Ajaxion - Standalone AJAX - Part 2 of 2 - C# and Java Example

function Ajaxion(defaultUrl)
{
	// Members
	var request = null;
	var currentEventId = null;
	var allowedEventIdsCsv = null;
	var param = null;

	// Expose Methods
	this.post = post;
	this.postUrl = postUrl;
	this.get = get;
	this.getUrl = getUrl;
	this.parseEventParam = parseEventParam;
	this.showStatus = showStatus;
	this.showStatusImg = showStatusImg;
	this.setEventMonior = setEventMonior;
	this.getParam = getParam;
	this.getResponseString = getResponseString;
	this.getResponseXml = getResponseXml;
	this.getRequest = getRequest;
	this.isEventConsumed = isEventConsumed;
	this.beginEvent = beginEvent;
	this.endEvent = endEvent;

	// Exposed Methods

	function post(eventId, callbackConsumer)
	{
		callUrl("POST", defaultUrl, eventId, callbackConsumer);
	}
	function postUrl(url, eventId, callbackConsumer)
	{
		callUrl("POST", url, eventId, callbackConsumer);
	}

	function get(eventId, callbackConsumer)
	{
		callUrl("GET", defaultUrl, eventId, callbackConsumer);
	}
	function getUrl(url, eventId, callbackConsumer)
	{
		callUrl("GET", url, eventId, callbackConsumer);
	}

	function parseEventParam(eventId)
	{
		return null;
	}
	function getParam()
	{
		if (param != null)
			return param;
		else
			return "";
	}
	function getRequest()
	{
		return request;
	}
	function getResponseString()
	{
		if (request.responseText != null)
			return request.responseText;
		else
			return "";
	}
	function getResponseXml()
	{
		return request.responseXML;
	}
	function setEventMonior(currEventId, currAllowedEventIdsCsv)
	{
		currentEventId = currEventId;
		allowedEventIdsCsv = currAllowedEventIdsCsv;
	}
	function showStatus(elementId, text, backgroundColor)
	{
		window.document.getElementById(elementId).innerHTML = text;
		window.document.getElementById(elementId).style.backgroundColor = backgroundColor;
	}
	function showStatusImg(elementId, imageUrl)
	{
		window.document.getElementById(elementId).src = imageUrl;
	}
	function isEventConsumed()
	{
		return (request.readyState == 4 || request.readyState == "complete");
	}
	function beginEvent(eventId)
	{
		this.setEventMonior(eventId, null);
	}
	function endEvent()
	{
		this.setEventMonior(null, null);
	}
	
	// Internal Methods

	function callUrl(postOrGet, url, eventId, callbackConsumer)
	{
		try
		{
			param = null;
			if (currentEventId == null || isAllowedEventId(eventId))
			{
				request = getXmlHttpRequest();
				if (request != null)
				{
					currentEventId = eventId;
					request.onreadystatechange = callbackConsumer;
					param = this.parseEventParam(eventId);
					var ajaxUrl = initAjaxCallUrl(url, eventId, param);
					var asynchronous = true;
					request.open(postOrGet, ajaxUrl, asynchronous);
					if (postOrGet == "POST")
						request.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
					request.send(null);
				}
				else alert("Can not create XMLHttpRequest object...");
			}
			else alert("Please wait, " + currentEventId + " is currently runing...");
		}
		catch (ex)
		{
			alert("callUrl exception: " + ex.description);
		}
	}
	function getXmlHttpRequest()
	{
		var xmlHttpReq;
		try
		{
			if (window.XMLHttpRequest != null) // For IE7 and Mozilla browsers
				xmlHttpReq = new XMLHttpRequest();
			else if (window.ActiveXObject) // for IE 5.0 and IE 6.0 browsers
			{
				try
				{
					xmlHttpReq = new ActiveXObject("Microsoft.XMLHTTP");
				}
				catch (msEx)
				{
					xmlHttpReq = new ActiveXObject("Msxml2.XMLHTTP");
				}
			}
		}
		catch (ex)
		{
			alert("getXmlHttpRequest exception: " + ex.description);
			xmlHttpReq = null;
		}
		return xmlHttpReq;
	}
	function initAjaxCallUrl(url, eventId, params)
	{
		var urlEventId = "e";
		var urlParam = "p";
		var urlDate = "d";

		var ajaxUrlParams =
			urlEventId + "=" + eventId
			+ (params != null ? "&" + urlParam + "=" + params : "")
			+ "&" + urlDate + "=" + new Date().toUTCString();

		if (url.indexOf("?") == -1)
			return url + "?" + ajaxUrlParams;
		else
			return url + "&" + ajaxUrlParams;
	}
	function isAllowedEventId(eventId)
	{
		if (allowedEventIdsCsv == null || eventId.length > allowedEventIdsCsv.length)
			return false;
		else if (eventId == allowedEventIdsCsv)
			return true;
		else if (allowedEventIdsCsv.indexOf("," + eventId + ",") > 0)
			return true;
		else if (allowedEventIdsCsv.indexOf(eventId + ",") == 0)
			return true;
		else if (allowedEventIdsCsv.indexOf("," + eventId) > 0)
			return true;
		else
			return false;
	}
}