Question

I’m trying to view my new action in my blogs controller, but I keep getting the following error message:

NameError in BlogsController#new
undefined local variable or method `authenticate_admin'

In my blogs controller, I want to restrict the new action to admins only (admins and users are two different models). I was able to get this to work in another model. If I’m not mistaken, helpers are open to all classes. I also tried to add the code from my admins helper to the blogs helper, but that didn’t work.

Why can’t my blogs controller use my authenticate_admin method?

Thanks for lookign 🙂

Here are relevant files:

blogs_controller.rb

class BlogsController < ApplicationController
before_filter :authenticate_admin, :only => [:new]

  def new
    @blog = Blog.new
    @title = "New Article"
  end
end

admins_helper.rb

def authenticate_admin
  deny_admin_access unless admin_signed_in?
end 

def deny_admin_access
  redirect_to admin_login_url, :notice => "Please sign in as admin to access this page."
end

def admin_signed_in?
  !current_admin.nil?
end

def current_admin
   @current_admin ||= Admin.find(session[:admin_id]) if session[:admin_id]
end

Answer 1

In this case Helpers are accessible in your Views not in Controllers.

Solution is to move your methods from admins_helper.rb to ApplicationController and set them as helper_methods. You will be able to access them in your Controllers and Views.

Example:

class ApplicationController < ActionController::Base

  # Helpers
  helper_method :authenticate_admin

  def authenticate_admin
    deny_admin_access unless admin_signed_in?
  end 

end

Read documentation about helper_method:

http://api.rubyonrails.org/classes/AbstractController/Helpers/ClassMethods.html#method-i-helper_method