Chris@0: <?php
Chris@0: 
Chris@0: /*
Chris@0:  * This file is part of the Symfony package.
Chris@0:  *
Chris@0:  * (c) Fabien Potencier <fabien@symfony.com>
Chris@0:  *
Chris@0:  * For the full copyright and license information, please view the LICENSE
Chris@0:  * file that was distributed with this source code.
Chris@0:  */
Chris@0: 
Chris@0: namespace Symfony\Component\EventDispatcher;
Chris@0: 
Chris@0: /**
Chris@0:  * The EventDispatcherInterface is the central point of Symfony's event listener system.
Chris@0:  * Listeners are registered on the manager and events are dispatched through the
Chris@0:  * manager.
Chris@0:  *
Chris@0:  * @author Bernhard Schussek <bschussek@gmail.com>
Chris@0:  */
Chris@0: interface EventDispatcherInterface
Chris@0: {
Chris@0:     /**
Chris@0:      * Dispatches an event to all registered listeners.
Chris@0:      *
Chris@17:      * @param string     $eventName The name of the event to dispatch. The name of
Chris@17:      *                              the event is the name of the method that is
Chris@17:      *                              invoked on listeners.
Chris@17:      * @param Event|null $event     The event to pass to the event handlers/listeners
Chris@17:      *                              If not supplied, an empty Event instance is created
Chris@0:      *
Chris@0:      * @return Event
Chris@0:      */
Chris@0:     public function dispatch($eventName, Event $event = null);
Chris@0: 
Chris@0:     /**
Chris@0:      * Adds an event listener that listens on the specified events.
Chris@0:      *
Chris@0:      * @param string   $eventName The event to listen on
Chris@0:      * @param callable $listener  The listener
Chris@0:      * @param int      $priority  The higher this value, the earlier an event
Chris@0:      *                            listener will be triggered in the chain (defaults to 0)
Chris@0:      */
Chris@0:     public function addListener($eventName, $listener, $priority = 0);
Chris@0: 
Chris@0:     /**
Chris@0:      * Adds an event subscriber.
Chris@0:      *
Chris@17:      * The subscriber is asked for all the events it is
Chris@0:      * interested in and added as a listener for these events.
Chris@0:      */
Chris@0:     public function addSubscriber(EventSubscriberInterface $subscriber);
Chris@0: 
Chris@0:     /**
Chris@0:      * Removes an event listener from the specified events.
Chris@0:      *
Chris@0:      * @param string   $eventName The event to remove a listener from
Chris@0:      * @param callable $listener  The listener to remove
Chris@0:      */
Chris@0:     public function removeListener($eventName, $listener);
Chris@0: 
Chris@0:     public function removeSubscriber(EventSubscriberInterface $subscriber);
Chris@0: 
Chris@0:     /**
Chris@0:      * Gets the listeners of a specific event or all listeners sorted by descending priority.
Chris@0:      *
Chris@17:      * @param string|null $eventName The name of the event
Chris@0:      *
Chris@0:      * @return array The event listeners for the specified event, or all event listeners by event name
Chris@0:      */
Chris@0:     public function getListeners($eventName = null);
Chris@0: 
Chris@0:     /**
Chris@0:      * Gets the listener priority for a specific event.
Chris@0:      *
Chris@0:      * Returns null if the event or the listener does not exist.
Chris@0:      *
Chris@0:      * @param string   $eventName The name of the event
Chris@0:      * @param callable $listener  The listener
Chris@0:      *
Chris@0:      * @return int|null The event listener priority
Chris@0:      */
Chris@0:     public function getListenerPriority($eventName, $listener);
Chris@0: 
Chris@0:     /**
Chris@0:      * Checks whether an event has any registered listeners.
Chris@0:      *
Chris@17:      * @param string|null $eventName The name of the event
Chris@0:      *
Chris@0:      * @return bool true if the specified event has any listeners, false otherwise
Chris@0:      */
Chris@0:     public function hasListeners($eventName = null);
Chris@0: }