that requires a specific module.
bad plugin - not all plugins have been written to the same quality so you should be careful which ones you install.

To find where the error is occurring, change the .htaccess file to display errors to the browser. Set display_errors to 1 and load the same page again. You should see a PHP error in your browser. Change the setting back once you’ve resolved the problem.

Bemerkung

If you are using the Developer’s Tools plugin, go to its settings page and make sure you have „Display fatal PHP errors“ enabled.

If the white screen is due to a bad plugin, remove the latest plugins that you have installed by deleting their directories and then reload the page.

Bemerkung

You can temporarily disable all plugins by creating an empty file at mod/disabled. You can then disable the offending module via the administrator tools panel.

If you are getting a WSOD when performing an action, like logging in or posting a blog, but there are no error messages, it’s most likely caused by non-printable characters in plugin code. Check the plugin for white spaces/new lines characters after finishing php tag (?>) and remove them.

Page not found ¶

If you have recently installed your Elgg site, the most likely cause for a page not found error is that mod_rewrite is not setup correctly on your server. There is information in the Install Troubleshooting page on fixing this. The second most likely cause is that your site url in your database is incorrect.

If you’ve been running your site for a while and suddenly start getting page not found errors, you need to ask yourself what has changed. Have you added any plugins? Did you change your server configuration?

To debug a page not found error:

Confirm that the link leading to the missing page is correct. If not, how is that link being generated?
Confirm that the .htaccess rewrite rules are being picked up.

Login token mismatch ¶

If you have to log in twice to your site and the error message after the first attempt says there was a token mismatch error, the URL in Elgg’s settings does not match the URL used to access it. The most common cause for this is adding or removing the „www“ when accessing the site. For example, www.elgg.org vs elgg.org. This causes a problem with session handling because of the way that web browsers save cookies.

To fix this, you can add rewrite rules. To redirect from www.elgg.org to elgg.org in Apache, the rules might look like:

RewriteCond %{HTTP_HOST} .
RewriteCond %{HTTP_HOST} !^elgg\.org
RewriteRule (.*) http://elgg.org/$1 [R=301,L]

Redirecting from non-www to www could look like this:

RewriteCond %{HTTP_HOST} ^elgg\.org
RewriteRule ^(.*)$ http://www.elgg.org/$1 [R=301,L]

If you don’t know how to configure rewrite rules, ask your host for more information.

Form is missing token or ts fields ¶

All Elgg actions require a security token, and this error occurs when that token is missing. This is either a problem with your server configuration or with a 3rd party plugin.

If you experience this on a new installation, make sure that your server is properly configured and your rewrite rules are correct. If you experience this on an upgrade, make sure you have updated your rewrite rules either in .htaccess (Apache) or in the server configuration.

If you are experiencing this, disable all 3rd party plugins and try again. Very old plugins for Elgg don’t use security tokens. If the problem goes away when plugins are disabled, it’s due to a plugin that should be updated by its author.

Maintenance mode ¶

To take your site temporarily offline, go to Administration -> Utilities -> Maintenance Mode. Complete the form and hit save to disable your site for everyone except admin users.

Missing email ¶

If your users are reporting that validation emails are not showing up, have them check their spam folder. It is possible that the emails coming from your server are being marked as spam. This depends on many factors such as whether your hosting provider has a problem with spammers, how your PHP mail configuration is set up, what mail transport agent your server is using, or your host limiting the number of email that you can send in an hour.

If no one gets email at all, it is quite likely your server is not configured properly for email. Your server needs a program to send email (called a Mail Transfer Agent - MTA) and PHP must be configured to use the MTA.

To quickly check if PHP and an MTA are correctly configured, create a file on your server with the following content:

<?php
$address = "your_email@your_host.com";

$subject = 'Test email.';

$body = 'If you can read this, your email is working.';

echo "Attempting to email $address...<br />";

if (mail($address, $subject, $body)) {
        echo 'SUCCESS!  PHP successfully delivered email to your MTA.  If you don\'t see the email in your inbox in a few minutes, there is a problem with your MTA.';
} else {
        echo 'ERROR!  PHP could not deliver email to your MTA.  Check that your PHP settings are correct for your MTA and your MTA will deliver email.';
}

Be sure to replace „your_email@your_host.com“ with your actual email address. Take care to keep quotes around it! When you access this page through your web browser, it will attempt to send a test email. This test will let you know that PHP and your MTA are correctly configured. If it fails–either you get an error or you never receive the email–you will need to do more investigating and possibly contact your service provider.

Fully configuring an MTA and PHP’s email functionality is beyond the scope of this FAQ and you should search the Internet for more resources on this. Some basic information on php parameters can be found on PHP’s site

Server logs ¶

Most likely you are using Apache as your web server. Warnings and errors are written to a log by the web server and can be useful for debugging problems. You will commonly see two types of log files: access logs and error logs. Information from PHP and Elgg is written to the server error log.

