Suggestion: to extract AC filter methods

Suggestion: to extract AbstractController::Callbacks::ClassMethods (maybe to ActiveSupport). Mechanism ‘before/after/around’ isn’t connected with controllers only. Is it? Why not to consider it with ActiveSupport::Callbacks? It will make a possibility to do your own events for ‘before/after/around’ wrapping… Not only controller’s actions…

You can already use ActiveSupport::Callbacks for this. I think the documentation for this class is thorough and should give you a good understand of how it works.