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: use Symfony\Component\DependencyInjection\ContainerInterface;
 15: 
 16: /**
 17:  * Lazily loads listeners and subscribers from the dependency injection
 18:  * container.
 19:  *
 20:  * @author Fabien Potencier <fabien@symfony.com>
 21:  * @author Bernhard Schussek <bschussek@gmail.com>
 22:  * @author Jordan Alliot <jordan.alliot@gmail.com>
 23:  */
 24: class ContainerAwareEventDispatcher extends EventDispatcher
 25: {
 26:     /**
 27:      * The container from where services are loaded.
 28:      *
 29:      * @var ContainerInterface
 30:      */
 31:     private $container;
 32: 
 33:     /**
 34:      * The service IDs of the event listeners and subscribers.
 35:      *
 36:      * @var array
 37:      */
 38:     private $listenerIds = array();
 39: 
 40:     /**
 41:      * The services registered as listeners.
 42:      *
 43:      * @var array
 44:      */
 45:     private $listeners = array();
 46: 
 47:     /**
 48:      * Constructor.
 49:      *
 50:      * @param ContainerInterface $container A ContainerInterface instance
 51:      */
 52:     public function __construct(ContainerInterface $container)
 53:     {
 54:         $this->container = $container;
 55:     }
 56: 
 57:     /**
 58:      * Adds a service as event listener.
 59:      *
 60:      * @param string $eventName Event for which the listener is added
 61:      * @param array  $callback  The service ID of the listener service & the method
 62:      *                          name that has to be called
 63:      * @param int    $priority  The higher this value, the earlier an event listener
 64:      *                          will be triggered in the chain.
 65:      *                          Defaults to 0.
 66:      *
 67:      * @throws \InvalidArgumentException
 68:      */
 69:     public function addListenerService($eventName, $callback, $priority = 0)
 70:     {
 71:         if (!is_array($callback) || 2 !== count($callback)) {
 72:             throw new \InvalidArgumentException('Expected an array("service", "method") argument');
 73:         }
 74: 
 75:         $this->listenerIds[$eventName][] = array($callback[0], $callback[1], $priority);
 76:     }
 77: 
 78:     public function removeListener($eventName, $listener)
 79:     {
 80:         $this->lazyLoad($eventName);
 81: 
 82:         if (isset($this->listenerIds[$eventName])) {
 83:             foreach ($this->listenerIds[$eventName] as $i => $args) {
 84:                 list($serviceId, $method, $priority) = $args;
 85:                 $key = $serviceId.'.'.$method;
 86:                 if (isset($this->listeners[$eventName][$key]) && $listener === array($this->listeners[$eventName][$key], $method)) {
 87:                     unset($this->listeners[$eventName][$key]);
 88:                     if (empty($this->listeners[$eventName])) {
 89:                         unset($this->listeners[$eventName]);
 90:                     }
 91:                     unset($this->listenerIds[$eventName][$i]);
 92:                     if (empty($this->listenerIds[$eventName])) {
 93:                         unset($this->listenerIds[$eventName]);
 94:                     }
 95:                 }
 96:             }
 97:         }
 98: 
 99:         parent::removeListener($eventName, $listener);
100:     }
101: 
102:     /**
103:      * @see EventDispatcherInterface::hasListeners()
104:      */
105:     public function hasListeners($eventName = null)
106:     {
107:         if (null === $eventName) {
108:             return (bool) count($this->listenerIds) || (bool) count($this->listeners);
109:         }
110: 
111:         if (isset($this->listenerIds[$eventName])) {
112:             return true;
113:         }
114: 
115:         return parent::hasListeners($eventName);
116:     }
117: 
118:     /**
119:      * @see EventDispatcherInterface::getListeners()
120:      */
121:     public function getListeners($eventName = null)
122:     {
123:         if (null === $eventName) {
124:             foreach (array_keys($this->listenerIds) as $serviceEventName) {
125:                 $this->lazyLoad($serviceEventName);
126:             }
127:         } else {
128:             $this->lazyLoad($eventName);
129:         }
130: 
131:         return parent::getListeners($eventName);
132:     }
133: 
134:     /**
135:      * Adds a service as event subscriber.
136:      *
137:      * @param string $serviceId The service ID of the subscriber service
138:      * @param string $class     The service's class name (which must implement EventSubscriberInterface)
139:      */
140:     public function addSubscriberService($serviceId, $class)
141:     {
142:         foreach ($class::getSubscribedEvents() as $eventName => $params) {
143:             if (is_string($params)) {
144:                 $this->listenerIds[$eventName][] = array($serviceId, $params, 0);
145:             } elseif (is_string($params[0])) {
146:                 $this->listenerIds[$eventName][] = array($serviceId, $params[0], isset($params[1]) ? $params[1] : 0);
147:             } else {
148:                 foreach ($params as $listener) {
149:                     $this->listenerIds[$eventName][] = array($serviceId, $listener[0], isset($listener[1]) ? $listener[1] : 0);
150:                 }
151:             }
152:         }
153:     }
154: 
155:     /**
156:      * {@inheritdoc}
157:      *
158:      * Lazily loads listeners for this event from the dependency injection
159:      * container.
160:      *
161:      * @throws \InvalidArgumentException if the service is not defined
162:      */
163:     public function dispatch($eventName, Event $event = null)
164:     {
165:         $this->lazyLoad($eventName);
166: 
167:         return parent::dispatch($eventName, $event);
168:     }
169: 
170:     public function getContainer()
171:     {
172:         return $this->container;
173:     }
174: 
175:     /**
176:      * Lazily loads listeners for this event from the dependency injection
177:      * container.
178:      *
179:      * @param string $eventName The name of the event to dispatch. The name of
180:      *                          the event is the name of the method that is
181:      *                          invoked on listeners.
182:      */
183:     protected function lazyLoad($eventName)
184:     {
185:         if (isset($this->listenerIds[$eventName])) {
186:             foreach ($this->listenerIds[$eventName] as $args) {
187:                 list($serviceId, $method, $priority) = $args;
188:                 $listener = $this->container->get($serviceId);
189: 
190:                 $key = $serviceId.'.'.$method;
191:                 if (!isset($this->listeners[$eventName][$key])) {
192:                     $this->addListener($eventName, array($listener, $method), $priority);
193:                 } elseif ($listener !== $this->listeners[$eventName][$key]) {
194:                     parent::removeListener($eventName, array($this->listeners[$eventName][$key], $method));
195:                     $this->addListener($eventName, array($listener, $method), $priority);
196:                 }
197: 
198:                 $this->listeners[$eventName][$key] = $listener;
199:             }
200:         }
201:     }
202: }
203: