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/Symfony 4.1

EventDispatcherInterface

interface EventDispatcherInterface

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.

Methods

Event dispatch(string $eventName, Event $event = null)

Dispatches an event to all registered listeners.

addListener(string $eventName, callable $listener, int $priority = 0)

Adds an event listener that listens on the specified events.

addSubscriber(EventSubscriberInterface $subscriber)

Adds an event subscriber.

removeListener(string $eventName, callable $listener)

Removes an event listener from the specified events.

removeSubscriber(EventSubscriberInterface $subscriber)
array getListeners(string $eventName = null)

Gets the listeners of a specific event or all listeners sorted by descending priority.

int|null getListenerPriority(string $eventName, callable $listener)

Gets the listener priority for a specific event.

bool hasListeners(string $eventName = null)

Checks whether an event has any registered listeners.

Details

Event dispatch(string $eventName, Event $event = null)

Dispatches an event to all registered listeners.

Parameters

string $eventName The name of the event to dispatch. The name of the event is the name of the method that is invoked on listeners.
Event $event The event to pass to the event handlers/listeners If not supplied, an empty Event instance is created

Return Value

Event

addListener(string $eventName, callable $listener, int $priority = 0)

Adds an event listener that listens on the specified events.

Parameters

string $eventName The event to listen on
callable $listener The listener
int $priority The higher this value, the earlier an event listener will be triggered in the chain (defaults to 0)

addSubscriber(EventSubscriberInterface $subscriber)

Adds an event subscriber.

The subscriber is asked for all the events he is interested in and added as a listener for these events.

Parameters

EventSubscriberInterface $subscriber

removeListener(string $eventName, callable $listener)

Removes an event listener from the specified events.

Parameters

string $eventName The event to remove a listener from
callable $listener The listener to remove

removeSubscriber(EventSubscriberInterface $subscriber)

Parameters

EventSubscriberInterface $subscriber

array getListeners(string $eventName = null)

Gets the listeners of a specific event or all listeners sorted by descending priority.

Parameters

string $eventName The name of the event

Return Value

array The event listeners for the specified event, or all event listeners by event name

int|null getListenerPriority(string $eventName, callable $listener)

Gets the listener priority for a specific event.

Returns null if the event or the listener does not exist.

Parameters

string $eventName The name of the event
callable $listener The listener

Return Value

int|null The event listener priority

bool hasListeners(string $eventName = null)

Checks whether an event has any registered listeners.

Parameters

string $eventName The name of the event

Return Value

bool true if the specified event has any listeners, false otherwise

© 2004–2017 Fabien Potencier
Licensed under the MIT License.
https://api.symfony.com/4.1/Symfony/Component/EventDispatcher/EventDispatcherInterface.html