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
Expanded class hierarchy of EventDispatcher
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]);
}
}
}