HttpModule only on specific MVC route

Question

I have a custom IHttpModule that I would like to only work on a specific route.

For example : http://example.com/HandleAzureTask

I want this module to only be invoked/handled on the /HandleAzureTask route.

Since this is not a controller, I can't really set the [Authorize] attribute on it; how can I force it only to be invoked/handled if user is authenticated?

I am on ASP.NET MVC 4 and currently have my module added to web.config as such:

<modules>
  <remove name="AzureWebDAVModule" />
  <add name="AzureWebDAVModule" type="VMC.WebDAV.Azure.Module.AzureWebDAVModule, VMC.WebDAV.Azure.Module" />
</modules>

Answer 1

HttpModules are called on every request (HttpHandlers, instead, can be filtered). If you just want to perform your task only on the selected route, you can do the following:

Set up a route like this:

routes.MapRoute(
    name: "AzureWebDAVRoute",
    url: "HandleAzureTask",
    // notice the enableHandler parameter
    defaults: new { controller = "YourController", action = "YourAction", enableHandler = true }
);

On your module:

public class AzureWebDAVModule : IHttpModule
{
    public void Init(HttpApplication context)
    {
        // you can't directly access Request object here, it will throw an exception
        context.PostAcquireRequestState += new EventHandler(context_PostAcquireRequestState);
    }

    void context_PostAcquireRequestState(object sender, EventArgs e)
    {
        HttpApplication context = (HttpApplication)sender;
        RouteData routeData = context.Request.RequestContext.RouteData;

        if (routeData != null && routeData.Values["enableHandler"] != null)
        {
            // do your stuff
        }
    }

    public void Dispose()
    {
        //
    }
}

Now your task will be performed on the selected route only. Please note that you need the parameter since you can't find the current route by name.