<?php
/*
* This file is part of the Symfony package.
*
* (c) Fabien Potencier <[email protected]>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace Symfony\Component\EventDispatcher;
/**
* 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.
*
* @author Bernhard Schussek <[email protected]>
*/
interface EventDispatcherInterface
{
/**
* Dispatches an event to all registered listeners.
*
* @param 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.
* @param Event $event The event to pass to the event handlers/listeners.
* If not supplied, an empty Event instance is created.
*
* @return Event
*/
public function dispatch($eventName, Event $event = null);
/**
* Adds an event listener that listens on the specified events.
*
* @param string $eventName The event to listen on
* @param callable $listener The listener
* @param int $priority The higher this value, the earlier an event
* listener will be triggered in the chain (defaults to 0)
*/
public function addListener($eventName, $listener, $priority = 0);
/**
* Adds an event subscriber.
*
* The subscriber is asked for all the events he is
* interested in and added as a listener for these events.
*
* @param EventSubscriberInterface $subscriber The subscriber.
*/
public function addSubscriber(EventSubscriberInterface $subscriber);
/**
* Removes an event listener from the specified events.
*
* @param string $eventName The event to remove a listener from
* @param callable $listener The listener to remove
*/
public function removeListener($eventName, $listener);
/**
* Removes an event subscriber.
*
* @param EventSubscriberInterface $subscriber The subscriber
*/
public function removeSubscriber(EventSubscriberInterface $subscriber);
/**
* Gets the listeners of a specific event or all listeners sorted by descending priority.
*
* @param string $eventName The name of the event
*
* @return array The event listeners for the specified event, or all event listeners by event name
*/
public function getListeners($eventName = null);
/**
* Checks whether an event has any registered listeners.
*
* @param string $eventName The name of the event
*
* @return bool true if the specified event has any listeners, false otherwise
*/
public function hasListeners($eventName = null);
}