Chapter 18: RSS and Atom

Overview

"Content is King!"

"Content is everywhere."

"It's all about the content."

It's obvious from these comments that spring up frequently in newsgroups, forums, technical articles, and elsewhere that many people consider content important. However, just what is content and how do you get it in and out of your applications?

Content is the actual information on a Web site-the technical articles, the blog posts, the media files. Content is basically everything on your average Web site except the navigation elements and advertisements.

You share your content with others when they visit your Web site. If the content on your site changes over time, and people want to stay current on that information, they must check your site frequently to see if anything has changed. Different solutions have been proposed to this problem-from push technologies such as PointCast to pull technologies such as CDF (Channel Definition Format), RSS, and Atom. Although push technologies have fallen by the wayside, RSS and Atom are increasing in importance, especially because they are used in Weblogs (blogs), news sites, and podcasting.

Although RSS and Atom are generally thought of in terms of Web sites, they also have importance for non-Web applications. A database or desktop application can provide a feed of updates via RSS or Atom. Client applications can use this feed to stay in sync.

This chapter looks at means of reading and writing these two families of XML formats.