Symfony Event Dispatcher Minimal Proof-of-Concept

gistfile1.php

use Symfony\Component\EventDispatcher\EventDispatcher,
    Symfony\Component\EventDispatcher\Event;

class RandomEvent extends Event {
	protected $data;
	public function __construct($data) {
		$this -> data = $data;
	}
	public function getData()
	{
		return $this -> data;
	}
}

$dis = new EventDispatcher;

$dis -> addListener('foo.action', function (RandomEvent $e) {
	// Change something about $e
	$data = $e -> getData();
	$data -> text = 'This text has been changed by the event listener';
});

$myData = new stdclass;
$myData -> text = 'This text as it was orignally';/**/

echo '<p>Before event dispatch: <code>' . print_r($myData, true) . '</code>';
echo '<p>Dispatching event…';

$event = new RandomEvent($myData);
$dis -> dispatch('foo.action', $event);

echo '<p>After event dispatch: <code>' . print_r($myData, true) . '</code>';

output.html

<p>Before event dispatch: <code>stdClass Object
(
    [text] => This text as it was orignally
)
</code><p>Dispatching event…<p>After event dispatch: <code>stdClass Object
(
    [text] => This text has been changed by the event listener
)
</code>