vendor/symfony/event-dispatcher/Symfony/Component/EventDispatcher/EventDispatcher.php

   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  *
  17  * Listeners are registered on the manager and events are dispatched through the
  18  * manager.
  19  *
  20  * @author  Guilherme Blanco <guilhermeblanco@hotmail.com>
  21  * @author  Jonathan Wage <jonwage@gmail.com>
  22  * @author  Roman Borschel <roman@code-factory.org>
  23  * @author  Bernhard Schussek <bschussek@gmail.com>
  24  * @author  Fabien Potencier <fabien@symfony.com>
  25  * @author  Jordi Boggiano <j.boggiano@seld.be>
  26  * @author  Jordan Alliot <jordan.alliot@gmail.com>
  27  *
  28  * @api
  29  */
  30 class EventDispatcher implements EventDispatcherInterface
  31 {
  32     private $listeners = array();
  33     private $sorted = array();
  34
  35     /**
  36      * @see EventDispatcherInterface::dispatch
  37      *
  38      * @api
  39      */
  40     public function dispatch($eventName, Event $event = null)
  41     {
  42         if (null === $event) {
  43             $event = new Event();
  44         }
  45
  46         $event->setDispatcher($this);
  47         $event->setName($eventName);
  48
  49         if (!isset($this->listeners[$eventName])) {
  50             return $event;
  51         }
  52
  53         $this->doDispatch($this->getListeners($eventName), $eventName, $event);
  54
  55         return $event;
  56     }
  57
  58     /**
  59      * @see EventDispatcherInterface::getListeners
  60      */
  61     public function getListeners($eventName = null)
  62     {
  63         if (null !== $eventName) {
  64             if (!isset($this->sorted[$eventName])) {
  65                 $this->sortListeners($eventName);
  66             }
  67
  68             return $this->sorted[$eventName];
  69         }
  70
  71         foreach (array_keys($this->listeners) as $eventName) {
  72             if (!isset($this->sorted[$eventName])) {
  73                 $this->sortListeners($eventName);
  74             }
  75         }
  76
  77         return $this->sorted;
  78     }
  79
  80     /**
  81      * @see EventDispatcherInterface::hasListeners
  82      */
  83     public function hasListeners($eventName = null)
  84     {
  85         return (Boolean) count($this->getListeners($eventName));
  86     }
  87
  88     /**
  89      * @see EventDispatcherInterface::addListener
  90      *
  91      * @api
  92      */
  93     public function addListener($eventName, $listener, $priority = 0)
  94     {
  95         $this->listeners[$eventName][$priority][] = $listener;
  96         unset($this->sorted[$eventName]);
  97     }
  98
  99     /**
 100      * @see EventDispatcherInterface::removeListener
 101      */
 102     public function removeListener($eventName, $listener)
 103     {
 104         if (!isset($this->listeners[$eventName])) {
 105             return;
 106         }
 107
 108         foreach ($this->listeners[$eventName] as $priority => $listeners) {
 109             if (false !== ($key = array_search($listener, $listeners, true))) {
 110                 unset($this->listeners[$eventName][$priority][$key], $this->sorted[$eventName]);
 111             }
 112         }
 113     }
 114
 115     /**
 116      * @see EventDispatcherInterface::addSubscriber
 117      *
 118      * @api
 119      */
 120     public function addSubscriber(EventSubscriberInterface $subscriber)
 121     {
 122         foreach ($subscriber->getSubscribedEvents() as $eventName => $params) {
 123             if (is_string($params)) {
 124                 $this->addListener($eventName, array($subscriber, $params));
 125             } elseif (is_string($params[0])) {
 126                 $this->addListener($eventName, array($subscriber, $params[0]), isset($params[1]) ? $params[1] : 0);
 127             } else {
 128                 foreach ($params as $listener) {
 129                     $this->addListener($eventName, array($subscriber, $listener[0]), isset($listener[1]) ? $listener[1] : 0);
 130                 }
 131             }
 132         }
 133     }
 134
 135     /**
 136      * @see EventDispatcherInterface::removeSubscriber
 137      */
 138     public function removeSubscriber(EventSubscriberInterface $subscriber)
 139     {
 140         foreach ($subscriber->getSubscribedEvents() as $eventName => $params) {
 141             if (is_array($params) && is_array($params[0])) {
 142                 foreach ($params as $listener) {
 143                     $this->removeListener($eventName, array($subscriber, $listener[0]));
 144                 }
 145             } else {
 146                 $this->removeListener($eventName, array($subscriber, is_string($params) ? $params : $params[0]));
 147             }
 148         }
 149     }
 150
 151     /**
 152      * Triggers the listeners of an event.
 153      *
 154      * This method can be overridden to add functionality that is executed
 155      * for each listener.
 156      *
 157      * @param array[callback] $listeners The event listeners.
 158      * @param string          $eventName The name of the event to dispatch.
 159      * @param Event           $event     The event object to pass to the event handlers/listeners.
 160      */
 161     protected function doDispatch($listeners, $eventName, Event $event)
 162     {
 163         foreach ($listeners as $listener) {
 164             call_user_func($listener, $event);
 165             if ($event->isPropagationStopped()) {
 166                 break;
 167             }
 168         }
 169     }
 170
 171     /**
 172      * Sorts the internal list of listeners for the given event by priority.
 173      *
 174      * @param string $eventName The name of the event.
 175      */
 176     private function sortListeners($eventName)
 177     {
 178         $this->sorted[$eventName] = array();
 179
 180         if (isset($this->listeners[$eventName])) {
 181             krsort($this->listeners[$eventName]);
 182             $this->sorted[$eventName] = call_user_func_array('array_merge', $this->listeners[$eventName]);
 183         }
 184     }
 185 }