List of events in core

For more information on how events work visit Events.

Note

Some events are marked with this means those events also have a :before and :after event Also see Event sequence

Some events are marked with this means those events allow altering the output of an event

System events

activate, plugin

Return false to prevent activation of the plugin.

cache:clear, system

Clear 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.

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.

cache:invalidate, system

Invalidate internal and external caches.

cache:purge, system

Purge internal and external caches. This is meant to remove old/stale content from the caches.

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.

cron, <period>

Triggered by cron for each period.

The $params array will contain:

• time - the timestamp of when the cron command was started

• dt - the \DateTime object of when the cron command was started

• logger - instance of \Elgg\Logger\Cron to log any information to the cron log

cron:intervals, system

Allow the configuration of custom cron intervals

deactivate, plugin

Return false to prevent deactivation of the plugin.

diagnostics:report, system

Filter the output for the diagnostics report download.

elgg.data, page

Filters uncached, page-specific configuration data to pass to the client. More info

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'].

gc, system

Allows plugins to run garbage collection for $params['period'].

generate, password

Allows plugins to generate new random cleartext passwords.

init:cookie, <name>

Return false to override setting a cookie.

init, system

Plugins tend to use this event for initialization (extending views, registering callbacks, etc.)

languages, translations

Allows plugins to add/remove languages from the configurable languages in the system.

log, systemlog

Called for all triggered events by system_log plugin. Used internally by Elgg\SystemLog\Logger::log() to populate the system_log table.

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 event must return an absolute URL of the login page.

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\Page\SetXFrameOptionsHeaderHandler::class from this event.

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()

plugins_load, system

Triggered before the plugins are loaded. Rarely used. init, system is used instead. Can be used to load additional libraries.

plugins_boot, system

Triggered just after the plugins are loaded. Rarely used. init, system is used instead.

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

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 event 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.

prepare, menu:<menu_name>:<type>:<subtype>

More granular version of the menu event triggered before the prepare, menu:<menu_name> event.

Only applied if menu params contain - params[‘entity’] with an \ElggEntity (<type> is \ElggEntity::type and <subtype> is \ElggEntity::subtype) or - params[‘annotation’] with an \ElggAnnotation (<type> is \ElggAnnotation::getType() and <subtype> is \ElggAnnotation::getSubtype()) or - params[‘relationship’] with an \ElggRelationship (<type> is \ElggRelationship::getType() and <subtype> is \ElggRelationship::getSubtype())

ready, system

Triggered after the init, system event. All plugins are fully loaded and the engine is ready to serve pages.

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.

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> event.

The return value is an instance of \Elgg\Menu\MenuItems containing \ElggMenuItem objects.

Event handlers can add/remove items to the collection using the collection API, as well as array access operations.

register, menu:<menu_name>:<type>:<subtype>

More granular version of the menu event triggered before the register, menu:<menu_name> event.

Only applied if menu params contain - params[‘entity’] with an \ElggEntity (<type> is \ElggEntity::type and <subtype> is \ElggEntity::subtype) or - params[‘annotation’] with an \ElggAnnotation (<type> is \ElggAnnotation::getType() and <subtype> is \ElggAnnotation::getSubtype()) or - params[‘relationship’] with an \ElggRelationship (<type> is \ElggRelationship::getType() and <subtype> is \ElggRelationship::getSubtype())

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> event.

If filter_id is filter (the default) then the all, mine and friends tabs will be generated base on some provided information or be tried for routes similar to the current route.

• params[‘all_link’] will be used for the all tab

• params[‘mine_link’] will be used for the mine tab

• params[‘friends_link’] will be used for the friend tab

If the above are not provided than a route will be tried based on params['entity_type'] and params['entity_subtype']. If not provided entity_type and entity_subtype will be based on route detection of the current route. For example if the current route is collection:object:blog:all entity_type will be object and entity_subtype will be blog. - The all tab will be based on the route collection:<entity_type>:<entity_subtype>:all - The mine tab will be based on the route collection:<entity_type>:<entity_subtype>:owner - The friend tab will be based on the route collection:<entity_type>:<entity_subtype>:friends

If the routes aren’t registered the tabs will not appear.

