EventDispatcher
class EventDispatcher implements 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.  |  |
| 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.  |  |
|  addListener(string $eventName, callable $listener, int $priority)  Adds an event listener that listens on the specified events.  |  ||
|  removeListener(string $eventName, callable $listener)  Removes an event listener from the specified events.  |  ||
|  addSubscriber(EventSubscriberInterface $subscriber)  Adds an event subscriber.  |  ||
| removeSubscriber(EventSubscriberInterface $subscriber) | 
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 | 
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 | 
addListener(string $eventName, callable $listener, int $priority)
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) | 
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 | 
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 | 
removeSubscriber(EventSubscriberInterface $subscriber)
Parameters
| EventSubscriberInterface | $subscriber | 
    © 2004–2017 Fabien Potencier
Licensed under the MIT License.
    http://api.symfony.com/3.4/Symfony/Component/EventDispatcher/EventDispatcher.html