Simple RSS

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• Download demo application (binaries only) - 13 Kb

What is it?

This article describes a simple RSS reader built on a couple of classes, RSSChannel and RSSItem. For an introduction to , please see this Wikipedia article. You use the reader by selecting a channel, clicking "Update" to retrieve the latest articles, selecting an entry in the article list, and clicking "View" to the view the article. The article is displayed in a new IE window. Click here for an animated view

How it works

The reader is based on a couple of classes, RSSChannel and RSSItem. RSSChannel encapsulates an RSS feed while RSSItem represents individual items in the feed. Retrieving a feed is as easy as constructing an RSSChannel and calling fetchItems().

  // Create the channel and fetch its items
  RSSChannel channel =
    new RSSChannel ("ABC News - International",
                    "http://my.abcnews.go.com/rsspublic/world_rss20.xml");
  channel.fetchItems();

The collection of articles is retrieved via the channel's Items property. Each article is an instance of an RSSItem object and exposes a few commonly used attributes such as the article title, description, URL, author and publication timestamp.

  // Print titles of retrieved articles
  foreach (RSSItem rssItem in channel.Items)
      Console.Writeln (rssItem.Title);

RSSChannel works by downloading and parsing the content made available at the channel URL. All the "heavy lifting" is done by the WebResourceProvider and StringParser classes, described elsewhere at CodeProject.

RSSChannel

RSSChannel works by downloading the content offered by the RSS feed, parsing the XML document, and extracting the channel's title, publication timestamp and collection of items. The base WebResourceProvider class takes care of the task of retrieving the content and calls RSSChannel's parseContent() override, which does the following:

1. Get the <rss> element - fail if none.
2. Get the value of the contained <channel> element - fail if none.
3. Get the value of the contained <title> element - fail if none.
4. Get the value of the optional <pubDate> or <lastBuildDate> element.
5. Construct an RSSItem from every contained <item> element.

RSSChannel exposes the following properties:

Items		Gets the collection of articles (RSSItems) in the channel.
Name		Gets and sets the channel's name.
Title		Gets the channel's title.
Updated		Gets the channel's updated timestamp.

RSSChannel also contains other properties (and methods) inherited from the WebResourceProvider class from which it derives.

RSSItem

RSSItem represents a single item (i.e. article) in the RSSChannel and works by constructing itself from an <item> element present contained within the feed's <channel> element. See this link for a complete list of sub-elements contained within <item>.

RSSItem exposes the following properties:

Author		Gets the article's author.
Description		Gets the article's description.
Link		Gets the article URL.
Published		Gets the article's publication time.
PublishedAsString		Gets the article's publication timestamp as a string.
Title		Gets the article's title.

Revision History

• 15 Jan 2006
  Initial version.