1 <?php

     2 

     3 /*

     4  * This file is part of the Symfony package.

     5  *

     6  * (c) Fabien Potencier <fabien@symfony.com>

     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 <bschussek@gmail.com>

    20  *

    21  * @api

    22  */

    23 interface EventDispatcherInterface

    24 {

    25     /**

    26      * Dispatches an event to all registered listeners.

    27      *

    28      * @param string $eventName The name of the event to dispatch. The name of

    29      *                          the event is the name of the method that is

    30      *                          invoked on listeners.

    31      * @param Event $event The event to pass to the event handlers/listeners.

    32      *                     If not supplied, an empty Event instance is created.

    33      *

    34      * @api

    35      */

    36     function dispatch($eventName, Event $event = null);

    37 

    38     /**

    39      * Adds an event listener that listens on the specified events.

    40      *

    41      * @param string   $eventName The event to listen on

    42      * @param callable $listener  The listener

    43      * @param integer  $priority  The higher this value, the earlier an event

    44      *                            listener will be triggered in the chain (defaults to 0)

    45      *

    46      * @api

    47      */

    48     function addListener($eventName, $listener, $priority = 0);

    49 

    50     /**

    51      * Adds an event subscriber. The subscriber is asked for all the events he is

    52      * interested in and added as a listener for these events.

    53      *

    54      * @param EventSubscriberInterface $subscriber The subscriber.

    55      *

    56      * @api

    57      */

    58     function addSubscriber(EventSubscriberInterface $subscriber);

    59 

    60     /**

    61      * Removes an event listener from the specified events.

    62      *

    63      * @param string|array $eventName The event(s) to remove a listener from.

    64      * @param object $listener The listener object to remove.

    65      */

    66     function removeListener($eventName, $listener);

    67 

    68     /**

    69      * Removes an event subscriber.

    70      *

    71      * @param EventSubscriberInterface $subscriber The subscriber.

    72      */

    73     function removeSubscriber(EventSubscriberInterface $subscriber);

    74 

    75     /**

    76      * Gets the listeners of a specific event or all listeners.

    77      *

    78      * @param string $eventName The name of the event.

    79      *

    80      * @return array The event listeners for the specified event, or all event

    81      *               listeners by event name.

    82      */

    83     function getListeners($eventName = null);

    84 

    85     /**

    86      * Checks whether an event has any registered listeners.

    87      *

    88      * @param string $eventName The name of the event.

    89      *

    90      * @return Boolean TRUE if the specified event has any listeners, FALSE

    91      *                 otherwise.

    92      */

    93     function hasListeners($eventName = null);

    94 }