CiviEventDispatcherInterface
in
The EventDispatcherInterface is the central point of Symfony's event listener system.
Listeners are registered on the manager and events are dispatched through the manager.
Tags
Table of Contents
Methods
- addListener() : mixed
- Adds an event listener that listens on the specified events.
- addSubscriber() : mixed
- Adds an event subscriber.
- dispatch() : object
- Dispatches an event to all registered listeners.
- getListenerPriority() : int|null
- Gets the listener priority for a specific event.
- getListeners() : array<string|int, mixed>
- Gets the listeners of a specific event or all listeners sorted by descending priority.
- hasListeners() : bool
- Checks whether an event has any registered listeners.
- removeListener() : mixed
- Removes an event listener from the specified events.
- removeSubscriber() : mixed
Methods
addListener()
Adds an event listener that listens on the specified events.
public
addListener(string $eventName, callable $listener[, int $priority = 0 ]) : mixed
Parameters
- $eventName : string
-
The event to listen on
- $listener : callable
-
The listener
- $priority : int = 0
-
The higher this value, the earlier an event listener will be triggered in the chain (defaults to 0)
addSubscriber()
Adds an event subscriber.
public
addSubscriber(EventSubscriberInterface $subscriber) : mixed
The subscriber is asked for all the events it is interested in and added as a listener for these events.
Parameters
- $subscriber : EventSubscriberInterface
dispatch()
Dispatches an event to all registered listeners.
public
dispatch(string $eventName[, object|null $event = NULL ]) : object
Parameters
- $eventName : string
-
The name of the event to dispatch. The name of the event is the name of the method that is invoked on listeners.
- $event : object|null = NULL
-
The event to pass to the event handlers/listeners The dispatcher technically accepts any kind of event-object.
CiviCRM typically uses GenericHookEvent. Specifically:
- For
hook_civicrm_*, GenericHookEvent is strongly required. - For
civi.*, GenericHookEvent is typical but not strongly required.
Symfony also defines classes for event-objects (
Event,GenericEvent). Historically, these types -were- mandatory, but they have had poor interoperability (across versions/environments).GenericHookEventhas provided easier interoperability.Looking forward, the current dispatcher does not specifically require any single type, and there may be use-cases where libraries or extensions define other types. The suitability of this is left as an exercise to the reader.
If $event is a null, then an empty placeholder (
GenericHookEvent) is used. - For
Return values
object —The final event object.
getListenerPriority()
Gets the listener priority for a specific event.
public
getListenerPriority(string $eventName, callable $listener) : int|null
Returns null if the event or the listener does not exist.
Parameters
- $eventName : string
-
The name of the event
- $listener : callable
-
The listener
Return values
int|null —The event listener priority
getListeners()
Gets the listeners of a specific event or all listeners sorted by descending priority.
public
getListeners([string|null $eventName = NULL ]) : array<string|int, mixed>
Parameters
- $eventName : string|null = NULL
-
The name of the event
Return values
array<string|int, mixed> —The event listeners for the specified event, or all event listeners by event name
hasListeners()
Checks whether an event has any registered listeners.
public
hasListeners([string|null $eventName = NULL ]) : bool
Parameters
- $eventName : string|null = NULL
-
The name of the event
Return values
bool —true if the specified event has any listeners, false otherwise
removeListener()
Removes an event listener from the specified events.
public
removeListener(string $eventName, callable $listener) : mixed
Parameters
- $eventName : string
-
The event to remove a listener from
- $listener : callable
-
The listener to remove
removeSubscriber()
public
removeSubscriber(EventSubscriberInterface $subscriber) : mixed
Parameters
- $subscriber : EventSubscriberInterface