Registering for RSS Notifications

Userland has created a simple xml-rpc endpoint that a program can use to register to receive RSS file-change notifications.  Here is a Windows console app (written in C# to run in the .NET framework) that makes an xml-rpc call to that endpoint and echoes the response message to the console.  I called the file RegisterRssCallback.cs.

using System;
using System.Net;
using System.IO;
 
namespace RegisterRssCallback
{
   class RegisterRssCallbackClass
   {
      static void Main(string[] args)
      {
         String requestString;
         HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create("http://radio.xmlstoragesystem.com/RPC2");
 
         requestString = "<?xml version=\"1.0"?>n";
         requestString += "<methodCall>\n";
         requestString += " <methodName>xmlStorageSystem.rssPleaseNotify</methodName>\n";
         requestString += " <params>\n";
         requestString += "  <param>\n";
         requestString += "   <value>RssHasChanged</value>\n";
         requestString += "  </param>\n";
         requestString += "  <param>\n";
         requestString += "   <value><i4>80</i4></value>\n";
         requestString += "  </param>\n";
         requestString += "  <param>\n";
         requestString += "   <value>/HandlerTest/handler.aspx</value>\n";
         requestString += "  </param>\n";
         requestString += "  <param>\n";
         requestString += "   <value>xml-rpc</value>\n";
         requestString += "  </param>\n";
         requestString += "  <param>\n";
         requestString += "   <value><array>\n";
         requestString += "    <data>\n";
         requestString += "     <value>http://radio.weblogs.com/0105476/categories/testing/rss.xml</value>\n";
         requestString += "    </data>\n";
         requestString += "   </array></value>\n";
         requestString += "  </param>\n";
         requestString += " </params>\n";
         requestString += "</methodCall>\n";
         
         myRequest.Method = "POST";
         myRequest.ContentType = "text/xml";
 
         myRequest.ContentLength = requestString.Length;
         Stream outboundStream = myRequest.GetRequestStream();
         StreamWriter w = new StreamWriter(outboundStream);
         w.Write(requestString);
         w.Flush();
         w.Close();
         outboundStream.Close();
 
         // Return the response. 
         WebResponse myResponse = myRequest.GetResponse();
         Stream myResponseStream = myResponse.GetResponseStream();
         StreamReader r = new StreamReader(myResponseStream);
         String s = r.ReadToEnd();
         Console.WriteLine(s);
         
         // Close the response to free resources.
         myResponse.Close();
      }
   }
}

This program can be built with the command:

to create RegisterRssCallback.exe.

The xml-rpc call says that there is an xml-rpc endpoint called RssHasChanged on port 80 of the same server that is making the call at the url http:///HandlerTest/handler.aspx"; It is asking for notification of changes to http://radio.weblogs.com/0105476/categories/testing/rss.xml; I created a new category called testing on my Radio site, so I could force changes to the rss.xml file without changing my Radio home page.

I knew to send this request to the method xmlStorageSystem.rssPleaseNotify at http://radio.xmlstoragesystem.com/RPC2 because I could see this XML fragment in the RSS file:

<cloud
   domain="radio.xmlstoragesystem.com"
   port="80"
   path="/RPC2"
   registerProcedure="xmlStorageSystem.rssPleaseNotify"
   protocol=XML-RPC />

To see the code I wrote to receive the xml-rpc notifications, check out this story.

© Copyright 2003 Jim Klopfenstein. Last update: 2/10/2003; 8:43:43 AM.