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 event must return an absolute URL to the registration page.

reload:after, translations

Triggered after the translations are (re)loaded.

sanitize, input

Filter GET and POST input. This is used by get_input() to sanitize user input.

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.

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.

shutdown, system

Triggered after the page has been sent to the user. Expensive operations could be done here and not make the user wait.

Note

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.

Note

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.

Note

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

simplecache:generate, <view>

Filters the view output for a /cache URL when simplecache is enabled.

upgrade, system

Triggered after a system upgrade has finished. All upgrade scripts have run, but the caches are not cleared.

upgrade:execute, system

Triggered when executing an ElggUpgrade. The $object of the event is the ElggUpgrade.

User events

ban, user

Triggered before a user is banned. Return false to prevent.

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 event 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

invalidate:after, user

Triggered when user’s account validation has been revoked.

login, user

Triggered when a user is being logged in.

login:forward, user

Filters the URL to which the user will be forwarded after login.

login:first, user

Triggered after a successful login. Only if there is no previous login.

logout:after, user

Triggered after the user logouts.

logout:before, user

Triggered during logout. Returning false should prevent the user from logging out.

make_admin, user

Triggered before a user is promoted to an admin. Return false to prevent.

profileiconupdate, user

User has changed profile icon

profileupdate, user

User has changed profile

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 event. Event handlers can throw \Elgg\Exceptions\Configuration\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)

registeruser:validate:email, all

Return boolean for if the string in $params['email'] is valid for an email address. Event handler can throw \Elgg\Exceptions\Configuration\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. Event handler can throw \Elgg\Exceptions\Configuration\RegistrationException with an error message to be shown to the user.

registeruser:validate:username, all

Return boolean for if the string in $params['username'] is valid for a username. Event handler can throw \Elgg\Exceptions\Configuration\RegistrationException with an error message to be shown to the user.

remove_admin, user

Triggered before a user is demoted from an admin. Return false to prevent.

unban, user

Triggered before a user is unbanned. Return false to prevent.

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'].

usersettings:save, user

Triggered in the aggregate action to save user settings. The event 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 event handler, as you will override other events’ 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

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.

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

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'].

create, <entity type>

Triggered for user, group, object, and site entities after creation. Triggered just before the create:after event, mostly for BC reasons. The use of the create:after event is preferred.

create:after, <entity type>

Triggered for user, group, object, and site entities after creation.

create:before, <entity type>

Triggered for user, group, object, and site entities before creation. Return false to prevent creating the entity.

delete, <entity type>

Triggered when an entity is permanently removed from the database. Also see Restore capability

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.

likes:count, <entity_type>

Return the number of likes for $params['entity'].

trash, <entity type>

Triggered when an entity is marked as deleted in the database. Also see Restore capability

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.

Metadata events

create, metadata

Called after the metadata has been created. Return false to delete the metadata that was just created.

delete, metadata

Called before metadata is deleted. Return false to prevent deletion.

update, metadata

Called after the metadata has been updated. Return false to delete the metadata.

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.

delete, annotation

Called before annotation is deleted. Return false to prevent deletion.

update, annotation

Called after the annotation has been updated. Return false to delete the annotation.

River events

create:after, river

Called after a river item is created.

create:before, river

Called before the river item is saved to the database. Return false to prevent the item from being created.

delete:after, river

Triggered after a river item was deleted.

delete:before, river

Triggered before a river item is deleted. Returning false cancels the deletion.

Access events

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.

Warning

The handler needs to either not use parts of the API that use the access system (triggering the event 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 elgg_get_write_access_array(), this event 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 event 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 elgg_get_write_access_array() function.

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.

create, access_collection

Triggered during the creation of an ElggAccessCollection.

delete, access_collection

Triggered during the deletion of an ElggAccessCollection.

get_sql, access

Filters SQL clauses restricting/allowing access to entities and annotations.

