How to determine which controller has been called from ApplicationController?

Question

I would like to put one method inside my ApplicationController and launch it only in case when some controllers are called. Similarly to devise parameters sanitizer:

before_action :configure_permitted_parameters, if: :devise_controller?

I've tried:

before_action :recent_discussions, if: :first_controller? || :second_controller? || :third_controller?

However first_controller? etc are undefined methods.

Is there a way to call something in ApplicationController only under specific controllers?

Answer 1

Presuming you meant || instead of && in your question's pseudo code ( && makes no sense), this would work:

FANCY_CONTROLLERS = %w[FirstController SecondController ThirdController]
before_action :recent_discussions,
  if: proc { FANCY_CONTROLLERS.include? "#{controller_name.camelize}Controller" }

Answer 2

Put this in your application controller

class ApplicationController < ActionController::Base
  # more code

  def special_controller?
    controller = params[:controller]
    special_controllers = %w(first second third)
    special_controllers.include? controller
  end
end

And put this in your special controllers

class FirstController < ApplicationController
  before_action :recent_discussions, if: :special_controller?

  # more code
end

Answer 3

You can use request.referrer to get the path of the previous action.

To get the controller responsible for that action, use: Rails.application.routes.recognize_path(request.referrer)[:controller]

Answer 4

You could define private method def my_controller?; end def my_controller?; end in ApplicationController , and use filter before_action :recent_discussions, if: :my_controller?

Then, in controllers you want this code actually run, redefine def my_controller?; true; end def my_controller?; true; end