Example
use Symfony\Component\EventDispatcher\EventDispatcher;
use Symfony\Component\EventDispatcher\Event;
use Symfony\Component\EventDispatcher\GenericEvent;
// you may store this in a dependency injection container for use as a service
$dispatcher = new EventDispatcher();
// you can attach listeners to specific events directly with any callable
$dispatcher->addListener('an.event.occurred', function(Event $event) {
// process $event
});
// somewhere in your system, an event happens
$data = // some important object
$event = new GenericEvent($data, ['more' => 'event information']);
// dispatch the event
// our listener on "an.event.occurred" above will be called with $event
// we could attach many more listeners to this event, and they too would be called
$dispatcher->dispatch('an.event.occurred', $event);