Linux – The error log is probably in /var/log/httpd or /var/log/apache2.

Windows - It is probably inside your Apache directory.

Mac OS - The error log is probably in /var/log/apache2/error_log

If you are using shared hosting without ssh access, your hosting provider may provide a mechanism for obtaining access to your server logs. You will need to ask them about this.

How does registration work?¶

With a default setup, this is how registration works:

User fills out registration form and submits it
User account is created and disabled until validated
Email is sent to user with a link to validate the account
When a user clicks on the link, the account is validated
The user can now log in

Failures during this process include the user entering an incorrect email address, the validation email being marked as spam, or a user never bothering to validate the account.

User validation ¶

By default, all users who self-register must validate their accounts through email. If a user has problems validating an account, you can validate users manually by going to Administration -> Users -> Unvalidated.

You can remove this requirement by deactivating the User Validation by Email plugin.

Bemerkung

Removing validation has some consequences: There is no way to know that a user registered with a working email address, and it may leave you system open to spammers.

Manually add user ¶

To manually add a user, under the Administer controls go to Users. There you will see a link title „Add new User“. After you fill out the information and submit the form, the new user will receive an email with username and password and a reminder to change the password.

Bemerkung

Elgg does not force the user to change the password.

I’m making or just installed a new theme, but graphics or other elements aren’t working ¶

Make sure the theme is at the bottom of the plugin list.

Clear your browser cache and reload the page. To lighten the load on the server, Elgg instructs the browser to rarely load the CSS file. A new theme will completely change the CSS file and a refresh should cause the browser to request the CSS file again.

If you’re building or modifying a theme, make sure you have disabled the simple and system caches. This can be done by enabling the Developer Tools plugin, then browsing to Administration -> Develop -> Settings. Once you’re satisfied with the changes, enable the caches or performance will suffer.

Changing profile fields ¶

Within the Administration settings of Elgg is a page for replacing the default profile fields. Elgg by default gives the administrator two choices:

Use the default profile fields
Replace the default with a set of custom profile fields

You cannot add new profile fields to the default ones. Adding a new profile field through the replace profile fields option clears the default ones. Before letting in users, it is best to determine what profile fields you want, what field types they should be, and the order they should appear. You cannot change the field type or order or delete fields after they have been created without wiping the entire profile blank.

More flexibility can be gained through plugins. There is at least two plugins on the community site that enable you to have more control over profile fields. The Profile Manager plugin has become quite popular in the Elgg community. It lets you add new profile fields whenever you want, change the order, group profile fields, and add them to registration.

Changing registration ¶

The registration process can be changed through a plugin. Everything about registration can be changed: the look and feel, different registration fields, additional validation of the fields, additional steps and so on. These types of changes require some basic knowledge of HTML, CSS, PHP.

Another option is to use the Profile Manager plugin that lets you add fields to both user profiles and the registration form.

Create the plugin skeleton: Plugin skeleton
Changing registration display: Override the account/forms/register view
Changing the registration action handler: You can write your own action to create the user’s account

How do I change PHP settings using .htaccess?¶

You may want to change php settings in your .htaccess file. This is especially true if your hosting provider does not give you access to the server’s php.ini file. The variables could be related to file upload size limits, security, session length, or any number of other php attributes. For examples of how to do this, see the PHP documentation on this.

HTTPS login turned on accidently ¶

If you have turned on HTTPS login but do not have SSL configured, you are now locked out of your Elgg install. To turn off this configuration parameter, you will need to edit your database. Use a tool like phpMyAdmin to view your database. Select the config table and delete the row that has the name https_login.

Using a test site ¶

It is recommended to always try out new releases or new plugins on a test site before running them on a production site (a site with actual users). The easiest way to do this is to maintain a separate install of Elgg with dummy accounts. When testing changes it is important to use dummy accounts that are not admins to test what your users will see.

A more realistic test is to mirror the content from your production site to your test site. Following the instructions for duplicating a site. Then make sure you prevent emails from being sent to your users. You could write a small plugin that redirects all email to your own account (be aware of plugins that include their own custom email sending code so you’ll have to modify those plugins). After this is done you can view all of the content to make sure the upgrade or new plugin is functioning as desired and is not breaking anything. If this process sounds overwhelming, please stick with running a simple test site.

500 - Internal Server Error ¶

What is it?¶

A 500 - Internal Server Error means the web server experienced a problem serving a request.

Siehe auch

The Wikipedia page on HTTP status codes

Possible causes¶

Web server configuration: The most common cause for this is an incorrectly configured server. If you edited the .htaccess file and added something incorrect, Apache will send a 500 error.
Permissions on files: It could also be a permissions problem on a file. Apache needs to be able to read Elgg’s files. Using permissions 755 on directories and 644 on files will allow Apache to read the files.

When I upload a photo or change my profile picture I get a white screen ¶

Most likely you don’t have the PHP GD library installed or configured properly. You may need assistance from the administrator of your server.

CSS is missing ¶