describe the usage of the RegisterListenersPass

Author: xabbuh

components/event_dispatcher/introduction.rst

@@ -205,6 +205,47 @@ instance of ``Symfony\Component\HttpKernel\Event\FilterResponseEvent``::
  // ...
  }
 
+.. sidebar:: Registering Event Listeners in the Service Container
+
+ When you are using the
+ :doc:`DependencyInjection component </components/dependency_injection/introduction>`,
+ you can use the
+ :class:`Symfony\\Component\\HttpKernel\\DependencyInjection\\RegisterListenersPass`
+ from the HttpKernel component to tag services as event listeners::
+
+ use Symfony\Component\DependencyInjection\ContainerBuilder;
+ use Symfony\Component\DependencyInjection\Definition;
+ use Symfony\Component\DependencyInjection\ParameterBag\ParameterBag;
+ use Symfony\Component\HttpKernel\DependencyInjection\RegisterListenersPass;
+
+ $containerBuilder = new ContainerBuilder(new ParameterBag());
+ $containerBuilder->addCompilerPass(new RegisterListenersPass());
+
+ // register the event dispatcher service
+ $containerBuilder->register(
+ 'event_dispatcher',
+ 'Symfony\Component\EventDispatcher\EventDispatcher'
+ );
+
+ // register your event listener service
+ $listener = new Definition('AcmeListener');
+ $listener->addTag('kernel.event_listener', array(
+ 'event' => 'foo.action',
+ 'method' => 'onFooAction',
+ ));
+ $containerBuilder->setDefinition('listener_service_id', $listener);
+
+ // register an event subscriber
+ $subscriber = new Definition('AcmeSubscriber');
+ $subscriber->addTag('kernel.event_subscriber');
+ $containerBuilder->setDefinition('subscriber_service_id', $subscriber);
+
+ By default, the listeners pass assumes that the event dispatcher's service
+ id is ``event_dispatcher``, that event listeners are tagged with the
+ ``kernel.event_listener`` tag and that event subscribers are tagged with
+ the ``kernel.event_subscriber`` tag. You can change these default values
+ by passing custom values to the constructor of ``RegisterListenersPass``.
+
 .. _event_dispatcher-closures-as-listeners:
 
 .. index::