Note

The event 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

update, access_collection

Triggered during the update of an ElggAccessCollection.

Permission events

container_logic_check, <entity_type>

Triggered by ElggEntity:canWriteToContainer() before triggering permissions_check and container_permissions_check events. Unlike permissions events, 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 event 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 event is null, so the handler can check if another event has modified the value by checking if return value is set. Should this event return false, container_permissions_check and permissions_check events 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 event 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 event 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 event 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: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 event, and its return value is that event’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.

api_key, use

Triggered in the class \Elgg\WebServices\PAM\API\APIKey. 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 \Elgg\Exceptions\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 event 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 events

dequeue, notifications

Called when an ElggData object is removed from the notifications queue to be processed

enqueue, notifications

Called when an ElggData object is being added to the notifications queue

The following events are listed chronologically in the lifetime of the notification event. Note that not all events apply to instant notifications.

enqueue, notification

Can be used to prevent a notification event from sending subscription notifications. Event 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 event 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' event for details

prepare, notification

A high level event 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 event is triggered before a more granular 'prepare', 'notification:<action>:<entity_type>:<entity_subtype>' and after 'send:before', 'notifications. Event 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 event 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 event 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 event can be used to format a notification before it is passed to the 'send', 'notification:<method>' event. Applies to subscriptions and instant notifications. The event handler should return an instance of \Elgg\Notifications\Notification. The event 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' event 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 event allows you to alter an instance of \Elgg\Email before it is passed to the email transport. This event 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.

transport, system:email

Triggered by elgg_send_email(). Applies to all outgoing system and notification emails. This event 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

validate, system:email

Triggered by elgg_send_email(). Applies to all outgoing system and notification emails. This event 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

zend:message, system:email

Triggered by the default email transport handler (Elgg uses laminas/laminas-mail). Applies to all outgoing system and notification emails that were not transported using the transport, system:email event. This event allows you to alter an instance of \Laminas\Mail\Message before it is passed to the Laminas email transport.

$params contains:

• email - An instance of \Elgg\Email

File events

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

• use_cookie - whether or not to use a cookie to secure download link

• expires - a string representation of when the download link should expire

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

• use_cookie - whether or not to use a cookie to secure download link

• expires - a string representation of when the download link should expire

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

The event provides $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

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.

Action events

action:validate, <action>

Trigger before action script/controller is executed. This event should be used to validate/alter user input, before proceeding with the action. The event handler can throw an instance of \Elgg\Exceptions\Http\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.

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 \Elgg\Exceptions\HttpException that triggered the error.

response, action:<action>

Filter an instance of \Elgg\Http\ResponseBuilder before it is sent to the client. This event 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 module is used, this event gives access to the response object (\Elgg\Services\AjaxResponse) so it can be altered/extended. The event type depends on the method call:

elgg/Ajax method	event type
action()	action:<action_name>
path()	path:<url_path>
view()	view:<view_name>
form()	form:<action_name>

ajax_response, action:<action_name>

Filters action/ responses before they’re sent back to the elgg/Ajax module.

ajax_response, path:<path>

Filters ajax responses before they’re sent back to the elgg/Ajax module. This event type will only be used if the path did not start with “action/” or “ajax/”.

ajax_response, view:<view>

Filters ajax/view/ responses before they’re sent back to the elgg/Ajax module.

ajax_response, form:<action_name>

Filters ajax/form/ responses before they’re sent back to the elgg/Ajax module.

Routing

response, path:<path>

Filter an instance of \Elgg\Http\ResponseBuilder before it is sent to the client. This event type will only be used if the path did not start with “action/” or “ajax/”. This event 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 event should use the original <path> to filter the response, or switch to using the route:rewrite event.

route:config, <route_name>

Allows altering the route configuration before it is registered. This event can be used to alter the path, default values, requirements, as well as to set/remove middleware. Please note that the handler for this event 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 event should be registered outside of the init event handler, as route rewrites take place after plugins_boot event has completed.

