Laravel 5: Triggering Events With event

The event helper function is a convenient way to dispatch a particular $event to its listeners. An optional $payload of data can also be supplied when dispatching the event. When the event is dispatched, all its listeners will be called and any responses from the listener will be added to an array. The array of responses is generally the return value of the event function.

The event helper function can also be used to dispatch object based events without having to resolve the event dispatcher dependency.

#Signature

The signature of the event function is:

1function event(
2    $eventObject
3);
4 
5function event(
6    $event,
7    $payload = [],
8    $halt = false
9);

#Example Use

The following examples will highlight the various ways to use the event function:

 1/**
 2 * The following code is simply creating a new event class
 3 * to signal that a video was watched.
 4 */
 5 
 6namespace App\Events;
 7 
 8use App\Video;
 9use App\Events\Event;
10use Illuminate\Queue\SerializesModels;
11 
12class VideoWasWatched extends Event
13{
14    use SerializesModels;
15 
16    public $video;
17 
18    /**
19     * Create a new event instance.
20     *
21     * @param  Video  $video
22     * @return void
23     */
24    public function __construct(Video $video)
25    {
26        $this->video = $video;
27    }
28}

An event can be fired by the name of a class like so:

1event(\App\Events\VideoWasWatched::class, $video);

Alternatively, an event can be fired by instantiating a new instance of the event class itself:

1event(new VideoWasWatched($video));

In the above example, a $payloadwas not supplied. This is because the event instance itself will become the payload. It is equivalent to the following:

1$event = new VideoWasWatched($video);
2event('App\Events\VideoWasWatched', $event);

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