【symfony】EventDispatcherInterface.php

  1 <?php
  2
  3 /*
  4  * This file is part of the Symfony package.
  5  *
  6  * (c) Fabien Potencier <[email protected]>
  7  *
  8  * For the full copyright and license information, please view the LICENSE
  9  * file that was distributed with this source code.
 10  */
 11
 12 namespace Symfony\Component\EventDispatcher;
 13
 14 /**
 15  * The EventDispatcherInterface is the central point of Symfony‘s event listener system.
 16  * Listeners are registered on the manager and events are dispatched through the
 17  * manager.
 18  *
 19  * @author Bernhard Schussek <[email protected]>
 20  */
 21 interface EventDispatcherInterface
 22 {
 23     /**
 24      * Dispatches an event to all registered listeners.
 25      *
 26      * @param string $eventName The name of the event to dispatch. The name of
 27      *                          the event is the name of the method that is
 28      *                          invoked on listeners.
 29      * @param Event  $event     The event to pass to the event handlers/listeners.
 30      *                          If not supplied, an empty Event instance is created.
 31      *
 32      * @return Event
 33      */
 34     public function dispatch($eventName, Event $event = null);
 35
 36     /**
 37      * Adds an event listener that listens on the specified events.
 38      *
 39      * @param string   $eventName The event to listen on
 40      * @param callable $listener  The listener
 41      * @param int      $priority  The higher this value, the earlier an event
 42      *                            listener will be triggered in the chain (defaults to 0)
 43      */
 44     public function addListener($eventName, $listener, $priority = 0);
 45
 46     /**
 47      * Adds an event subscriber.
 48      *
 49      * The subscriber is asked for all the events he is
 50      * interested in and added as a listener for these events.
 51      *
 52      * @param EventSubscriberInterface $subscriber The subscriber.
 53      */
 54     public function addSubscriber(EventSubscriberInterface $subscriber);
 55
 56     /**
 57      * Removes an event listener from the specified events.
 58      *
 59      * @param string   $eventName The event to remove a listener from
 60      * @param callable $listener  The listener to remove
 61      */
 62     public function removeListener($eventName, $listener);
 63
 64     /**
 65      * Removes an event subscriber.
 66      *
 67      * @param EventSubscriberInterface $subscriber The subscriber
 68      */
 69     public function removeSubscriber(EventSubscriberInterface $subscriber);
 70
 71     /**
 72      * Gets the listeners of a specific event or all listeners sorted by descending priority.
 73      *
 74      * @param string $eventName The name of the event
 75      *
 76      * @return array The event listeners for the specified event, or all event listeners by event name
 77      */
 78     public function getListeners($eventName = null);
 79
 80     /**
 81      * Gets the listener priority for a specific event.
 82      *
 83      * Returns null if the event or the listener does not exist.
 84      *
 85      * @param string   $eventName The name of the event
 86      * @param callable $listener  The listener
 87      *
 88      * @return int|null The event listener priority
 89      */
 90     public function getListenerPriority($eventName, $listener);
 91
 92     /**
 93      * Checks whether an event has any registered listeners.
 94      *
 95      * @param string $eventName The name of the event
 96      *
 97      * @return bool true if the specified event has any listeners, false otherwise
 98      */
 99     public function hasListeners($eventName = null);
100 }