List of plugin hooks in core

System hooks

email, system

Triggered when sending email. $params contains:

  • to
  • from
  • subject
  • body
  • headers
  • params
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.

search_types, get_types

cron, <period>
Triggered by cron for each period.
validate, input
Filter GET and POST input. This is used by get_input() to sanitize user input.
geocode, location
Deprecated as of 1.9.
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.
output:before, layout
In elgg_view_layout(), filters $params before it’s passed to the layout view.
output:after, layout
In elgg_view_layout(), filters the return value of the layout view.
output, ajax
Triggered in the ajax forward hook that is called for ajax requests. Allows plugins to alter the output returned, including the forward URL, system messages, and errors.
parameters, menu:<menu_name>
Triggered by elgg_view_menu(). Used to change menu variables (like sort order) before it is generated.
register, menu:<menu_name>
Triggered by elgg_view_menu(). Used to add dynamic menu items.
prepare, menu:<menu_name>
Trigger by elgg_view_menu(). Used to sort, add, remove, and modify menu items.
creating, river
Triggered before a river item is created. Return false to prevent river item from being created.
simplecache:generate, <view>
Triggered when generating the cached content of a view.
get, subscriptions
Filter notification subscriptions for users for the Elgg_Notifications_Event $params['event']. Return an array like:
array(
        <user guid> => array('subscription', 'types'),
        <user_guid2> => array('email', 'sms', 'ajax')
);
prepare, breadcrumbs
In elgg_get_breadcrumbs(), this filters the registered breadcrumbs before returning them, allowing a plugin to alter breadcrumb strategy site-wide.

add, river

User hooks

usersettings:save, user
Triggered in the aggregate action to save user settings. Return false prevent sticky forms from being cleared.
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.
registeruser:validate:password, all
Return boolean for if the string in $params['password'] is valid for a password.
registeruser:validate:email, all
Return boolean for if the string in $params['email'] is valid for an email address.
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.
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'].

Action hooks

action, <action>
Triggered before executing action scripts. Return false to abort action.
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.

Permission hooks

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'].
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, 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>
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.

Note

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.

Warning

This is functions differently than the permissions_check:metadata hook by passing the annotation name instead of the metadata object.

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.
access:collections:read, user

Filters an array of access IDs that the user $params['user_id'] can see.

Warning

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.

Warning

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: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 the SQL clauses used in _elgg_get_access_where_sql().

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
shell, page
In elgg_view_page(), filters the page shell name
head, page
In elgg_view_page(), filters $vars['head']

Files

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.

Other

config, comments_per_page
Filters the number of comments displayed per page. Default is 25.
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.
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_config('icon_sizes');
        $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: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.
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
)
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.
public_pages, walled_garden
Filter the URLs that are can be seen by logged out users if Walled Garden is enabled. $value is an array of regex strings that will allow access if matched.
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

HTMLawed

allowed_styles, htmlawed
Filter the HTMLawed allowed style array.
config, htmlawed
Filter the HTMLawed config array.

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.

Twitter API

authorize, twitter_api
Triggered when a user is authorizes Twitter for a login. $params['token'] contains the Twitter authorization token.

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.