How to create a new event in Symfony?

@arnoldo.moen 

To create a new event in Symfony, you can follow these steps:

1. Define the event class: Create a new class that extends the SymfonyComponentEventDispatcherEvent class. This class will define the event and its properties. For example:

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namespace AppEvent;

use SymfonyComponentEventDispatcherEvent;

class NewEvent extends Event
{
    const NAME = 'new.event';

    private $data;

    public function __construct($data)
    {
        $this->data = $data;
    }

    public function getData()
    {
        return $this->data;
    }
}

1. Register the event: To register the event, you can use the SymfonyComponentEventDispatcherEventDispatcherInterface class. In your service configuration file (e.g. services.yaml), add a new service with the tag "event_dispatcher.event_subscriber" and pass the EventDispatcherInterface object as an argument.

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services:
    AppEventListenerMyListener:
        tags:
            - { name: kernel.event_listener, event: 'new.event', method: onNewEvent }

1. Trigger the event: To trigger the event, you can use the SymfonyComponentEventDispatcherEventDispatcherInterface class. Create a new instance of your event class and pass it to the dispatch method of the EventDispatcherInterface object.

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$event = new NewEvent($data);
$dispatcher->dispatch(NewEvent::NAME, $event);

1. Create event listeners: Create one or more event listeners to handle the event. An event listener is a PHP class that contains a method that is executed when the event is triggered.

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namespace AppEventListener;

use AppEventNewEvent;

class MyListener
{
    public function onNewEvent(NewEvent $event)
    {
        // Do something with the event data
        $data = $event->getData();
    }
}

By following these steps, you can create a new event in Symfony and handle it using event listeners.