Question

Just curious, they sound similar. What are the differences between ExecuteCore() vs OnActionExecuting(ActionExecutingContext filterContext)?

In what situations would one be more useful over the other?

Answer 1

Actually, they’re just different points in MVC execution pipeline.

1. ExecuteCore is called by
   MvcHandler after controller itself
   is instantiated. By this moment MVC
   doesn’t even know about how
   controller will invoke its action.
   You can override standard
   Controller’s ExecuteCore to tweak
   its overall execution process a
   little bit.

2. OnActionExecuting is a completely
   different story. It is called during
   action filters invocation by
   ControllerActionInvoker. By that
   point MVC already knows that action
   exists, invokes it, obtains all
   filters (usually defined as
   attributes) and executes it in a
   given moment of overall execution
   pipeline (OnActionExecuting,
   OnActionExecuted, OnResultExecuting
   and so on).

It depends on what exactly you want to achieve when deciding what extension point to use.

• Override ExecuteCore in derived
  Controller to tweak its common
  behavior (not really often the case
  in normal app).
• Use filters to
  perform some additional tasks that
  seem orthogonal to what acion itself
  is supposed to do (often this is some
  AOP-like logic or relates to database session/transaction management).