In this tutorial I’ll tell you how you can do it in pure javascript. Surfing web, I stumbled upon the Google Feed API, and thought that perhaps he would help me in this matter. Because using this service, I can easily (on-fly) to convert XML (of RSS) to JSON format. And as far as we know, javascript can easily work with JSON response. That’s what we will use, and now, lets check online demo.
index.html
<html>main.css
<head>
<title>New own RSS reader demonstration</title>
<link rel="stylesheet" type="text/css" href="css/main.css" />
<script type="text/javascript" src="js/main.js"></script>
</head>
<body>
<div>
<div id="post_results1" rss_num="8" rss_url="http://rss.news.yahoo.com/rss/topstories">
<div>
<img alt="Loading..." src="images/loading.gif" />
</div>
</div>
<div id="post_results2" rss_num="8" rss_url="http://newsrss.bbc.co.uk/rss/newsonline_world_edition/front_page/rss.xml">
<div>
<img alt="Loading..." src="images/loading.gif" />
</div>
</div>
<div style="clear:both;"></div>
</div>
<div style="bottom:0;position:fixed;">
<hr style="clear:both;" />
<h4>
<a href="http://techdilute.com/create-rss-reader/">back to original article page</a>
</h4>
</div>
</body>
</html>
body{background:#eee;margin:0;padding:0}main.js
.example{background:#FFF;width:825px;border:1px #000 solid;margin:20px auto;padding:15px;-moz-border-radius: 3px;-webkit-border-radius: 3px}
.post_results {
margin: 5px;
width: 400px;
border:1px solid #444;
float:left;
}
.post_results ul {
list-style:none;
text-align:left;
padding:0;
margin: 0;
}
.post_results ul li {
background: #555555;
background: -moz-linear-gradient(top, #555555 0%, #444444 100%); /* FF3.6+ */
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#555555), color-stop(100%,#444444)); /* Chrome,Safari4+ */
background: -webkit-linear-gradient(top, #555555 0%,#444444 100%); /* Chrome10+,Safari5.1+ */
background: -o-linear-gradient(top, #555555 0%,#444444 100%); /* Opera11.10+ */
background: -ms-linear-gradient(top, #555555 0%,#444444 100%); /* IE10+ */
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#555555', endColorstr='#444444',GradientType=0 ); /* IE6-9 */
background: linear-gradient(top, #555555 0%,#444444 100%); /* W3C */
height: 60px;
padding: 10px;
}
.post_results ul li:hover{
background: #666;
}
.post_results ul li a{
color: #fff;
display: block;
font-size: 14px;
font-weight: bold;
text-align: center;
text-decoration: none;
margin-bottom:5px;
}
.post_results ul li a:hover{
color: #eee;
}
.post_results ul li p {
color: #ddd;
font-size: 13px;
margin: 0;
}
function myGetElementsByClassName(selector) {As you can see in index.html– I prepared two DIV elements where going to load RSS feeds, in attributes (rss_url and rss_num) I pointing url of rss feed and amount of elements which going to display and It is rather simple.
if ( document.getElementsByClassName ) {
return document.getElementsByClassName(selector);
}
var returnList = new Array();
var nodes = document.getElementsByTagName('div');
var max = nodes.length;
for ( var i = 0; i < max; i++ ) {
if ( nodes[i].className == selector ) {
returnList[returnList.length] = nodes[i];
}
}
return returnList;
}
var rssReader = {
containers : null,
// initialization function
init : function(selector) {
containers = myGetElementsByClassName(selector);
for(i=0;i<containers.length;i++){
// getting necessary variables
var rssUrl = containers[i].getAttribute('rss_url');
var num = containers[i].getAttribute('rss_num');
var id = containers[i].getAttribute('id');
// creating temp scripts which will help us to transform XML (RSS) to JSON
var url = encodeURIComponent(rssUrl);
var googUrl = 'https://ajax.googleapis.com/ajax/services/feed/load?v=1.0&num='+num+'&q='+url+'&callback=rssReader.parse&context='+id;
var script = document.createElement('script');
script.setAttribute('type','text/javascript');
script.setAttribute('charset','utf-8');
script.setAttribute('src',googUrl);
containers[i].appendChild(script);
}
},
// parsing of results by google
parse : function(context, data) {
var container = document.getElementById(context);
container.innerHTML = '';
// creating list of elements
var mainList = document.createElement('ul');
// also creating its childs (subitems)
var entries = data.feed.entries;
for (var i=0; i<entries.length; i++) {
var listItem = document.createElement('li');
var title = entries[i].title;
var contentSnippet = entries[i].contentSnippet;
var contentSnippetText = document.createTextNode(contentSnippet);
var link = document.createElement('a');
link.setAttribute('href', entries[i].link);
link.setAttribute('target','_blank');
var text = document.createTextNode(title);
link.appendChild(text);
// add link to list item
listItem.appendChild(link);
var desc = document.createElement('p');
desc.appendChild(contentSnippetText);
// add description to list item
listItem.appendChild(desc);
// adding list item to main list
mainList.appendChild(listItem);
}
container.appendChild(mainList);
}
};
window.onload = function() {
rssReader.init('post_results');
}
When the page loads – I appending prepared javascript objects into our containers (div). That javascript asking google to convers RSS(XML) feed to JSON format using Google Feed API. After, script pass executing to ‘parse’ function of our object, that function convert JSON date into HTML presentation. So, in result – it loading our XML feed in HTML format. All pretty nice
