Cook Computing

Implementing an XML-RPC Service with ASP.NET MVC

April 1, 2012 Written by Charles Cook

I received a couple of emails recently asking how to implement an XML-RPC service in an ASP.NET MVC application. In case anyone is interested this is how to do it (this is an expanded version of an earlier post).

Define an interface for your XML-RPC service, for example:

using CookComputing.XmlRpc;

public interface IStateName
{
  [XmlRpcMethod("examples.getStateName")]
  string GetStateName(int stateNumber);
}

Implement the service:

using CookComputing.XmlRpc;

public class StateNameService : XmlRpcService, IStateName
{
  public string GetStateName(int stateNumber)
  {
    if (stateNumber < 1 || stateNumber > m_stateNames.Length)
      throw new XmlRpcFaultException(1, "Invalid state number");
    return m_stateNames[stateNumber - 1];
  }

  string[] m_stateNames
    = { "Alabama", "Alaska", "Arizona", "Arkansas",
        "California", "Colorado", "Connecticut", "Delaware", "Florida",
        "Georgia", "Hawaii", "Idaho", "Illinois", "Indiana", "Iowa", 
        "Kansas", "Kentucky", "Lousiana", "Maine", "Maryland", "Massachusetts",
        "Michigan", "Minnesota", "Mississipi", "Missouri", "Montana",
        "Nebraska", "Nevada", "New Hampshire", "New Jersey", "New Mexico", 
        "New York", "North Carolina", "North Dakota", "Ohio", "Oklahoma",
        "Oregon", "Pennsylviania", "Rhose Island", "South Carolina", 
        "South Dakota", "Tennessee", "Texas", "Utah", "Vermont", "Virginia", 
        "Washington", "West Virginia", "Wisconsin", "Wyoming" };
}

Implement a custom route handler:

using System.Web;
using System.Web.Routing;

public class StateNameRouteHandler : IRouteHandler
{
  public IHttpHandler GetHttpHandler(RequestContext requestContext)
  {
    return new StateNameService();
  }
}

Register the custom route in global.asax.cs:

public static void RegisterRoutes(RouteCollection routes)
{
  routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

  routes.Add(new Route("api/statename", new StateNameRouteHandler()));

  // ...

}

Check that everything is working by pointing your browser to the url for the handler, for example something like http://localhost:33821/api/statename in this case when running from Visual Studio. You should then see an automatically generated help page for the service. If this is ok then point your XML-RPC client to the service and start making calls.