Question

I have a piece of code that is needed in 2 of my controllers, but not all of them. Where does this method belong?
I have read about helpers, but those seem to be for view-related code. Someone proposed the lib-folder, but that seems ‘too far away’ from the controller logic, i don’t need it in views or models.
Has someone experience with that sort of problem?

Answer 1

There are three options, the easiest (though, the most unclean) is the application controller. The other two options are a shared parent controller

class FooController < FooBarParentController
   # code here  
end

class BarController < FooBarParentController
   # code here  
end

Usage depends on how related these controllers are.

The final solution is a module

module FooBarModule
  extend ActiveSupport::Concern

  included do
    # class level code
    # before_filter ....
  end

  module ClassMethods
    # all class methods here
  end

  # instance methods here
end

This is where the shared code required is for a handful of ad-hoc controllers, or if you are already using the inheritance above and this code doesn’t quite fit into this subset (thus attempting to emulate multiple inheritance).