Update – for folks who learn best visually, I’ve posted a follow-up screencast of the demo steps discussed below, as a DevNuggets video. You can view the video here.
If you’re just getting started with ASP.NET MVC, you may have heard of something called action filters, but haven’t had the chance to use them yet. Action filters provide a convenient mechanism for attaching code to your controllers and/or action methods that implements what are referred to as cross-cutting concerns, that is, functionality that isn’t specific to one particular action method, but rather is something you’d want to re-use across multiple actions.
An action filter is a .NET class that inherits from FilterAttribute or one of its subclasses, usually ActionFilterAttribute, which adds the OnActionExecuting, OnActionExecuted, OnResultExecuting, and OnResultExecuted methods, providing hooks for code to be executed both before and after the action and result are processed.