//Copyright (c) 2005 Allan Spartacus Mangune, allan@lexysoft.com, http://www.ajaxgear.com

//Permission is hereby granted, free of charge, to any person 
//obtaining a copy of this software and associated documentation 
//files (the "Software"), to deal in the Software without restriction, 
//including without limitation the rights to use, copy, modify, merge, 
//publish, distribute, sublicense, and/or sell copies of the Software, 
//and to permit persons to whom the Software is furnished to do so, 
//subject to the following conditions:

//The above copyright notice and this permission notice shall be included 
//in all copies or substantial portions of the Software.

//THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
//EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 
//MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
//IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
//DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 
//ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE 
//OR OTHER DEALINGS IN THE SOFTWARE.

function AjaxWrapper()
{
    // Private members
    var _objXmlHttp;
		var _objXslDoc;
		var _bIsXslLoaded 			= false;
    var _strResponseText 		= "";
    var _objResponseXml;
		var _strMethod 					= "GET";
    var _bIsAsynchronous 		= true;
    var _strRequestData 		= "";
		var _strErrorText				= "";
    var _objThis 						= this;
    var _strDestinationPath = "";
    var _bIsXml 						= false;
    var _bIsMozilla 				= false;
		
    // Properties
    
    //Gets the method to be invoked.
    this.getMethod = function () { return _strMethod; }
		
		this.getErrorText = function () { return _strErrorText; }
		
		// Returns flag indicating whether or not xsl is loaded
		this.getIsXslLoaded = function() { return _bIsXslLoaded; }
		
		//Sets the method to be invoked.
    this.setMethod = function (inparam) { _strMethod = inparam; }
    
		//Gets a value that indicates whether or not the call is asynchronous.
    this.getIsAsynchronous = function () { return _bIsAsynchronous; }
    
		//Sets a value that indicates whether or not the call is asynchronous.
    this.setIsAsynchronous = function (inparam) { _bIsAsynchronous = inparam; }
    
		//Gets the query string of the post method.
    this.getRequestData = function () { return _strRequestData;}
    
		//Sets the query string of the post method.
    this.setRequestData = function (inparam) { _strRequestData = inparam;}
    
		//Gets the text reponse of the server.   
    this.getResponseText = function () { return _strResponseText; }
    
		//Gets the text reponse of the server.   
    this.getResponseXml = function () { return _objResponseXml; }
    
		//Sets the URL we are posting/getting to
    this.setDestinationPath = function (inparam) { _strDestinationPath = inparam; }

		//Sets the URL we are posting/getting to
    this.getDestinationPath = function () { return _strDestinationPath; }
    
		//Will the response be xml?
    this.setIsXml = function (inparam) { _bIsXml = inparam; }
    
    // Events
    this.onRequestComplete = function () {};
		
		this.onRequestError = function () {};
    
    // Methods
		this.refreshObject = function () {
			_strRequestData = "";
			_objResponseXml = null;
			_strResponseText = "";
			_strDestinationPath = "";
			
		}
		
		this.appendRequestData = function ( strKey, strVal ) {
				if( _strRequestData.length > 0 ) {
					_strRequestData += "&";
				}
				
				_strRequestData += strKey;
				_strRequestData += "=";
				_strRequestData += strVal;
		}
		
		// Starts the request to server.
    this.startRequest = function(){
        CreateXMLHttpRequest();
        if ( _strMethod.toUpperCase() == "GET" ){
            SendGetRequest();
        }
        else if (_strMethod.toUpperCase() == "POST"){
            SendPostRequest();
        }    
	   	
			_objXmlHttp.onreadystatechange = HandleServerResponse;	
		}
	
	
		// Sends a get request.
		function SendGetRequest()
		{
				var strAmpersand = "&";
				if ( _strRequestData == "" ) {
					strAmpersand = "";
				}
				
				_objXmlHttp.open( _strMethod, _strDestinationPath + "?" + _strRequestData + strAmpersand + CreateTimestamp(), _bIsAsynchronous );
				
				if ( _bIsXml )
				{
						//if (_bIsMozilla) _objXmlHttp.overrideMimeType('text/xml');
						_objXmlHttp.setRequestHeader( "Content-Type", "text/xml" );
				}
				
