PHP: Events - A module class for handling events

Events.class.php

<?php

/**
 * Event class
 * A module class for handling events
 *
 * @author Stefano Azzolini <lastguest@gmail.com>
 */
class Events {
	/**
	 * The Events <-> Handlers internal register
	 * @static
	 * @var array
	 */
	static private $register = array();

	/**
	 * Register and event handler
	 *
	 * @static
	 * @param  string $event    The event descriptor
	 * @param  callback $callback The callback for the defined handler
	 * @example
	 *     // Register custom handler for "test.event"
	 *      Events::on('test.event',function($a=1,$b=2){
	 *      	echo "Called TEST with (".$a.",".$b.")!\n";
	 *      });
	 */
	static public function on($event,$callback){
		static::$register[$event][] = $callback;
	}

	/**
	 * Remove all handlers for an event
	 *
	 * @static
	 * @param  string $event The event descriptor
	 * @example
	 *     Events::off('data.received');
	 */
	static public function off($event){
		unset (static::$register[$event]);
	}

	/**
	 * Trigger all registered event handlers for a specified event
	 *
	 * @static
	 * @return array The handler results queue
	 * @example
	 *     Events::trigger('test.event',12,'foobar');
	 */
	static public function trigger(){
		$args = func_get_args();
		$event = array_shift($args);
		// No handlers founded
		if(static::$register[$event] == false) return null;
		$results = array();
		// Trigger all handler for the event
		foreach(static::$register[$event] as $handler){
			$results[] = call_user_func_array($handler,$args);
		}
		// Get the result queue
		return $results;
	}

}