How do I get ASP.NET WebForms Routing to route .asmx JSON calls properly?

Question

I am attempting to implement multi-tenancy in a legacy ASP.NET WebForms app. I want the URL to indicate the proper client, like so:

http://example.com/client_name/Default.aspx
http://example.com/client_name/MyWebService.asmx

However, I cannot get it to route the .asmx's properly. This routing rule picks up all incoming urls just fine:

routes.Add("ClientSelector", new System.Web.Routing.Route
(
   "{client}/{*path}",
   routeHandler: new ClientRoute()
));

But I am having issues with handling .asmx calls. Here's my IRouteHandler, below. The error I get is:

A first chance exception of type 'System.Web.Services.Protocols.SoapException' occurred in System.Web.Services.dll

Additional information: Unable to handle request without a valid action parameter. Please supply a valid soap action.

It's supposed to be JSON, but for some reason it's not working. I am setting the content-type - if I send this same exact request without routing, it works fine.

public class ClientRoute : System.Web.Routing.IRouteHandler
{
    private string m_Path;
    private string m_Client;

    public ClientRoute() { }
    public bool IsReusable { get { return true; } }

    public IHttpHandler GetHttpHandler(System.Web.Routing.RequestContext requestContext)
    {
        this.m_Path = (string)requestContext.RouteData.Values["path"];
        this.m_Client = (string)requestContext.RouteData.Values["client"];

        string virtualPath = "~/" + this.m_Path;

        bool shouldValidate = false;

        if (shouldValidate && !UrlAuthorizationModule.CheckUrlAccessForPrincipal(
            virtualPath, requestContext.HttpContext.User,
                          requestContext.HttpContext.Request.HttpMethod))
        {
            requestContext.HttpContext.Response.StatusCode = (int)HttpStatusCode.Unauthorized;
            requestContext.HttpContext.Response.End();
            return null;
        }
        else
        {
            HttpContext.Current.RewritePath(virtualPath);
            HttpContext.Current.Items.Add("Client", this.m_Client);

            if (virtualPath.EndsWith(".aspx"))
                return (IHttpHandler)BuildManager.CreateInstanceFromVirtualPath(virtualPath, typeof(Page));
            else
            {
                var asmxPos = virtualPath.IndexOf(".asmx", StringComparison.OrdinalIgnoreCase);
                if (asmxPos >= 0)
                {
                    // What goes here?  This isn't working...
                    var asmxOnlyVirtualPath = virtualPath.Substring(0, asmxPos + 5);
                    return new System.Web.Services.Protocols.WebServiceHandlerFactory().GetHandler(
                        HttpContext.Current, HttpContext.Current.Request.HttpMethod, asmxOnlyVirtualPath, HttpContext.Current.Server.MapPath(asmxOnlyVirtualPath));
                }
                else
                    return new StaticRoute();
            }
        }
    }
}

Relevant links:

• Getting ScriptHandlerFactory handler

Answer 1

The open source http://www.teamlab.com project is built with ASP.NET Webforms, and uses a multitenant/saas model. I noticed you posted another question inquiring about multitenancy.

Perhaps you can look into their code for reference ideas.