<?php
namespace Doctrine\Common;
use Doctrine\Deprecations\Deprecation;
use function spl_object_hash;
/**
* 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.
*/
class EventManager
{
/**
* Map of registered listeners.
* <event> => <listeners>
*
* @var array<string, object[]>
*/
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])) {
return;
}
$eventArgs = $eventArgs ?? EventArgs::getEmptyInstance();
foreach ($this->listeners[$eventName] as $listener) {
$listener->$eventName($eventArgs);
}
}
/**
* Gets the listeners of a specific event.
*
* @param string|null $event The name of the event.
*
* @return object[]|array<string, object[]> The event listeners for the specified event, or all event listeners.
* @psalm-return ($event is null ? array<string, object[]> : object[])
*/
public function getListeners($event = null)
{
if ($event === null) {
Deprecation::trigger(
'doctrine/event-manager',
'https://github.com/doctrine/event-manager/pull/50',
'Calling %s without an event name is deprecated. Call getAllListeners() instead.',
__METHOD__
);
return $this->getAllListeners();
}
return $this->listeners[$event] ?? [];
}
/**
* Gets all listeners keyed by event name.
*
* @return array<string, object[]> The event listeners for the specified event, or all event listeners.
*/
public function getAllListeners(): array
{
return $this->listeners;
}
/**
* Checks whether an event has any registered listeners.
*
* @param string $event
*
* @return bool TRUE if the specified event has any listeners, FALSE otherwise.
*/
public function hasListeners($event)
{
return ! empty($this->listeners[$event]);
}
/**
* Adds an event listener that listens on the specified events.
*
* @param string|string[] $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|string[] $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 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 EventSubscriber $subscriber The subscriber.
*
* @return void
*/
public function removeEventSubscriber(EventSubscriber $subscriber)
{
$this->removeEventListener($subscriber->getSubscribedEvents(), $subscriber);
}
}