PubSub PoC

PubSub.class.php

<?php

$_NL2BR = TRUE;


// more: http://baylorrae.com/php-pubsub/

class PubSub {

	private static $events = array(); // all subscriptions

	// Don't allow PubSub to be initialized outside this class
	private function __construct () { }
	private function __clone () { }

	/**
	 * Adds a subscription to the stack
	 *
	 * @param string   $name
	 * @param function $callback needs to be callable with call_user_func()
	 * @return void
	 * @author Baylor Rae'
	 */
	public static function subscribe ($name, $callback) {
		// Make sure the subscription isn't null
		if (empty(self::$events[$name])) {
			self::$events[$name] = array();
		}

		// push the $callback onto the subscription stack
		array_push(self::$events[$name], $callback);
	}

	/**
	 * Calls the last subscription in the stack
	 *
	 * @param string $name
	 * @param string $params
	 * @return false if fails
	 * @author Baylor Rae'
	 */
	public static function publish ($name, $params = '') {

		// Check to see if the subscribe isn't null
		if (empty(self::$events[$name])) {
			return false;
		}


		// Gets all parameters passed to the function
		// and removes the first, which is $name
		$params = func_get_args();
		array_shift($params);


		$results = array();
		// Loop through all the events and call them
		foreach (self::$events[$name] as $event) {
			if (is_callable($event)) {
				$results[$event] = call_user_func_array($event, $params);
			} elseif (is_callable($event. "::fire")) {
				$results[$event] = call_user_func_array($event . "::fire", $params);
			}
		}

		return $results;
	}

	public static function unsubscribe($name) {
		if (!empty(self::$events[$name])) {
			unset(self::$events[$name]);
		}
	}

}


class Event {
	public static $init;

	public static function init ($subscriptions = "") {
		$class = get_called_class();

		if (!is_array(self::$init)) {
			self::$init = array();
		}

		if (!isset(self::$init[$class])) {
			self::$init[$class] = FALSE;
		}

		if (self::$init[$class] == TRUE) {
			return;
		}

		self::$init[$class] = TRUE;

		if (!empty($subscriptions)) {
			foreach ($subscriptions as $sub) {
				PubSub::subscribe($sub->event, $sub->routine);
			}
		}

	}

	public static function makeHandler ($eventName, $routine) {
		$event = new stdClass();
		$event->event = $eventName;
		$event->routine = $routine;
		return $event;
	}

}


class beforeEventEvent extends Event {

	public static function fire () {
		echo get_class() . "::fire\n";
		return 'fire';
	}


	public static function firealt () {
		echo get_class() . "::firealt\n";
		return 'firealt';
	}


	public static function init ($subscriptions = "") {
		$events = array();
		$events[] = Event::makeHandler('beforeEvent', 'beforeEventEvent::firealt');
		$events[] = Event::makeHandler('beforeEvent', 'beforeEventEvent');


		if (!empty($subscriptions)) {
			foreach ($subscriptions as $sub) {
				$events[] = $sub;
			}
		}

		parent::init($events);
	}
}


class afterEventEvent extends Event {

	public static function fire () {
		echo get_class() . "::fire\n";	
		return 'firealt';
	}

	public static function init ($subscriptions = "") {
		$events = array();
		$events[] = Event::makeHandler('afterEvent', 'afterEventEvent');


		if (!empty($subscriptions)) {
			foreach ($subscriptions as $sub) {
				$events[] = $sub;
			}
		}

		parent::init($events);
	}
}

beforeEventEvent::init();
afterEventEvent::init();

ob_start();
// Basic usage
$results = array();
$results['beforeEvent'] = PubSub::publish('beforeEvent');
echo "...Event...\n";
$results['afterEvent'] = PubSub::publish('afterEvent');

echo "\tRound 1:\n";
print_r($results);

PubSub::unsubscribe('beforeEvent');
PubSub::unsubscribe('afterEvent');

$results = array();
$results['beforeEvent'] = PubSub::publish('beforeEvent');
echo "...Event...\n";
$results['afterEvent'] = PubSub::publish('afterEvent');

echo "\tRound 2:\n";
print_r($results);
$ob = ob_get_clean();
if ($_NL2BR) {
	$buffer = str_replace("\n", "<br />\n", $ob);
} else {
	$buffer = $ob;
}
echo $buffer;