class 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 Guilherme Blanco <guilhermeblanco@hotmail.com> @author Jonathan Wage <jonwage@gmail.com> @author Roman Borschel <roman@code-factory.org> @author Bernhard Schussek <bschussek@gmail.com> @author Fabien Potencier <fabien@symfony.com> @author Jordi Boggiano <j.boggiano@seld.be> @author Jordan Alliot <jordan.alliot@gmail.com>

@api

Hierarchy

Expanded class hierarchy of EventDispatcher

14 files declare their use of EventDispatcher
AbstractHasDispatcher.php in drupal/core/vendor/guzzle/common/Guzzle/Common/AbstractHasDispatcher.php
Config.php in drupal/core/lib/Drupal/Core/Config/Config.php
Definition of Drupal\Core\Config\Config.
ConfigFactory.php in drupal/core/lib/Drupal/Core/Config/ConfigFactory.php
Definition of Drupal\Core\Config\ConfigFactory.
EsiListenerTest.php in drupal/core/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/Tests/EventListener/EsiListenerTest.php
EventDataCollectorTest.php in drupal/core/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/Tests/DataCollector/EventDataCollectorTest.php

... See full list

File

drupal/core/vendor/symfony/event-dispatcher/Symfony/Component/EventDispatcher/EventDispatcher.php, line 30

Namespace

Symfony\Component\EventDispatcher
View source
class EventDispatcher implements EventDispatcherInterface {
  private $listeners = array();
  private $sorted = array();

  /**
   * @see EventDispatcherInterface::dispatch
   *
   * @api
   */
  public function dispatch($eventName, Event $event = null) {
    if (null === $event) {
      $event = new Event();
    }
    $event
      ->setDispatcher($this);
    $event
      ->setName($eventName);
    if (!isset($this->listeners[$eventName])) {
      return $event;
    }
    $this
      ->doDispatch($this
      ->getListeners($eventName), $eventName, $event);
    return $event;
  }

  /**
   * @see EventDispatcherInterface::getListeners
   */
  public function getListeners($eventName = null) {
    if (null !== $eventName) {
      if (!isset($this->sorted[$eventName])) {
        $this
          ->sortListeners($eventName);
      }
      return $this->sorted[$eventName];
    }
    foreach (array_keys($this->listeners) as $eventName) {
      if (!isset($this->sorted[$eventName])) {
        $this
          ->sortListeners($eventName);
      }
    }
    return $this->sorted;
  }

  /**
   * @see EventDispatcherInterface::hasListeners
   */
  public function hasListeners($eventName = null) {
    return (bool) count($this
      ->getListeners($eventName));
  }

  /**
   * @see EventDispatcherInterface::addListener
   *
   * @api
   */
  public function addListener($eventName, $listener, $priority = 0) {
    $this->listeners[$eventName][$priority][] = $listener;
    unset($this->sorted[$eventName]);
  }

  /**
   * @see EventDispatcherInterface::removeListener
   */
  public function removeListener($eventName, $listener) {
    if (!isset($this->listeners[$eventName])) {
      return;
    }
    foreach ($this->listeners[$eventName] as $priority => $listeners) {
      if (false !== ($key = array_search($listener, $listeners))) {
        unset($this->listeners[$eventName][$priority][$key], $this->sorted[$eventName]);
      }
    }
  }

  /**
   * @see EventDispatcherInterface::addSubscriber
   *
   * @api
   */
  public function addSubscriber(EventSubscriberInterface $subscriber) {
    foreach ($subscriber
      ->getSubscribedEvents() as $eventName => $params) {
      if (is_string($params)) {
        $this
          ->addListener($eventName, array(
          $subscriber,
          $params,
        ));
      }
      elseif (is_string($params[0])) {
        $this
          ->addListener($eventName, array(
          $subscriber,
          $params[0],
        ), isset($params[1]) ? $params[1] : 0);
      }
      else {
        foreach ($params as $listener) {
          $this
            ->addListener($eventName, array(
            $subscriber,
            $listener[0],
          ), isset($listener[1]) ? $listener[1] : 0);
        }
      }
    }
  }

  /**
   * @see EventDispatcherInterface::removeSubscriber
   */
  public function removeSubscriber(EventSubscriberInterface $subscriber) {
    foreach ($subscriber
      ->getSubscribedEvents() as $eventName => $params) {
      if (is_array($params) && is_array($params[0])) {
        foreach ($params as $listener) {
          $this
            ->removeListener($eventName, array(
            $subscriber,
            $listener[0],
          ));
        }
      }
      else {
        $this
          ->removeListener($eventName, array(
          $subscriber,
          is_string($params) ? $params : $params[0],
        ));
      }
    }
  }

  /**
   * Triggers the listeners of an event.
   *
   * This method can be overridden to add functionality that is executed
   * for each listener.
   *
   * @param array[callback] $listeners The event listeners.
   * @param string          $eventName The name of the event to dispatch.
   * @param Event           $event     The event object to pass to the event handlers/listeners.
   */
  protected function doDispatch($listeners, $eventName, Event $event) {
    foreach ($listeners as $listener) {
      call_user_func($listener, $event);
      if ($event
        ->isPropagationStopped()) {
        break;
      }
    }
  }

  /**
   * Sorts the internal list of listeners for the given event by priority.
   *
   * @param string $eventName The name of the event.
   */
  private function sortListeners($eventName) {
    $this->sorted[$eventName] = array();
    if (isset($this->listeners[$eventName])) {
      krsort($this->listeners[$eventName]);
      $this->sorted[$eventName] = call_user_func_array('array_merge', $this->listeners[$eventName]);
    }
  }

}

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