var xhr;
var noRSSFeedsToDisplay = 5;



//OBJECTS

//objects inside the RSS2Item object
function RSS2Enclosure(encElement)
{
	if (encElement == null)
	{
		this.url = null;
		this.length = null;
		this.type = null;
	}
	else
	{
		this.url = encElement.getAttribute("url");
		this.length = encElement.getAttribute("length");
		this.type = encElement.getAttribute("type");
	}
}

function RSS2Guid(guidElement)
{
	if (guidElement == null)
	{
		this.isPermaLink = null;
		this.value = null;
	}
	else
	{
		this.isPermaLink = guidElement.getAttribute("isPermaLink");
		this.value = guidElement.childNodes[0].nodeValue;
	}
}

function RSS2Source(souElement)
{
	if (souElement == null)
	{
		this.url = null;
		this.value = null;
	}
	else
	{
		this.url = souElement.getAttribute("url");
		this.value = souElement.childNodes[0].nodeValue;
	}
}




//object containing the RSS 2.0 item
function RSS2Item(itemxml)
{
	//required
	this.title;
	this.link;
	this.description;

	//optional vars
	this.author;
	this.comments;
	this.pubDate;

	//optional objects
	this.category;
	this.enclosure;
	this.guid;
	this.source;

	var properties = new Array("title", "link", "description", "author", "comments", "pubDate", "category");
	var tmpElement = null;
	for (var i=0; i<properties.length; i++)
	{
		tmpElement = itemxml.getElementsByTagName(properties[i])[0];
		if (tmpElement != null)
			eval("this."+properties[i]+"=tmpElement.childNodes[0].nodeValue");
	}

	//this.category = new RSS2Category(itemxml.getElementsByTagName("category")[0]);
	this.enclosure = new RSS2Enclosure(itemxml.getElementsByTagName("enclosure")[0]);
	this.guid = new RSS2Guid(itemxml.getElementsByTagName("guid")[0]);
	this.source = new RSS2Source(itemxml.getElementsByTagName("source")[0]);
}

//objects inside the RSS2Channel object
function RSS2Category(catElement)
{
	if (catElement == null)
	{
		this.domain = null;
		this.value = null;
	}
	else
	{
		this.domain = catElement.getAttribute("domain");
		this.value = catElement.childNodes[0].nodeValue;
	}
}

//object containing RSS image tag info
function RSS2Image(imgElement)
{
	if (imgElement == null)
	{
	this.url = null;
	this.link = null;
	this.width = null;
	this.height = null;
	this.description = null;
	}
	else
	{
		imgAttribs = new Array("url","title","link","width","height","description");
		for (var i=0; i<imgAttribs.length; i++)
			if (imgElement.getAttribute(imgAttribs[i]) != null)
				eval("this."+imgAttribs[i]+"=imgElement.getAttribute("+imgAttribs[i]+")");
	}
}




//object containing the parsed RSS 2.0 channel
function RSS2Channel(rssxml)
{
//required
this.title;
this.link;
this.description;

//array of RSS2Item objects
this.items = new Array();

//optional vars
this.language;
this.copyright;
this.managingEditor;
this.webMaster;
this.pubDate;
this.lastBuildDate;
this.generator;
this.docs;
this.ttl;
this.rating;

//optional objects
this.category;
this.image;

var chanElement = rssxml.getElementsByTagName("channel")[0];
var itemElements = rssxml.getElementsByTagName("item");

for (var i=0; i<itemElements.length; i++)
	{
	Item = new RSS2Item(itemElements[i]);
	this.items.push(Item);
	//chanElement.removeChild(itemElements[i]);
	}

var properties = new Array("title", "link", "description", "language", "copyright", "managingEditor", "webMaster", "pubDate", "lastBuildDate", "generator", "docs", "ttl", "rating", "category" );
var tmpElement = null;
for (var i=0; i<properties.length; i++)
	{
	tmpElement = chanElement.getElementsByTagName(properties[i])[0];
	if (tmpElement!= null)
		{
		eval("this."+properties[i]+"=tmpElement.childNodes[0].nodeValue");
		}
	}
// this.category = new RSS2Category(chanElement.getElementsByTagName("category")[0]);
this.image = new RSS2Image(chanElement.getElementsByTagName("image")[0]);
}

//PROCESSES

//uses xmlhttpreq to get the raw rss xml
function getRSS()
{
	//call the right constructor for the browser being used
	if (window.ActiveXObject)
		xhr = new ActiveXObject("Microsoft.XMLHTTP");
	else if (window.XMLHttpRequest)
		xhr = new XMLHttpRequest();
	else
		alert("not supported");

	//prepare the xmlhttprequest object
	xhr.open("GET", "http://www.gmretiree.com/wordpress/?feed=rss2" ,true);
	xhr.setRequestHeader("Cache-Control", "no-cache");
	xhr.setRequestHeader("Pragma", "no-cache");
	xhr.onreadystatechange = function() {
		if (xhr.readyState == 4)
		{
			if (xhr.status == 200)
			{
				if (xhr.responseText != null)
					processRSS(xhr.responseXML);
				else
				{
					alert("Failed to receive RSS file from the server - file not found.");
					return false;
				}
			}
			else
				alert("Error code " + xhr.status + " received: " + xhr.statusText);
		}
	}

	//send the request
	xhr.send(null);
}

//processes the received rss xml
function processRSS(rssxml)
{
	RSS = new RSS2Channel(rssxml);
	showRSS(RSS);
}




//shows the RSS content in the browser
function showRSS(RSS)
{
document.getElementById("chan_items").innerHTML = "";

for (var i=0; (i < RSS.items.length) && (i < noRSSFeedsToDisplay ); i++)
	{
	item_html = "<div id='item'>";
	if( RSS.items[i].category != null )	item_html += "<h3 class=ItemCategory>"+  RSS.items[i].category +"</h3>";
	if( RSS.items[i].title != null )	item_html += "<a href=\""+ RSS.items[i].link +"\"><h3 class=ItemTitle>"  +  RSS.items[i].title + "</h3></a>";
	if( RSS.items[i].description != null )	item_html += "<h3 class=ItemDesc>" + RSS.items[i].description + "&nbsp;&nbsp;&nbsp;<a href=\""+ RSS.items[i].link +"\">more ...</a></h3>";		
	item_html += "</div><br/>";

	document.getElementById("chan_items").innerHTML += item_html;
	}


//document.getElementById("chan").style.visibility = "visible";
return true;
}