MVC Web .Net: Intercept all calls before reaching controller?

Question

I have a .Net MVC web application (Not WebAPI), and I want to intercept all calls to the web app before they reach the controller, check for a value in the request headers, and do something if the value isn't present (such as presenting a 404). What's the ideal way to do this? Keep in mind this is not a Web API application, just a simple web application.

Answer 1

Depending on what specifically you want to do, you could use a default controller which all other controllers extend. That way you can override OnActionExecuting or Initialize and do your check there.

public class ApplicationController : Controller
{
    protected override void OnActionExecuting(ActionExecutingContext filterContext)
    {
        //do your stuff here
    }
}

public class YourController : ApplicationController
{

}

Answer 2

You're looking for global action filters.

Create a class that inherits ActionFilterAttribute, override OnActionExecuting() to perform your processing, and add an instances to global filter collection in Global.asax.cs (inside RegisterGlobalFilters())