Invoke ASP.NET MVC Controller When Requesting .html file

I need to add some new life to a legacy application :)

I'd like to call an MVC controller when a "static" HTML page is requested in order to add some markup to the page before returning it to the client.

I tried to follow the approach found in this thread: How to read web.config settings in .html page?

...but even though I have this route defined:

routes.MapRoute(
    name: "Topic", 
    url: "html/{fileName}.html", 
    defaults: new { controller = "Topic", action = "Index" });

the controller is not being called. I have my web.config defined with:

<remove name="WebServiceHandlerFactory-Integrated" />
<add name="HTML" path="*.html" verb="*" 
    type="System.Web.UI.PageHandlerFactory" 
    resourceType="File" preCondition="integratedMode" />

I suspect that I need to call something else besides the PageHandlerFactory or perhaps the issue is something entirely different.

UPDATE: My dev environment is working with integrated pipeline mode, but I need to check if my production environment will support it.

Solution

If you do this:

routes.RouteExistingFiles = true;

You should find this works - even without the handler addition. In the controller you can load the HTML directly using the HostingEnvironment.VirtualPathProvider's GetFile method and do something with it - or better still just use a normal MVC view that renders the same content as the static file, just with your additions.

Although be aware that this means any files that are potentially caught by any routes will be pushed into the MVC pipeline. This isn't generally a concern, however, if decent separation of routes and physical paths is used.