Where to put Ruby helper methods for Rails controllers?

Question

I have some Ruby methods certain (or all) controllers need. I tried putting them in /app/helpers/application_helper.rb. I've used that for methods to be used in views. But controllers don't see those methods. Is there another place I should put them or do I need to access those helper methods differently?

Using latest stable Rails.

Neogaea

Answer 1

You should define the method inside ApplicationController.

Harrelson

He will also have to add helper_method :my_helper_method in ApplicationController to make them available to the views. – Intercommunion

wont this lead to a fat controller over time? – Rigger

also @Intercommunion that violates MVC – Rigger

Answer 2

For Rails 4 onwards, concerns are the way to go. There was a decent article which can still be viewed via the Wayback Machine.

In essence, if you look in your controllers folder you should see a concerns sub-folder. Create a module in there along these lines

module EventsHelper
  def do_something
  end
end

Then, in the controller just include it

class BadgeController < ApplicationController
  include EventsHelper

  ...
end

Trolley

I find this the nicest solution when you don't need the helper methods included in all your controllers. This solution also applies to models. – Totality

Do you know if we need to use extend ActiveSupport::Concern with controller concerns? – Drogue

No need to do extend ActiveSupport::Concern inside controller/concerns directory. You just need to define modules above directory and can simply do include as mentioned above(for rails 4.2 and rails 5). – Overglaze

probably the best answer – Panicle

Can this method be accessed from View? – Samiel

Answer 3

you should define methods inside application controller, if you have few methods then you can do as follow

class ApplicationController < ActionController::Base    
  helper_method :first_method
  helper_method :second_method

  def first_method
    ... #your code
  end

  def second_method
    ... #your code
  end
end

You can also include helper files as follow

class YourController < ApplicationController
  include OneHelper
  include TwoHelper
end

Ain

is there a way to assign all the helper_methods on one line? – Wastepaper

@HarshaMV I think you can just go ahead like helper_method :first_method, :second_method. – Rheinland

Answer 4

You can call any helper methods from a controller using the view_context, e.g.

view_context.my_helper_method

Intercommunion

There's a more modern version of this answer for Rails 5+: https://mcmap.net/q/116632/-rails-how-to-use-a-helper-inside-a-controller – Underling

Answer 5

Ryan Bigg response is good.

Other possible solution is add helpers to your controller:

class YourController < ApplicationController
  include OneHelper
  include TwoHelper
 end

Best Regards!

Decapitate

Answer 6

Including helpers in controller will end-up exposing helper methods as actions!

# With new rails (>= 5) 

helpers.my_helper_method


# For console

helper.my_helper_method

Unscratched