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: }
186: