Events|Lumen 中文文档

Basic Usage
The Lumen and Laravel event facilities provides a simple observer implementation, allowing you to subscribe and listen for events in your application.

Subscribing To An Event
Note: If you intend to use the Event facade, be sure to uncomment the $app->withFacades() call in your bootstrap/app.php file.

To subscribe to an event, you may use the Event::listen method:
```
Event::listen(
	'PodcastWasPurchased', 'EmailPurchaseConfirmation@handle'
);
```
Note: You may place these event registrations in a service provider.

When the event is fired, the event object will be passed to the handle method of the listener:
```
class EmailPurchaseConfirmation {

public function handle(PodcastWasPurchased $event)
	{
		//
	}

}
```
Of course, you are free to place your event and listener classes wherever you want in your application, such as an app/Events directory.

Firing An Event
Now we are ready to fire our event using the Event facade:
```
$response = Event::fire(new PodcastWasPurchased($podcast));
```
The fire method returns an array of responses that you can use to control what happens next in your application.

You may also use the event helper to fire an event:
```
event(new PodcastWasPurchased($podcast));
```
Closure Listeners
You can even listen to events without creating a separate handler class at all. For example, in the register method of a service provider, you could do the following:
```
Event::listen('App\Events\PodcastWasPurchased', function($event) {
	// Handle the event...
});
```
Stopping The Propagation Of An Event
Sometimes, you may wish to stop the propagation of an event to other listeners. You may do so using by returning false from your handler:
```
Event::listen('App\Events\PodcastWasPurchased', function($event) {
	// Handle the event...

return false;
});
```
Queued Event Handlers
If you would like your event listener to be queued, you may mark it with the Illuminate\Contracts\Queue\ShouldBeQueued interface:
```
use Illuminate\Contracts\Queue\ShouldBeQueued;

class SendPurchaseConfirmation implements ShouldBeQueued {

public function (PurchasePodcast $event)
	{
		//
	}

}
```
That's it! Now when this listener is called for an event, it will be queued automatically by the event dispatcher.

Note: Of course, you will need to configure your queue settings before using this feature.

If no exceptions are thrown when the handler is executed by the queue, the queued job will be deleted automatically after it has processed. If you need to access the queued job's delete and release methods manually, you may do so. The Illuminate\Queue\InteractsWithQueue trait, which is included by default on queued handlers, gives you access to these methods:
```
public function handle(PodcastWasPurchased $event)
{
	if (true) {
		$this->release(30);
	}
}
```