ASMX web services routing in ASP.NET Web Forms

Question

NOTE: There is no MVC in this code. Pure old Web Forms and .asmx Web Service.

I have inherited a large scale ASP.NET Web Forms & Web Service (.asmx) application at my new company.

Due to some need I am trying to do URL Routing for all Web Forms, which I was successfully able to do.

Now for .asmx, routes.MapPageRoute does not work. Based on the below article, I created an IRouteHandler class. Here's how the code looks:

using System;
using System.Web;
using System.Web.Routing;
using System.Web.Services.Protocols;
using System.Collections.Generic;
public class ServiceRouteHandler : IRouteHandler
{
private readonly string _virtualPath;
private readonly WebServiceHandlerFactory _handlerFactory = new WebServiceHandlerFactory();

public ServiceRouteHandler(string virtualPath)
{
    if (virtualPath == null)
        throw new ArgumentNullException("virtualPath");
    if (!virtualPath.StartsWith("~/"))
        throw new ArgumentException("Virtual path must start with ~/", "virtualPath");
    _virtualPath = virtualPath;
}

public IHttpHandler GetHttpHandler(RequestContext requestContext)
{
    // Note: can't pass requestContext.HttpContext as the first parameter because that's
    // type HttpContextBase, while GetHandler wants HttpContext.
    return _handlerFactory.GetHandler(HttpContext.Current, requestContext.HttpContext.Request.HttpMethod, _virtualPath, requestContext.HttpContext.Server.MapPath(_virtualPath));
}

}

http://mikeoncode.blogspot.in/2014/09/aspnet-web-forms-routing-for-web.html

Now when I do routing via Global.asax, it work for the root documentation file but does not work with the Web Methods inside my .asmx files.

 routes.Add("myservice", new System.Web.Routing.Route("service/sDxcdfG3SC", new System.Web.Routing.RouteValueDictionary() { { "controller", null }, { "action", null } }, new ServiceRouteHandler("~/service/myoriginal.asmx")));

    routes.MapPageRoute("", "service/sDxcdfG3SC", "~/service/myoriginal.asmx");

Goal

I would like to map an .asmx Web Method URL such as www.website.com/service/myservice.asmx/fetchdata to a URL with obscured names in it like www.website.com/service/ldfdsfsdf/dsd3dfd3d using .NET Routing.

How can this be done?

Answer 1

It is slightly more tricky to do this with routing than in the article you posted because you don't want the incoming URL to have a query string parameter and it looks like the WebServiceHandler won't call the method without an ?op=Method parameter.

So, there are a few parts to this:

1. A custom route (ServiceRoute) to do URL rewriting to add the ?op=Method parameter
2. An IRouteHandler to wrap the WebServiceHandlerFactory that calls the web service.
3. A set of extension methods to make registration easy.

ServiceRoute

public class ServiceRoute : Route
{
    public ServiceRoute(string url, string virtualPath, RouteValueDictionary defaults, RouteValueDictionary constraints)
        : base(url, defaults, constraints, new ServiceRouteHandler(virtualPath))
    {
        this.VirtualPath = virtualPath;
    }

    public string VirtualPath { get; private set; }

    public override RouteData GetRouteData(HttpContextBase httpContext)
    {
        // Run a test to see if the URL and constraints don't match
        // (will be null) and reject the request if they don't.
        if (base.GetRouteData(httpContext) == null)
            return null;

        // Use URL rewriting to fake the query string for the ASMX
        httpContext.RewritePath(this.VirtualPath);

        return base.GetRouteData(httpContext);
    }
}

ServiceHandler

public class ServiceRouteHandler : IRouteHandler
{
    private readonly string virtualPath;
    private readonly WebServiceHandlerFactory handlerFactory = new WebServiceHandlerFactory();

    public ServiceRouteHandler(string virtualPath)
    {
        if (virtualPath == null)
            throw new ArgumentNullException(nameof(virtualPath));
        if (!virtualPath.StartsWith("~/"))
            throw new ArgumentException("Virtual path must start with ~/", "virtualPath");
        this.virtualPath = virtualPath;
    }

    public IHttpHandler GetHttpHandler(RequestContext requestContext)
    {
        // Strip the query string (if any) off of the file path
        string filePath = virtualPath;
        int qIndex = filePath.IndexOf('?');
        if (qIndex >= 0)
            filePath = filePath.Substring(0, qIndex);

