RSS - JavaScript implementations

I started my RSS adventures scripting a javascript RSS Reader and posted it on hotscripts as a download. Most people really liked it, despite the fact that javascript doesn't allow you to read remote files in certain browsers.

I feel that it would make a lot more sense doing something like this in a server side language like PHP/C# (which allows it) etc - since rss files are normally remotely hosted, which defeats the purpose if you cant read them remotely.

If you however want to go this route there is always ways to get around this issue, like copying the rss file to the server where the script is running on, or more preferrably making use of a script that acts as a proxy, simply pass your url to the proxy script and return xml from it.(like you'll see below)

<?php
    header ("content-type: text/xml");
    echo file_get_contents($_REQUEST['url']);
?>

<%@ WebHandler Language="C#" Class="rssremote" %>

using System;
using System.Web;
using System.Xml;
using System.IO;

public class rssremote : IHttpHandler {
    
    public void ProcessRequest (HttpContext context) {
        context.Response.ContentType = "text/xml";
        XmlDocument xdoc = new XmlDocument();
        xdoc.Load(context.Request.QueryString["url"]);
        context.Response.Write(xdoc.OuterXml);
    }
 
    public bool IsReusable {
        get {
            return false;
        }
    }
}

<%@ WebHandler Language="VB" Class="rssremote" %>

Imports System
Imports System.Web
Imports System.Xml
Imports System.IO

Public Class rssremote : Implements IHttpHandler
    
    Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
        context.Response.ContentType = "text/xml"
        Dim xdoc As New XmlDocument()
        xdoc.Load(context.Request.QueryString("url"))
        context.Response.Write(xdoc.OuterXml)
    End Sub
 
    Public ReadOnly Property IsReusable() As Boolean Implements IHttpHandler.IsReusable
        Get
            Return False
        End Get
    End Property

End Class

function RSS(url)
{	
    this.items = new Array();

    try
    {
        var xmlDoc = (document.all) ? new ActiveXObject("Microsoft.XMLDOM")
						            : document.implementation.createDocument("","",null);
        xmlDoc.async = false;
        xmlDoc.load('rssremote.php?url=' + escape(url));

        this.title = getElement(xmlDoc, 'title');
        this.link = getElement(xmlDoc, 'link');
        this.description = getElement(xmlDoc, 'description');

        var items = xmlDoc.getElementsByTagName('item');
        for (var i = 0; i < items.length; i++) 
        {
            this.items[i] = new function()
            {
                this.title = getElement(items[i], 'title');
                this.description = getElement(items[i], 'description');
                this.link = getElement(items[i], 'link');
            }
        }
    }	
    catch(e)
    {
        alert(e.message);
    }

    function getElement(parent, tagName)
    {
        return parent.getElementsByTagName(tagName)[0].firstChild.nodeValue;
    }
}

function RSS(url, elementID)
{
    var html = document.getElementById(elementID);
    var xmlhttp = (window.XMLHttpRequest) ? new XMLHttpRequest() : new ActiveXObject("Microsoft.XMLHTTP");
    	
    if (xmlhttp)
    {
        html.innerHTML = '<img src="img/ajax-loader.gif" />';
        xmlhttp.onreadystatechange = function() 
        {	
            if (xmlhttp.readyState==4) 
            {
                var html = document.getElementById(elementID);
                try
                {
                    html.innerHTML =(xmlhttp.status == 200) ? xmlhttp.responseText : "RSS failed to load, error " + xmlhttp.status;
                }
                catch(ex)
                {
                    html.innerHTML = ex.description;
                }
            }
        }
        xmlhttp.open("GET", "php/xmlhttp.php?url="+escape(url),true);
        xmlhttp.send(null);
    }
}

RSS - JavaScript implementations

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