Helpers in Rails engine

Question

I am working on a rails engine and I have a problem with the helpers.

Apparently this is a known "problem" but there's not a lot of solutions out there. The problem is that I have an AuthenticationHelper which I want to access globally - but it's not working.

I've read that you could add a few lines to your init.rb but it does not seem to have any effect.

Any idea what the best way to make an application available in an engine?

EDIT: Fixed it- Just put the code (from the link) in the engine.rb instead.

Can you provide an example of the code you put in engine.rb? — westonplatter, Aug 31 '12 at 18:50

score 10 · Answer 1 · answered Sep 04 '12 at 05:04

10

Put this code in engine.rb:

config.to_prepare do
  ApplicationController.helper(MyEngineHelper)
end

answered Sep 04 '12 at 05:04

Brad Werth

17,411
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inside class Engine < Rails::Engine ? – linjunhalida Nov 29 '12 at 07:02
1

For posterity: this is no longer necessary - rails now automatically loads all helpers – danielpcox Jan 25 '13 at 19:00
3

Running rails 3.2.12... Had to add this to access methods within ApplicationHelper – Patm Mar 06 '13 at 20:26
`/vendor/extensions/categories/lib/refinery/categories/engine.rb:11:in 'block in ': undefined method 'helper' for Refinery::ApplicationController:Module (NoMethodError)` – Chloe Apr 08 '14 at 18:52
try `::ApplicationController.helper(MyEngineHelper)` or `ActionController::Base.helper(MyEngineHelper)` , maybe? – Brad Werth Apr 08 '14 at 19:14

Alex Fedoseev · Answer 2 · 2014-02-15T11:52:06.663

3

To access main app helpers (ApplicationHelper) from engine's views I tried include this:

app/helpers/your_engine/application_helper.rb

module YourEngine
  module ApplicationHelper
    include ActionView::Helpers::ApplicationHelper
  end
end

It works, but once, when I restarted dev server, it throws me uninitialized constant ActionView::Helpers::ApplicationHelper, but I can't reproduce this exception.

EDIT

Removed this include and made this one:

lib/my_engine/engine.rb (it's inside engine)

module MyEngine
  class Engine < ::Rails::Engine
    isolate_namespace MyEngine
    config.to_prepare do
      ApplicationController.helper(ActionView::Helpers::ApplicationHelper)
    end
  end
end

edited Feb 15 '14 at 11:52

answered Feb 15 '14 at 00:55

Alex Fedoseev

1,135
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1

I had to change the .helper line in Rails 4.2 to this: ApplicationController.helper(::ApplicationHelper) ... That might even have worked with your first solution. – Allen Jul 01 '15 at 16:15
I follow this solution and application_helper works fine, but when I run `rails console`, I got "uninitialized constant ActionView::Helpers::ApplicationHelper (NameError)". Does someone knows the reason? – Bater Chen Dec 01 '21 at 06:48

score 0 · Answer 3 · answered Jul 06 '22 at 17:57

Adding this just in case:

I had the same problem using the Administrate gem with Rails 7. I wanted to access my main app helper modules.

Simply adding helper all_helpers_from_path 'app/helpers' in Admin::ApplicationController solved this. You can find the official documentation here.

My file now looks like this:

module Admin
  class ApplicationController < Administrate::ApplicationController
    before_action :authenticate_admin_user!
    helper all_helpers_from_path "app/helpers"
  end
end

I found the answer here.

Helpers in Rails engine

3 Answers3

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