Views

attributes, htmlawed

Allows changes to individual attributes.

allowed_styles, htmlawed

Configure allowed styles for HTMLawed.

config, htmlawed

Filter the HTMLawed $config array.

form:prepare:fields, <form_name>

Prepare field values for use in the form. Eg. when editing a blog, fill this with the current values of the blog. Sticky form values will automatically be added to the field values (when available).

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'),
      ],
   ],
];

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()

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 event can be used to modify response content, status code, forward URL, or set additional response headers.

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 event can be used to modify response content, status code, forward URL, or set additional response headers.

shell, page

In elgg_view_page(), filters the page shell name

spec, htmlawed

Filter the HTMLawed $spec string (default empty).

table_columns:call, <name>

When the method elgg()->table_columns->$name() is called, this event 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>.

view, <view_name>

Filters the returned content of the view

view_vars, <view_name>

Filters the $vars array passed to the view

Search

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: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'],
];

search:fields, <entity_type>:<entity_subtype>

See search:fields, <entity_type>

search:fields, <search_type>

See search:fields, <entity_type>

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.

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: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: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 event is designed for use by plugins integrating third-party indexing services, such as Solr and Elasticsearch.

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. Use elgg_comments_per_page() to get the value.

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 elgg_get_default_access(), this event 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 event 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 event 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_event_handler('entity:icon:url', 'user', 'gravatar_icon_handler', 600);

/**
 * Default to icon from gravatar for users without avatar.
 *
 * @param \Elgg\Event $event 'entity:icon:url', 'user'
 *
 * @return string|null
 */
function gravatar_icon_handler(\Elgg\Event $event): ?string {
        $entity = $event->getEntityParam();
        $size = $event->getParam('size');

        // Allow users to upload avatars
        if ($entity->hasIcon($size)) {
                return null;
        }

        // Generate gravatar hash for user email
        $hash = md5(strtolower(trim($entity->email)));

        // Default icon size
        $size = '150x150';

        // Use configured size if possible
        $config = elgg_get_icon_sizes('user');
        $key = $event->getParam('size');
        if (isset($config[$key])) {
                $size = $config[$key]['w'] . 'x' . $config[$key]['h'];
        }

        // Produce URL used to retrieve icon
        return "https://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 event 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 event 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 events

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 event 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 event 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>:<entity_subtype>

Return the URL for the entity $params['entity']. Note: Generally it is better to override the getUrl() method of ElggEntity. This event should be used when it’s not possible to subclass (like if you want to extend a bundled plugin without overriding many views).

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 event should be used when it’s not possible to subclass (like if you want to extend a bundled plugin without overriding many views).

extender:url, <annotation|metadata>

Return the URL for the annotation or metadata $params['extender'].

fields, <entity_type>:<entity_subtype>

Return an array of fields usable for elgg_view_field(). The result should be returned as an array of fields. It is required to provide name and #type for each field.

$result = [];

$result[] = [
        '#type' => 'longtext',
        'name' => 'description',
];

return $result;

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(
        'name' => elgg_echo('name'),
        'widget_columns' => 3,
        'widget_context' => $widget_context,

        'event_name' => $event_name,
        'event_type' => $event_type,

        'entity_type' => $entity_type,
        'entity_subtype' => $entity_subtype,
)

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.

maintenance:allow, url

Return boolean if the URL $params['current_url'] and the path $params['current_path']

is allowed during maintenance mode.

plugin_setting, <entity type>

Can be used to change the value of the setting being saved

Params contains: - entity - The ElggEntity where the plugin setting is being saved - plugin_id - The ID of the plugin for which the setting is being saved - name - The name of the setting being saved - value - The original value of the setting being saved

Return value should be a scalar in order to be able to save it to the database. An error will be logged if this is not the case.

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 event, 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

relationship:url, <relationship_name>

Filter the URL for the relationship object $params['relationship'].

robots.txt, site

Filter the robots.txt values for $params['site'].

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

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.

Plugins

Groups

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

Web Services

register, api_methods``

Triggered when the ApiRegistrationService is constructed which allows to add/remove/edit webservice configurations

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