rails_action_args.rb

module AbstractController
  class Base
  private
    # Modification of abstract controllers process action to take and
    # pass on any arguments to "send_action" (currently alias for "send")
    def process_action(*args)
      send_action(*args)
    end
  end
end

module ActionController
  class ActionArgsController < Base # new_base
  private
    def process_action(action_name)
      super(action_name, *action_arguments_for(action_name))
    end

    def action_arguments_for(action_name)
      # implementation returning array which containes values from params hash
      # uses default values and raises error for bad requests
    end
  end
end