//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");
	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("title","description","pubDate");
		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");
	var tmpElement = null;
	for (var i=0; i<properties.length; i++)
	{
		if (chanElement!=null) {
			tmpElement = chanElement.getElementsByTagName(properties[i])[0];
			if (tmpElement) 
				if (tmpElement!= null)
					eval("this."+properties[i]+"=tmpElement.childNodes[0].nodeValue");
		}
	}
	if (chanElement!=null) {
		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",document.rssform.rssurl.value,true);
	xhr.setRequestHeader("Cache-Control", "no-cache");
	xhr.setRequestHeader("Pragma", "no-cache");
	xhr.onreadystatechange = function() {
		if (xhr.readyState == 4)
		{
			if (xhr.responseText != null)
				processRSS(xhr.responseXML);
		}
	}

	//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)
{
	//default values for html tags used
	var imageTag = "<img id='chan_image'";
	var startItemTag = "<div id='item'>";
	var startTitle = "<div id='item_title' class='updatesTitle'>";
	var startLink = "<div id='item_link'>";
	var startDescription = "<div id='item_description' class='updatesDescription'>";
	var endTag = "</div>";

	//populate channel data
	//var properties = new Array("title","link","description","pubDate","copyright");
	//var properties = new Array("description");
//	for (var i=0; i<properties.length; i++)
//	{
//		eval("document.getElementById('chan_"+properties[i]+"').innerHTML = ''");
//		curProp = eval("RSS."+properties[i]);
//		if (curProp != null)
//			eval("document.getElementById('chan_"+properties[i]+"').innerHTML = curProp");
//	}
	
	//populate the items
	document.getElementById("chan_items").innerHTML = "";

   var maxItems = 5;
   if (RSS.items.length < maxItems) {
      maxItems = RSS.items.length;
   }

	for (var i=0; i<maxItems; i++)
	{
		item_html = startItemTag;
		item_html += (RSS.items[i].title == null) ? "" : startTitle + 
				"<h5>" + getDatePartOnly(RSS.items[i].pubDate) + "</h5>" +
            "<h4><a href='" + RSS.items[i].link + "'>" +
				RSS.items[i].title + "</a></h4>" + endTag;
		item_html += (RSS.items[i].description == null) ? "" : startDescription + "<p>" + RSS.items[i].description + "</p>" + endTag;
		item_html += endTag;
		document.getElementById("chan_items").innerHTML += item_html;
	}

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

function getDatePartOnly(dateTime) {
	if (dateTime != null) {
		var parts = dateTime.split(' ');
		return parts[0] + ' ' + parts[1] + ' ' + parts[2] + ' ' + parts[3];
	} else {
		return '';
	}
}

var xhr;