Working With Rails

There’s a bit of magic going on there, but basically when Rails is about to call the filter it does a series of checks fo see if the supplied filter is a Symbol, String, Proc, or Method, and then does the appropriate thing with each case.

I.e. in case of Symbol it calls the method named in the symbol, in case of String it evaluates the string etc..

Now since in your example the result doesn’t match any of the above cases the final check Rails does is to see if the supplied argument responds to “filter”, and if so it will then call the “filter” method on the supplied object.

Now CASClient::Frameworks::Rails::Filter is a Module which actually contains the class method “filter”. So when Rails asks “respons_to?(:filter)” it will return true, and Rails will then call that method…neat, eh? :)

The relevant magic bit is the “evaluate_method” defined in active_support/callbacks.rb:
callbacks.rb on GitHub

Hope it helps..

Controller filters can be either the name of a method, a block, or in this case, a class that responds to a “filter” method. When invoked, the filter method is passed the instance of whichever controller you’ve declared it in.

For additional information, see the docs here: ActionController::Filters

wow what a wonderful explanation… Thanx a lot. In fact it’s weired at the first instance to understand by looking the code. But these magics can be understood very well after such kind of explanation…..Bravo

Hey, recommend me if you have the chance ;)