<?php

/*
 * SITE : Classes & PHP
 * TITRE : PHP4 - Design pattern observer
 * AUTEUR : Antoine DESSAIGNE
 *
 */

header('Content-Type: text/plain');

Class Observable
{
	var $name;

	var $_listeners = array();

	function Observable($name)
	{
		$this->name = $name;
	}

	function register($listener)
	{
		if (!is_object($listener) || !is_a($listener, 'Observer'))
			return;

		foreach ($this->_listeners as $el)
			if ($el === $listener)
				return;
		$this->_listeners[] =& $listener;
	}

	function _notify($event)
	{
		foreach ($this->_listeners as $el)
			$el->notify($event);
	}

	function setName($name)
	{
		$this->name = $name;
		$this->_notify('name');
	}
}

Class Observer
{
	var $name;

	function Observer($name)
	{
		$this->__uniqid = uniqid(rand(), true);
		$this->name = $name;
	}

	function notify($event)
	{
		echo "Je m'appelle ".$this->name." et le nom de l'objet observé a changé\n";
	}
}

$observable = new Observable('toto');
echo $observable->name."\n";

$obs1 =& new Observer('obs1');
$obs2 =& new Observer('obs2');
$observable->register($obs1);
$observable->register($obs1);
$observable->register($obs2);
$observable->register($observable);

$observable->setName('titi');
echo $observable->name."\n";

?>