title: Devise helper methods do not exist
body: <p>I'm using devise for authenticating users in my app. The problem is that none of the devise helpers exist in my app. For example. In file <code>app/controllers/admin/dashboard.php</code> I have this snippet of code:</p>
  
  <pre><code>&lt;% if user_signed_in ? %&gt;
     do something
  &lt;% end %&gt;
  </code></pre>
  
  <p>I get </p>
  
  <pre><code>undefined method `user_signed_in?' 
  </code></pre>
  
  <p>Here is the output of the <code>rake routes</code> command </p>
  
  <pre><code>new_admin_session           GET    /admin/sign_in(.:format)         devise/sessions#new
  admin_session               POST   /admin/sign_in(.:format)         devise/sessions#create
  destroy_admin_session       DELETE /admin/sign_out(.:format)        devise/sessions#destroy
  admin_password              POST   /admin/password(.:format)        devise/passwords#create
  new_admin_password          GET    /admin/password/new(.:format)    devise/passwords#new
  edit_admin_password         GET    /admin/password/edit(.:format)   devise/passwords#edit
                              PUT    /admin/password(.:format)        devise/passwords#update
  cancel_admin_registration   GET    /admin/cancel(.:format)          devise/registrations#cancel
  admin_registration          POST   /admin(.:format)                 devise/registrations#create
  new_admin_registration      GET    /admin/sign_up(.:format)         devise/registrations#new
  edit_admin_registration     GET    /admin/edit(.:format)            devise/registrations#edit
                              PUT    /admin(.:format)                 devise/registrations#update
                              DELETE /admin(.:format)                 devise/registrations#destroy
  login                              /admin/login(.:format)           devise/sessions#new
  login                              /admin(.:format)                 devise/sessions#new
  admin_dashboard_index       GET    /admin/dashboard/index(.:format) admin/dashboard#index
  </code></pre>
  
  <p>Here is the content of routes.rb</p>
  
  <pre><code>devise_for :admin
  
    devise_scope :admin do
      match 'admin/login' =&gt; 'devise/sessions#new', :as =&gt; :login
      match 'admin' =&gt; 'devise/sessions#new', :as =&gt; :login
      get "admin/dashboard/index"
    end
  
    namespace :admin do
      resources :images
    end
  </code></pre>
  
  <p>And Admin model</p>
  
  <pre><code>class Admin &lt; ActiveRecord::Base
  
    devise :database_authenticatable, :registerable,
           :recoverable, :rememberable, :trackable, :validatable
  
    attr_accessible :email, :password, :password_confirmation, :remember_me 
  
  end
  </code></pre>
  
  <p>What is wrong here? I'm able to register or log-in, but I can't use helper methods.</p>