				_objXmlHttp.send( null );
		}
	
		// Sends a post request.
		function SendPostRequest()
		{
				_objXmlHttp.open( _strMethod, _strDestinationPath + "?" + CreateTimestamp() , _bIsAsynchronous );
				_objXmlHttp.setRequestHeader( "Content-Type", "application/x-www-form-urlencoded" );
					
					if ( _bIsXml )
					{
							_objXmlHttp.setRequestHeader( "Content-Type", "text/xml" );
					}
					
					_objXmlHttp.send( _strRequestData );
		}
	
		// Creates a timestamp for querystring.
		function CreateTimestamp()
		{
				return "timestamp=" + new Date().getTime().toString();
		}
	
		
		// Creates the XMLHttpRequest object.
		function CreateXMLHttpRequest (){
				
				if ( window.ActiveXObject ){
					 _objXmlHttp = new ActiveXObject( "Microsoft.XMLHTTP" );
					
							if ( _objXmlHttp ==  null ){
									_objXmlHttp = new ActiveXObject ( "Msxml2.XMLHTTP" );            
							}
					}
					
					else if ( window.XMLHttpRequest ){
							_objXmlHttp = new XMLHttpRequest();
							_bIsMozilla = true;
							
							if ( _objXmlHttp.overrideMimeType ) {
									_objXmlHttp.overrideMimeType( "text/xml" );
							}
					}
					
					else{
							alert("The XMLHttpRequest nor ActiveXObject object could not be created.");
				 }
				 
			 }
		 
		 // Instantiate dom object and load up xsl file - occurs asynchronously
		 this.loadXslt = function( strPath ) {
				CreateXslt();
				
				if( _objXslDoc != null ) {
					_objXslDoc.load( strPath );
				}
			}
		 
		 // Runs our response xml through xsl file, assuming it has been loaded
		 this.transformResponseXml = function() {
			 var objOutputHtml;
			 
			 if( _bIsXslLoaded ) {
				 	if ( window.XSLTProcessor )
					{
						 // support Mozilla/Gecko based browsers
						 var xsltProcessor = new XSLTProcessor();
						 
						 xsltProcessor.importStylesheet( _objXslDoc );
						 objOutputHtml = xsltProcessor.transformToFragment( _objResponseXml, document );
					}
					else if(window.ActiveXObject)
					{
						// support Windows/ActiveX enabled browsers
						objOutputHtml = _objResponseXml.transformNode( _objXslDoc );
					}
					else {
						alert( "Browser does not support ActiveXObject or XSLTProcessor." );
					}
					
				}
			
				return objOutputHtml;
		 }
		 
		 // Creates the XMLHttpRequest object.
    function CreateXslt (){
				if ( window.XSLTProcessor )
				{
						 // support Mozilla/Gecko based browsers
						 _objXslDoc = document.implementation.createDocument( "", "", null );
						 _objXslDoc.addEventListener( "load", FlagIsXslLoaded, false );
				}
				else if( window.ActiveXObject )
				{
						// support Windows / ActiveX
						_objXslDoc = new ActiveXObject( "Microsoft.XMLDOM" );
						_objXslDoc.ondataavailable = FlagIsXslLoaded;
				}
				else{ }
     }
		 
		 function FlagIsXslLoaded() {
				 _bIsXslLoaded = true;
		}
       
    // Handles server's response
    function HandleServerResponse(){
        if( _objXmlHttp.readyState == 4 ){
						
						if( _objXmlHttp.status == 200 ){
								//alert(_objXmlHttp.responseXML.parseError.errorCode);
                _strResponseText 	= _objXmlHttp.responseText;							
                _objResponseXml 	= _objXmlHttp.responseXML;
								_objThis.onRequestComplete();
						}
						else {
							_strErrorText = "Communication error.  Status Code: " + _objXmlHttp.status;
							_objThis.onRequestError();
						}
        }
    }
		
}