Processor

The processor is a kind of event bus listener that can execute actions on certain events. A process can be for example used to send an email when a profile has been created:

use Patchlevel\EventSourcing\EventBus\Listener;
use Patchlevel\EventSourcing\EventBus\Message;

final class SendEmailListener implements Listener
{
    private Mailer $mailer;

    private function __construct(Mailer $mailer) 
    {
        $this->mailer = $mailer;
    }

    public function __invoke(Message $message): void
    {
        $event = $message->event();

        if (!$event instanceof ProfileCreated) {
            return;
        }

        $this->mailer->send(
            $event->email(),
            'Profile created',
            '...'
        );
    }
}

Warning

If you only want to listen to certain events, then you have to check it in the __invoke method.