发布于 2015-08-27 16:47:45 | 159 次阅读 | 评论: 0 | 来源: 网络整理
The ContainerAwareEventDispatcher is
a special EventDispatcher implementation which is coupled to the service container
that is part of the DependencyInjection component.
It allows services to be specified as event listeners making the EventDispatcher
extremely powerful.
Services are lazy loaded meaning the services attached as listeners will only be created if an event is dispatched that requires those listeners.
Setup is straightforward by injecting a ContainerInterface
into the ContainerAwareEventDispatcher:
use SymfonyComponentDependencyInjectionContainerBuilder;
use SymfonyComponentEventDispatcherContainerAwareEventDispatcher;
$container = new ContainerBuilder();
$dispatcher = new ContainerAwareEventDispatcher($container);
The Container Aware EventDispatcher can either load specified services
directly, or services that implement EventSubscriberInterface.
The following examples assume the service container has been loaded with any services that are mentioned.
注解
Services must be marked as public in the container.
To connect existing service definitions, use the
addListenerService()
method where the $callback is an array of array($serviceId, $methodName):
$dispatcher->addListenerService($eventName, array('foo', 'logListener'));
EventSubscribers can be added using the
addSubscriberService()
method where the first argument is the service ID of the subscriber service,
and the second argument is the service’s class name (which must implement
EventSubscriberInterface) as follows:
$dispatcher->addSubscriberService(
'kernel.store_subscriber',
'StoreSubscriber'
);
The EventSubscriberInterface will be exactly as you would expect:
use SymfonyComponentEventDispatcherEventSubscriberInterface;
// ...
class StoreSubscriber implements EventSubscriberInterface
{
public static function getSubscribedEvents()
{
return array(
'kernel.response' => array(
array('onKernelResponsePre', 10),
array('onKernelResponsePost', 0),
),
'store.order' => array('onStoreOrder', 0),
);
}
public function onKernelResponsePre(FilterResponseEvent $event)
{
// ...
}
public function onKernelResponsePost(FilterResponseEvent $event)
{
// ...
}
public function onStoreOrder(FilterOrderEvent $event)
{
// ...
}
}