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.

score 78 · Accepted Answer · answered Nov 28 '12 at 19:54

78

You should define the method inside ApplicationController.

answered Nov 28 '12 at 19:54

Ryan Bigg

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He will also have to add `helper_method :my_helper_method` in `ApplicationController` to make them available to the views. – David Nov 28 '12 at 20:02
3

wont this lead to a fat controller over time? – Ben G Nov 20 '15 at 07:48
2

also @David that violates MVC – Ben G Nov 20 '15 at 07:58

score 74 · Answer 2 · edited Sep 04 '20 at 07:29

74

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

edited Sep 04 '20 at 07:29

Nil

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answered Oct 09 '14 at 13:03

John Cleary

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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. – Dennis Jan 21 '15 at 17:18
Nice. Thank you :) – tonyedwardspz Jun 17 '16 at 14:12
Do you know if we need to use `extend ActiveSupport::Concern` with controller concerns? – Marklar Feb 16 '17 at 00:14
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). – Ravindra M Jul 24 '17 at 05:06
probably the best answer – Anton Semenichenko Apr 04 '18 at 08:38
Can this method be accessed from View? – Jin Lim Apr 02 '20 at 22:21

score 30 · Answer 3 · answered Nov 28 '12 at 20:02

30

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

answered Nov 28 '12 at 20:02

Muhamamd Awais

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is there a way to assign all the helper_methods on one line? – Harsha M V Apr 17 '16 at 06:23
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@HarshaMV I think you can just go ahead like `helper_method :first_method, :second_method`. – Franklin Yu Sep 06 '16 at 00:56

score 21 · Answer 4 · answered Nov 28 '12 at 20:00

21

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

view_context.my_helper_method

answered Nov 28 '12 at 20:00

David

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There's a more modern version of this answer for Rails 5+: https://stackoverflow.com/a/11161692/12484 – Jon Schneider Mar 02 '23 at 21:55

score 8 · Answer 5 · answered Nov 28 '12 at 19:59

8

Ryan Bigg response is good.

Other possible solution is add helpers to your controller:

class YourController < ApplicationController
  include OneHelper
  include TwoHelper
 end

Best Regards!

answered Nov 28 '12 at 19:59

hyperrjas

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score 1 · Answer 6 · answered Jan 08 '20 at 05:08

1

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

answered Jan 08 '20 at 05:08

Aparichith

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Where to put Ruby helper methods for Rails controllers?

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