LIS 525 - RSS and News Feeds

News feeds are primarily a method for sharing content dynamically among different Web sites, though individual users may also access them directly using appropriate software.

The provider sets up a properly formatted file, which may be updated either manually or automatically by a script or by specialized software, such as blogging packages. This file contains a short list of news items.

An aggregator site may use a script to collect data from several news sites and reformat the items as HTML. They can then be viewed using a regular Web browser.

As an alternative, a user can run news reader software, such as Awasu, to monitor a number of news sites. Such software may be more or less integrated with the Web browser (Awasu, for example, translates the news feed into HTML and displays it in a browser pane).

In Firefox, you can place the URL for a news feed in a "live bookmark"; items in the feed then appear dynamically as bookmarks within what appears to be a folder.

The most common standard followed is RSS (variously interpreted as Really Simple Syndication, RDF Site Summary, or Rich Site Summary). There are actually two lines of the RSS standard, one based on RDS (Resource Description Standard) and the other on plain XML.

Since RSS is delivered as text via HTTP, it can also be viewed in its raw form by a Web browser (except Opera, which treats it as HTML, and Lynx, which prompts for a download). For example, try this link:

(Internet Explorer may call up the wrong helper application for a local XML file, but should display a properly served file correctly.)

An RSS file should normally have the MIME type text/xml (and hence usually the extension .xml). It should start with an XML declaration, like

<?xml version="1.0" encoding="iso-8859-1" ?>
In the non-RDS case, the rest of the file will consist of an rss element, starting with a tag like
<rss version="2.0">
and ending with
</rss>

The rss element contains a single channel element. Required elements within the channel element are title, link, and description. There are also various optional elements. To be useful as a list of items, the channel element must contain one or more item elements.

Each item element must contain at least a title element or a description element. Of various optional elements within the item element, the link element is needed if the item is intended to point to a resource elsewhere that provides more information than is present in the title or description.

For a very simple example of an RSS file, see 525rss.xml.

A more recent standard is Atom. Atom files are also in XML and look similar to RSS files, but, to be valid, require more elements and are thus a little harder to construct by hand. Use of Atom and information on it are both still rather sparse; but Atom feeds are now available from Google.

For more complex information interchange between businesses, a more general standard, such as ICE (Information and Content Exchange), may be required.

An older method of delivering and receiving news is, of course, newsgroups, which use the NEWS protocol rather than HTTP, and which may or may not be distributed to multiple servers. At the receiving end, these are supported by e-mail clients such as Netscape and Outlook. An example of an aggregation service using this method is Genecast.

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Last updated October 30, 2007.
This page maintained by Prof. Tim Craven
E-mail (text/plain only): craven@uwo.ca
Faculty of Information and Media Studies
University of Western Ontario,
London, Ontario
Canada, N6A 5B7