Building the RSS Endpoint with a Repeater Control
To expose the latest news items from the Articles table as a valid RSS 2.0 feed, the simplest path is to let ASP.NET render XML directly. This means the page should output nothing but XML and set its MIME type to text/xml. The page declaration looks like this:
With the content type defined, the framework will skip rendering any master page or layout, ensuring a clean RSS payload. The next step is to fetch the most recent items. A lightweight SQL statement that pulls only the data needed for the feed is efficient:
When the data is ready, a Repeater control is perfect for stitching together the <rss> container, the <channel> wrapper, and a series of <item> nodes. The control’s templates allow us to keep the XML structure readable and maintainable. The page’s markup might resemble this:
The HeaderTemplate and FooterTemplate wrap the entire feed. Within ItemTemplate, the FormatForXML helper cleans any characters that break XML rules - things like ampersands, quotes, and less‑than symbols. The publication date is formatted with the invariant “R” pattern, producing RFC‑1123 compliant timestamps that feed readers expect.
Behind the scenes, the page’s code‑behind is minimal. The Page_Load event opens a connection, runs the query, binds the reader to the repeater, and closes the connection. The helper method looks like this:
Notice the use of using blocks to guarantee that connections are released promptly. The repeater’s data binding pipeline handles the row‑by‑row rendering, so the final output is a clean, well‑formed RSS feed ready for consumption by any RSS reader or aggregator.
Optimizing Performance and Expanding Functionality
Even a straightforward RSS endpoint can become a bottleneck if the volume of traffic grows. A common improvement is output caching: if the feed doesn’t need to change on every request, storing a cached version for a short window reduces database hits dramatically. In ASP.NET, the simplest way to enable caching on a page is to add the @OutputCache directive at the top of the markup:
This instructs the framework to remember the rendered output for 120 seconds, serving the cached payload for any subsequent request. Because the cache lives in memory, the response time is essentially the time it takes to send XML over the network, not to query the database.
Beyond caching, many news sites organize content into categories or tags. Adding a Category column to the Articles table is straightforward and offers a powerful filter for feed consumers. By extending the query to include a WHERE clause driven by a query‑string parameter, the same page can serve multiple feeds - one for each category - without duplicating code. The URL might look like rss.aspx?cat=technology, and the Page_Load method could adapt as follows:
{
string category = Request.QueryString["cat"];
string sql = @"SELECT TOP 5 ArticleID, Title, Author, Description, DatePublished
FROM Articles";
if (!string.IsNullOrEmpty(category))
{
sql += @" WHERE Category = @Category
ORDER BY DatePublished DESC";
}
else
{
sql += @" ORDER BY DatePublished DESC";
}
using (var cmd = new SqlCommand(sql, conn))
{
if (!string.IsNullOrEmpty(category))
cmd.Parameters.AddWithValue("@Category", category);
conn.Open();
rptRSS.DataSource = cmd.ExecuteReader();
rptRSS.DataBind();
}
}
When the cat parameter is present, the query filters to that category; otherwise, it returns the five most recent items across all categories. Because the Repeater logic stays unchanged, the XML output remains valid regardless of the category. Feed readers can now subscribe to rss.aspx?cat=technology to receive only technology news, for instance.
Another performance consideration is database indexing. A composite index on (Category, DatePublished DESC) ensures that the server can quickly locate the newest items for any given category. Without the index, the query planner would resort to scanning the entire table, which scales poorly. Likewise, if the Articles table grows large, consider partitioning it by date or archiving older rows so that the feed query always touches a manageable data set.
Beyond data access, security is a subtle concern. The RSS endpoint must be publicly accessible but should still guard against injection attacks. Parameterizing the Category value, as shown, eliminates the risk of malicious SQL code. Additionally, enabling HTTPS on the site ensures that the feed remains encrypted in transit, protecting the integrity of the content and the privacy of subscribers.
Testing, Deployment, and Author Information
Before publishing the feed, validate it against the RSS 2.0 specification. A quick check can be done with the Google News to ensure that items appear as expected and that the feed updates when new articles are added.
Deployment in IIS is straightforward. Place the rss.aspx page and its code‑behind DLL in the site’s root or a subfolder. Verify that the site has the text/xml MIME type configured; IIS includes it by default, but custom sites may need to add it explicitly. If you’re using integrated pipeline mode, no additional configuration is necessary. For classic mode, ensure that the page runs under ASP.NET by checking the *.aspx file association.
Monitoring the feed’s health is a good habit. Set up logging for failed database connections, unexpected null values, or exceptions thrown during binding. A simple log entry might look like this:
By capturing these errors, you can quickly detect when the feed stops working and address the root cause before subscribers notice a glitch.
Author: 4GuysFromRolla.com. With over five years of experience in Microsoft Web technologies, Scott has contributed to the community through articles, tutorials, and his book ASP.NET Data Web Controls Kick Start (ISBN 0672325012). Follow his updates on his blog at
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