//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 properties = new Array("title", "link", "description", "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("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");
//	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
    var rssurl = document.getElementById("rssUrl");
	
	xhr.open("GET", rssurl.value,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)
{
//	//default values for html tags used
    var startItemTag = "<div id='item' style='font-weight:bold;margin:0 8px 2px 0;text-align:justify;'>";
    var startDescription = "<div id='item_description' style='font-weight:normal;color: #422121;margin: 0 8px 8px 0px;text-align:justify;'>";
	var endTag = "</div>";

	//populate the items
	document.getElementById("chan_items").innerHTML = "";
//	for (var i = 0; i < RSS.items.length; i++)
	for (var i = 0; i < 3; i++)
	{
	    item_html = startItemTag;
	    var pubDate = getLocalDate(RSS.items[i].pubDate);
	    item_html += "[" + pubDate + "]&nbsp;";
	    if (RSS.items[i].link != null) {
	        item_html += "<a href=\"";
	        item_html += RSS.items[i].link;
	        item_html += "\" target=\"_blank\">";
	    }
	    var title = new String(RSS.items[i].title);
	    item_html += title;
	    
	    if (RSS.items[i].link != null) {
	        item_html += "</a>";
	    }
	    item_html += endTag;

        if (RSS.items[i].description != null)
        {
            var description = new String(RSS.items[i].description);
            if (description.length > 90) {
                description = description.substr(0, 87) + "...";
	        }
	        item_html += (RSS.items[i].description == null) ? "" : startDescription + description + endTag;
	    }

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

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

var xhr;