/* *******************************************************************
incAJAX.js
Contains the functions for sending and receiving AJAX requests/responses
-scott 6/1/06
******************************************************************** */

// -------------------------------------------------------------------
// Global Request Object and Other Global Variables
// -------------------------------------------------------------------
var gHTTP_Request; 
var gsResponseFunction;
var gsErrorResponseFunction;
var gbDebugAJAX = false;

// -------------------------------------------------------------------
// gfunSendRequest(sURL, sMethod, sPostData, aryHeaderData)
// Sends an AJAX Request to a URL (with optional posted data)
// Parameters:
//	sURL: The URL to send the Request to
//	sMethod: "Get" or "Post"
//	sPostData: String of Name/Value pairs to send with the request
//	aryHeaderData: a 2 Deminsional Array of Header data to send with the request
//	sFunctionName: The function to be called with the response result 
//		sent as a lone parameter
//	bDebug: Set to True to get Alerts for Testing and Debugging
//  sErrorFunctionName: The function to be called with any Error Response
//		sent as paramters: (status, responseText)
//  bIsAsynchronous: Set to false, then the function returns the AJAX Response
//		and the thread halts while waiting for a response.
// -------------------------------------------------------------------
function gfunSendRequest(sURL, sMethod, sPostData, aryHeaderData, sFunctionName, bDebug, sErrorFunctionName, bIsAsynchronous) {
	if (sMethod == null) sMethod = "get";
	if (bDebug == null) bDebug = false;
	if (bIsAsynchronous == null) bIsAsynchronous = true;
	
	var sTemp = "";
	if (gHTTP_Request != null) {
		// A Request is already in progress
		if (aryHeaderData) {
			if (typeof aryHeaderData == "string") {
				sTemp = aryHeaderData;
			}
			else  {
				// Change the Headers array to a string name value pairs so that it can be passed.
				for (var i = 0; i < aryHeaderData.length; i++) {
					sTemp = aryHeaderData[i][0] + "=" + aryHeaderData[i][1] + "&";
				}
				sTemp = sTemp.substring(0,sTemp.length-2);
			}
		}
		// Wait 0.1 seconds and try the request again
		if (bIsAsynchronous) setTimeout("gfunSendRequest('" + sURL + "', '" + sMethod + "', '" + sPostData + "', '" + sTemp + "', '" + sFunctionName + "', " + bDebug + ", '" + sErrorFunctionName + "', " + bIsAsynchronous + ");",100);
		return;
	}

    // Add a QueryString to prevent Caching in IE
    if (document.all) {
	    var dDate = new Date();
	    sURL = sURL + ((sURL.indexOf("?") <= 0) ? "?" : "&") + "random=" + dDate.getTime();
    }
    
	if (window.XMLHttpRequest) { // Mozilla, Safari,... 
		gHTTP_Request = new XMLHttpRequest();
	}
	else if (window.ActiveXObject) { // IE 
		try {
			gHTTP_Request = new ActiveXObject("Microsoft.XMLHTTP"); 
		}
		catch (e) {
			return false;
		}
	} 
	
	if (bIsAsynchronous) gHTTP_Request.onreadystatechange = gfunLoadExternalData; 
	gHTTP_Request.open(sMethod, sURL, bIsAsynchronous); 
	if (sMethod.toLowerCase() == "post") gHTTP_Request.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
	if (typeof aryHeaderData == "string") {
		if (aryHeaderData.length > 0) {
			// Build the Header Array from a string of name/Value pairs (Querystring format)
			sTemp = aryHeaderData;
			aryHeaderData = new Array();
			var i = 0;
			while (sTemp.length > 0) {
				aryHeaderData[i] = new Array();
				aryHeaderData[i][0] = sTemp.substring(0,sTemp.indexOf("="));
				if (sTemp.indexOf("&") > 0) {
					aryHeaderData[i][1] = sTemp.substring(sTemp.indexOf("=")+1,sTemp.indexOf("&"));
					sTemp = sTemp.substr(sTemp.indexOf("&")+1);
				}
				else {
					aryHeaderData[i][1] = sTemp.substr(sTemp.indexOf("=")+1);
					sTemp = "";
				}
								
				i++;
			}
		}
		else {
			aryHeaderData = null;
		}
	}
	
	if (aryHeaderData) {
		for (var i = 0; i < aryHeaderData.length; i++) {
			gHTTP_Request.setRequestHeader(aryHeaderData[i][0], aryHeaderData[i][1])
		}
	}
	gsResponseFunction = sFunctionName;
	gsErrorResponseFunction = sErrorFunctionName;
	if (bDebug != null) gbDebugAJAX = bDebug;
	gHTTP_Request.send(sPostData);
	if (bIsAsynchronous) return true;
	else {
		var sReturnString = (window.location.href.indexOf("http") == -1 || gHTTP_Request.status==200) ? gHTTP_Request.responseText : gHTTP_Request.status;
		gHTTP_Request = null;
		return sReturnString;
	}
}


// -------------------------------------------------------------------
// gfunLoadExternalData()
// Called when the AJAX request object's ready state changes
//		Uses the sFunctionName sent in the call to gfunSendRequest to
//		handle the response text.
// -------------------------------------------------------------------
function gfunLoadExternalData() { 
	if (gHTTP_Request.readyState == 4) {
		var sText = gHTTP_Request.responseText;
		if (gHTTP_Request.status == 200 && gsResponseFunction != null) {
			eval(gsResponseFunction + "(gHTTP_Request.responseText);");
			//eval(gsResponseFunction + "(\"" + sText.replace(/\"/gi,"\\\"") + "\")");
		}
		else if (gsErrorResponseFunction != null && gsErrorResponseFunction.length > 0) {
			eval(gsErrorResponseFunction + "(gHTTP_Request.status, gHTTP_Request.responseText);");
		}
		if (gbDebugAJAX) {
			alert("gHTTP_Request.status: " + gHTTP_Request.status);
			alert("gHTTP_Request.responseText:\r\n");
			while (sText.length > 0) {
				alert(sText.substr(0, 500));
				sText = sText.substr(500);
			}
			gbDebugAJAX = false;
		}
		gHTTP_Request = null;
	}
}


// -------------------------------------------------------------------
// gfunParseAjaxValue()
// Used to get data from AJAX response text split into separate variables
// NOTE: By the default, the sData should be formatted:
//		|var|VariableName1|var|VariableValue1|var|VariableName2|var|VariableValue2|var|
// -------------------------------------------------------------------

function gfunParseAjaxValue(sData, sVarName, sDelimiter) {
	if (sDelimiter == null) sDelimiter = "|var|";
	
	var sSearchString = sDelimiter + sVarName + sDelimiter;
	var sValue = "";
	
	var nPos = sData.indexOf(sSearchString);
	var nNextPos;
	
	if (nPos >= 0) {
		nPos = nPos + sSearchString.length;
		nNextPos = sData.indexOf(sDelimiter,nPos);
		if (nNextPos == -1) nNextPos = sData.length; // Last Variable, so get until the end of the string
		sValue = sData.substring(nPos, nNextPos);
	}
	
	return sValue;
}