<?php
	
	/**
	 * Note: 
	 *   1. When adressing variables from submit containing
	 *	 	Prefix_Special as part of their name use
	 *	 	$event->getPrefixSpecial(true) instead of
	 *	 	$event->Prefix_Special as usual. This is due PHP
	 *	 	is converting "." symbols in variable names during
	 *	 	submit info "_". $event->getPrefixSpecial optional
	 *	 	1st parameter returns correct corrent Prefix_Special
	 *	 	for variables beeing submitted such way (e.g. variable
	 *	 	name that will be converted by PHP: "users.read_only_id"
	 *	 	will be submitted as "users_read_only_id".
	 *
	 *	 2.	When using $this->Application-LinkVar on variables submitted
	 *		from form which contain $Prefix_Special then note 1st item. Example:
	 *		LinkVar($event->getPrefixSpecial(true).'_varname',$event->Prefix_Special.'_varname')
	 *
	 */


	/**
	 * Default event handler. Mostly abstract class
	 *
	 */
	class kEventHandler extends kBase {
		
		/**
		 * In case if event should be handled with mehod,
		 * which name differs from event name, then it
		 * should be specified here.
		 * key - event name, value - event method 
		 *
		 * @var Array
		 * @access protected
		 */
		var $eventMethods=Array();
		
		/**
		 * Define alternative event processing method names
		 * 
		 * @see $eventMethods
		 * @access protected
		 */
		function mapEvents()
		{
			
		}
		
		function getPrefixSpecial()
		{
			trigger_error('Usage of getPrefixSpecial() this method is forbidden in kEventHandler class children. Use $event->getPrefixSpecial(true); instead', E_USER_ERROR);
		}
		
		/**
		 * Set's prefix and special
		 *
		 * @param string $prefix
		 * @param string $special
		 * @access public
		 */
		function Init($prefix,$special)
		{
			parent::Init($prefix,$special);
			$this->mapEvents();
		}
		
		/**
		 * Process Event
		 *
		 * @param kEvent $event
		 * @access public
		 */
		function processEvent(&$event)
		{
			$event_name=$event->Name;
			if( isset($this->eventMethods[$event_name]) ) $event_name=$this->eventMethods[$event_name];
			
			if( method_exists($this,$event_name) )
			{
				$this->$event_name($event);
			}
			else 
			{
				trigger_error('event <b>'.$event->Name.'</b> not implemented in class <b>'.get_class($this).'</b>', E_USER_ERROR);
			}
		}
		
		/**
		 * Sample dummy event
		 *
		 * @param kEvent $event
		 * @access protected
		 */
		function OnBuild(&$event)
		{
			/*echo 'building: <br>';
			print_pre($event);*/
		}
		
		/**
		 * Returns to previous template in opener stack
		 *
		 * @param kEvent $event
		 */
		function OnGoBack(&$event)
		{
			$event->SetRedirectParam('opener', 'u');
		}
		
		/**
		 * Apply some special processing to
		 * object beeing recalled before using
		 * it in other events that call prepareObject
		 *
		 * @param Object $object
		 * @param kEvent $event
		 * @access protected
		 */
		function prepareObject(&$object, &$event)
		{
			// processing here
		}
		
		/**
		 * Creates new event as child of
		 * event passed as $event param
		 *
		 * @param kEvent $event
		 * @access protected
		 */
		function &inheritEvent(&$event, $name=null)
		{
			$child_event = new kEvent();
			$child_event->MasterEvent =& $event;
			$child_event->Prefix=$event->Prefix;
			$child_event->Special=$event->Special;
			$child_event->Prefix_Special=$event->Prefix_Special;
			$child_event->Name = $name;
			return $child_event;
		}
	}


?>