<?php
/** 
* File contains just the base class
*
* @package classes
* @copyright Copyright 2003-2009 Zen Cart Development Team
* @license http://www.zen-cart.com/license/2_0.txt GNU Public License V2.0
* @version $Id: class.base.php 14535 2009-10-07 22:16:19Z wilt $
*/
/**
* abstract class base
*
* any class that wants to notify or listen for events must extend this base class
*
* @package classes
*/
class base {
/**
* method used to an attach an observer to the notifier object
* 
* NB. We have to get a little sneaky here to stop session based classes adding events ad infinitum
* To do this we first concatenate the class name with the event id, as a class is only ever going to attach to an
* event id once, this provides a unigue key. To ensure there are no naming problems with the array key, we md5 the unique
* name to provide a unique hashed key. 
* 
* @param object Reference to the observer class
* @param array An array of eventId's to observe
*/
function attach(&$observer, $eventIDArray) {
foreach($eventIDArray as $eventID) {
$nameHash = md5(get_class($observer).$eventID);
base::setStaticObserver($nameHash, array('obs'=>&$observer, 'eventID'=>$eventID));
}
}
/**
* method used to detach an observer from the notifier object
* @param object
* @param array
*/
function detach($observer, $eventIDArray) {
foreach($eventIDArray as $eventID) {    
$nameHash = md5(get_class($observer).$eventID);
base::unsetStaticObserver($nameHash);
}
}
/**
* method to notify observers that an event as occurred in the notifier object
* 
* @param string The event ID to notify for
* @param array paramters to pass to the observer, useful for passing stuff which is outside of the 'scope' of the observed class.
*/
function notify($eventID, $paramArray = array()) {
$observers = & base::getStaticObserver();
if (!is_null($observers))
{
foreach($observers as $key=>$obs) {
if ($obs['eventID'] == $eventID) {
$obs['obs']->update($this, $eventID, $paramArray);
}
}
}
}
function & getStaticProperty($var)
{
static $staticProperty;
return $staticProperty;
}
function & getStaticObserver() {
return base::getStaticProperty('observer');
}
function & setStaticObserver($element, $value)
{
$observer =  & base::getStaticObserver();
$observer[$element] = $value;
}
function & unsetStaticObserver($element)
{
$observer =  & base::getStaticObserver();
unset($observer[$element]);
}
}