How in Rails, in the parent class, to define a constant so that the value is different for "children"?

Question

ruby

Actually, the question is in the title.

I want to define a constant LOG_TAGin ApplicationController, but in such a way that in the controllers that inherit from it, its value would be calculated for each controller.

That is:

application_controller.rb:

class ApplicationController < ActionController::Base
  TAG = name
end

users_controller.rb:

class UsersController < ApplicationController
  def check_const
    puts TAG
  end
end

I want it to be UsersControllerdisplayed, but it is displayed ApplicationController.

Can I do it the way I want or not?
I know that you can define a method in the ApplicationController, but I want it to be a constant.

Thanks

Answer 1

you can use the inheritance hook and set the constant dynamically in each class that inherits from the parent

class ApplicationController
  def self.inherited(child_class)
    const_set("TAG", child_class.name)
  end
end

class UsersController < ApplicationController
  def check_const
    puts TAG
  end
end

UsersController.new.check_const # => UsersController

Answer 2

Alas, it is impossible, but you can give different values ​​​​for different call sources and this will already be a method, not a variable

Answer 3

class_attribute