. */ namespace Doctrine\Common; /** * The EventManager is the central point of Doctrine's event listener system. * Listeners are registered on the manager and events are dispatched through the * manager. * * @link www.doctrine-project.org * @since 2.0 * @author Guilherme Blanco * @author Jonathan Wage * @author Roman Borschel */ class EventManager { /** * Map of registered listeners. * => * * @var array */ private $_listeners = []; /** * Dispatches an event to all registered listeners. * * @param string $eventName The name of the event to dispatch. The name of the event is * the name of the method that is invoked on listeners. * @param EventArgs|null $eventArgs The event arguments to pass to the event handlers/listeners. * If not supplied, the single empty EventArgs instance is used. * * @return void */ public function dispatchEvent($eventName, EventArgs $eventArgs = null) { if (isset($this->_listeners[$eventName])) { $eventArgs = $eventArgs === null ? EventArgs::getEmptyInstance() : $eventArgs; foreach ($this->_listeners[$eventName] as $listener) { $listener->$eventName($eventArgs); } } } /** * Gets the listeners of a specific event or all listeners. * * @param string|null $event The name of the event. * * @return array The event listeners for the specified event, or all event listeners. */ public function getListeners($event = null) { return $event ? $this->_listeners[$event] : $this->_listeners; } /** * Checks whether an event has any registered listeners. * * @param string $event * * @return boolean TRUE if the specified event has any listeners, FALSE otherwise. */ public function hasListeners($event) { return !empty($this->_listeners[$event]); } /** * Adds an event listener that listens on the specified events. * * @param string|array $events The event(s) to listen on. * @param object $listener The listener object. * * @return void */ public function addEventListener($events, $listener) { // Picks the hash code related to that listener $hash = spl_object_hash($listener); foreach ((array) $events as $event) { // Overrides listener if a previous one was associated already // Prevents duplicate listeners on same event (same instance only) $this->_listeners[$event][$hash] = $listener; } } /** * Removes an event listener from the specified events. * * @param string|array $events * @param object $listener * * @return void */ public function removeEventListener($events, $listener) { // Picks the hash code related to that listener $hash = spl_object_hash($listener); foreach ((array) $events as $event) { unset($this->_listeners[$event][$hash]); } } /** * Adds an EventSubscriber. The subscriber is asked for all the events it is * interested in and added as a listener for these events. * * @param \Doctrine\Common\EventSubscriber $subscriber The subscriber. * * @return void */ public function addEventSubscriber(EventSubscriber $subscriber) { $this->addEventListener($subscriber->getSubscribedEvents(), $subscriber); } /** * Removes an EventSubscriber. The subscriber is asked for all the events it is * interested in and removed as a listener for these events. * * @param \Doctrine\Common\EventSubscriber $subscriber The subscriber. * * @return void */ public function removeEventSubscriber(EventSubscriber $subscriber) { $this->removeEventListener($subscriber->getSubscribedEvents(), $subscriber); } }