/**
 * XMLLoader
 *
 * XMLLoader class loads and validates an XML file.
 * If you loads a text file encoded in the euc-kr encoding via an URLLoader, frequently, the source data is currupted.
 * To avoid this problem, parses the loaded data into an XMLDocument,
 * then, parses the first node of the XMLDocument into an XML.
 * If an error has been occured, reloads the XML data.
 * 
 *
 * @author: Han Sanghun (http://hangunsworld.com, hanguns@gmail.com)
 * @created: 2008 02 28
 * @last modified: 2008 02 29
 */
 
 
package com.hangunsworld.as3.net{
 
	import	flash.events.*;
	import	flash.net.*;
	import	flash.utils.Timer;
	import	flash.xml.*;
 
 
	public class XMLLoader{
 
 
		private var path:String;
		private var returnFunction:Function;
		private var errorFunction:Function;
 
		private var timer:Timer;
		private var xml:XML;
 
		private var xml_ul:URLLoader;
		private var xml_ur:URLRequest;
		private var xml_uv:URLVariables;
 
		/**
		 * XMLLoader constructor
		 *
		 * @param pPath A path of an XML file
		 * @param okFunc A function to call when the XML is loaded successfully
		 * @param errorFunc A function to call when an IOError has occured
		 */
		public function XMLLoader(pPath:String, okFunc:Function=null, errorFunc:Function=null){
 
			path = pPath;
			returnFunction = okFunc;
			errorFunction = errorFunc
 
			XML.ignoreWhitespace = true;
			XML.ignoreComments = true;
 
 
			// Initializes NET objects
			xml_ul = new URLLoader();
			xml_ul.addEventListener (Event.COMPLETE, xmlCompleteListener);
			xml_ul.addEventListener (IOErrorEvent.IO_ERROR, errorListener);
 
			xml_ur = new URLRequest();
			xml_ur.url = path;
 
			xml_uv = new URLVariables();
 
 
			// Initializes Timer object
			timer = new Timer(50, 1);
			timer.addEventListener(TimerEvent.TIMER, timerListener);
 
			timer.start();
 
 
		}// end constructor
 
 
		/**
		 * Timer EventListener
		 * Loads an XML file after some time
		 */
		private function timerListener(evt:TimerEvent):void{
			loadXML();
		}// end timerListener
 
 
		/**
		 * Loads an XML file
		 */
		private function loadXML():void{
 
			if(path.indexOf("?") >= 0){
				// If the url already contains parameters, attaches the random seed to the end of the url
				xml_ur.url = path + "&randomSeed=" + Math.floor(Math.random() * 1000000);
			}else{
				// If the url does not contain parameters, uses an URLVariable object
				xml_uv.randomSeed = Math.floor(Math.random() * 1000000);
				xml_ur.data = xml_uv;
			}
 
			xml_ul.load (xml_ur);
 
		}// end loadXML
 
 
		/**
		 * XML Complete EventListener
		 */
		private function xmlCompleteListener(evt:Event):void{
 
			// Sets the defualt parse state to false
			var parsed:Boolean = false;
 
			var str:String = evt.target.data;
 
			var xmldoc:XMLDocument = new XMLDocument();
			xmldoc.ignoreWhite = true;
 
			try{
 
				// Parses the loaded data into an XMLDocument
				xmldoc.parseXML(str);
 
				// Gets a string from the first node of the XMLDocument
				str = xmldoc.firstChild.toString();
 
				// Parses the string into an XML
				xml = new XML(str);
 
				// If no error has occured, sets the parse stae to true
				parsed = true;
 
			}catch(e){
 
				// If an error occured, loads the XML again
				timer.start();
 
			}// end try catch
 
 
			// If the parse process done without errors and the returnFunction is NOT null, returns the XML data
			if(parsed){
				if(returnFunction != null){
					returnFunction(xml);
				}
			}
 
 
		}// end xmlCompleteListener
 
		/**
		 * XML IOError EventListener
		 */
		private function errorListener(evt:IOErrorEvent):void{
 
			if(errorFunction != null){
				errorFunction(evt);
			}
 
		}// end xmlErrorListener
 
 
	}// end class
 
}// end package

import	com.hangunsworld.as3.net.XMLLoader;
 
var xloader:XMLLoader;
xloader = new XMLLoader(xmlPath, xmlLoaded, xmlErrorListener);
 
function xmlLoaded(xx:XML):void{
	// xml loaded
}
 
function xmlErrorListener(evt:IOErrorEvent):void{
	trace("xml load error");
}