        // Note: can't pass requestContext.HttpContext as the first 
        // parameter because that's type HttpContextBase, while 
        // GetHandler expects HttpContext.
        return handlerFactory.GetHandler(
            HttpContext.Current, 
            requestContext.HttpContext.Request.HttpMethod,
            virtualPath, 
            requestContext.HttpContext.Server.MapPath(filePath));
    }
}

RouteCollectionExtensions

public static class RouteCollectionExtensions
{
    public static void MapServiceRoutes(
        this RouteCollection routes,
        Dictionary<string, string> urlToVirtualPathMap,
        object defaults = null,
        object constraints = null)
    {
        foreach (var kvp in urlToVirtualPathMap)
            MapServiceRoute(routes, null, kvp.Key, kvp.Value, defaults, constraints);
    }

    public static Route MapServiceRoute(
        this RouteCollection routes, 
        string url, 
        string virtualPath, 
        object defaults = null, 
        object constraints = null)
    {
        return MapServiceRoute(routes, null, url, virtualPath, defaults, constraints);
    }

    public static Route MapServiceRoute(
        this RouteCollection routes, 
        string routeName, 
        string url, 
        string virtualPath, 
        object defaults = null, 
        object constraints = null)
    {
        if (routes == null)
            throw new ArgumentNullException("routes");

        Route route = new ServiceRoute(
            url: url,
            virtualPath: virtualPath,
            defaults: new RouteValueDictionary(defaults) { { "controller", null }, { "action", null } },
            constraints: new RouteValueDictionary(constraints)
        );
        routes.Add(routeName, route);
        return route;
    }
}

Usage

You can either use MapServiceRoute to add the routes one at a time (with an optional name):

public static class RouteConfig
{
    public static void RegisterRoutes(RouteCollection routes)
    {
        var settings = new FriendlyUrlSettings();
        settings.AutoRedirectMode = RedirectMode.Permanent;
        routes.EnableFriendlyUrls(settings);

        routes.MapServiceRoute("AddRoute", "service/ldfdsfsdf/dsd3dfd3d", "~/service/myoriginal.asmx?op=Add");
        routes.MapServiceRoute("SubtractRoute", "service/ldfdsfsdf/dsd3dfd3g", "~/service/myoriginal.asmx?op=Subtract");
        routes.MapServiceRoute("MultiplyRoute", "service/ldfdsfsdf/dsd3dfd3k", "~/service/myoriginal.asmx?op=Multiply");
        routes.MapServiceRoute("DivideRoute", "service/ldfdsfsdf/dsd3dfd3v", "~/service/myoriginal.asmx?op=Divide");
    }
}

Alternatively, you can call MapServiceRoutes to map a batch of your web service routes at once:

public static class RouteConfig
{
    public static void RegisterRoutes(RouteCollection routes)
    {
        var settings = new FriendlyUrlSettings();
        settings.AutoRedirectMode = RedirectMode.Permanent;
        routes.EnableFriendlyUrls(settings);

        routes.MapServiceRoutes(new Dictionary<string, string>
        {
            { "service/ldfdsfsdf/dsd3dfd3d", "~/service/myoriginal.asmx?op=Add" },
            { "service/ldfdsfsdf/dsd3dfd3g", "~/service/myoriginal.asmx?op=Subtract" },
            { "service/ldfdsfsdf/dsd3dfd3k", "~/service/myoriginal.asmx?op=Multiply" },
            { "service/ldfdsfsdf/dsd3dfd3v", "~/service/myoriginal.asmx?op=Divide" },
        });
    }
}

NOTE: If you were to have MVC in the application, you should generally register your MVC routes after these routes.

References:

• Creating a route for a .asmx Web Service with ASP.NET routing
• .NET 4 URL Routing for Web Services (asmx)