Plugins

Plugins must provide a composer.json file in the plugin root in order to be recognized by Elgg.

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:

  • plugin - defines plugin information and dependencies
  • 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()
  • cli_commands - an array of Elgg/Cli/Command classes to extend the feature of elgg-cli
  • view_extensions - eliminates the need for calling elgg_extend_view() or elgg_unextend_view()
  • theme - an array of theme variables
  • group_tools - an array of available group tool options
  • view_options - an array of views with extra options
  • notifications - an array of notification events
return [
        'plugin' => [
                'name' => 'Plugin Name', // readable plugin name
                'activate_on_install' => true, // only used on a fresh install
                'version' => '1.3.1', // version of the plugin
                'dependencies' => [
                        // optional list op plugin dependencies
                        'blog' => [],
                        'activity' => [
                                'position' => 'after',
                                'must_be_active' => false,
                        ],
                        'file' => [
                                'position' => 'before',
                                'version' => '>2', // composer notation of required version constraint
                        ],
                ],
        ],

        // 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,

                        'capabilities' => [
                                // Register this subtype for search
                                'searchable' => true,

                                'likable' => 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', 'logged_out', '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,
                                ],
                        ],
                ],
                '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' => [
                                'Elgg\SystemLog\Logger::log' => ['unregister' => true],
                        ],
                ],
        ],

        'cli_commands' => [
                \My\Plugin\CliCommand::class,
                '\My\Plugin\OtherCliCommand',
        ],

        'view_extensions' => [
                'elgg.js' => [
                        'bookmarks.js' => [],
                ],
                'page/components/list' => [
                        'list/extension' => [
                                'priority' => 600,
                        ],
                ],
                'forms/usersettings/save' => [
                        'core/settings/account/password' => [
                                'unextend' => true,
                        ],
                ],
        ],

        'theme' => [
                'body-background-color' => '#000',
        ],

        'group_tools' => [
                'activity' => [], // just use default behaviour
                'blog' => [
                        'default_on' => false,
                ],
                'forum' => [
                        'unregister' => true, // unregisters the group tool option
                ],
        ],

        'view_options' => [
                'likes/popup' => [
                        'ajax' => true, // registers the view available via ajax
                ],
                'likes/popup' => [
                        'ajax' => false, // unregisters the view available via ajax
                ],
                'manifest.json' => [
                        'simplecache' => true, // register view as usable in the simplecache
                ],
        ],
        'notifications' => [
                'object' => [
                        'blog' => [
                                'publish' => true, // registers the event to be notified
                        ],
                        'thewire' => [
                                'create' => false, // unregisters the event to be notified
                        ],
                        'page' => [
                                'create' => MyPluginPageCreateEventHandler::class, // a custom event handler, needs to be an extension of a NotificationEventHandler
                        ],
                ],
        ],
];

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

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.

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