Beginning JavaScript with DOM Scripting and Ajax, 2nd Edition

Chapter 8 ■ Back-End Interaction with Ajax and Node.js
exampleExternalRSS.html (excerpt)
Get Yahoo news
■ ■Note RSS is an acronym for Really Simple Syndication. In essence, it is XML with content in it that you want to share with
the world—typically, news headlines. The specifications for RSS are available at http://blogs.law.harvard.edu/tech/rss,
and you can read more about its benefits at Wikipedia: http://en.wikipedia.org/wiki/RSS.
The important detail in this example is that RSS is a standardized format, and you know the XML structure—even
if you get it from a third-party web site. Every valid RSS document contains—among many other things—an items
element with nested item elements. Each of these contains at least a title describing and a link pointing to the full
piece of information. You can use these to show a list of clickable headlines that send the user to the Yahoo site where
she can read the full news article, as shown in Figure 8-6.
Figure 8-6. Retrieving and showing RSS feed data
The script is once again a simple XHR. The difference is that instead of linking to the URL directly, you pass it to
the PHP script as a GET parameter:
externalRSS.js
readrss = {
doxhr:function( container, url ) {
[... code snipped as it is the same as in the last example ...]
request.open('get', 'loadrss.php?url=' + encodeURI( url ) );
request.setRequestHeader('If-Modified-Since', 'Mon, 12 Jan 2013 00:00:00 GMT' );
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