The signature of the EventDispatcherInterface::dispatch() method has been changed to dispatch($event, string $eventName = null): object.
The Event class has been removed in favor of Symfony\Contracts\EventDispatcher\Event.
The TraceableEventDispatcherInterface has been removed.
The WrappedListener class is now final.
4.4.0
AddEventAliasesPass has been added, allowing applications and bundles to extend the event alias mapping used by RegisterListenersPass.
Made the event attribute of the kernel.event_listener tag optional for FQCN events.
4.3.0
The signature of the EventDispatcherInterface::dispatch() method should be updated to dispatch($event, string $eventName = null), not doing so is deprecated
deprecated the Event class, use Symfony\Contracts\EventDispatcher\Event instead
4.1.0
added support for invokable event listeners tagged with kernel.event_listener by default
The TraceableEventDispatcher::getOrphanedEvents() method has been added.
The TraceableEventDispatcherInterface has been deprecated.
4.0.0
removed the ContainerAwareEventDispatcher class
added the reset() method to the TraceableEventDispatcherInterface
3.4.0
Implementing TraceableEventDispatcherInterface without the reset() method has been deprecated.
3.3.0
The ContainerAwareEventDispatcher class has been deprecated. Use EventDispatcher with closure factories instead.
3.0.0
The method getListenerPriority($eventName, $listener) has been added to the
EventDispatcherInterface.
The methods Event::setDispatcher(), Event::getDispatcher(), Event::setName()
and Event::getName() have been removed.
The event dispatcher and the event name are passed to the listener call.
2.5.0
added Debug\TraceableEventDispatcher (originally in HttpKernel)
changed Debug\TraceableEventDispatcherInterface to extend EventDispatcherInterface
added RegisterListenersPass (originally in HttpKernel)
2.1.0
added TraceableEventDispatcherInterface
added ContainerAwareEventDispatcher
added a reference to the EventDispatcher on the Event
added a reference to the Event name on the event
added fluid interface to the dispatch() method which now returns the Event
object
added GenericEvent event class
added the possibility for subscribers to subscribe several times for the
same event
