In writing this answer, I was asked if there are guarantees about the behaviour of the ActionFilterAttribute. and I was unable to answer with confidence.
In particular, are all four of the methods OnActionExecuted
, OnActionExecuting
, OnResultExecuted
& OnResultExecuting
guaranteed to be called for all requests that pass through the attribute, or are there circumstances (such as exceptions, dropped connection etc) where one or more of the phases might not fire?
No they are not guaranteed to be called.
Think of the Authorization filters. If authorization fails, would you expect any action filters to run? That could be a big security hole. I believe an exception would also stop the pipeline of filters and only exception filters would be executed from that point.
Given the following filter:
on the following controller action:
Neither the
Index()
method or theOnActionExecuted()
is ever reached becauseOnActionExecuting()
has an exception.