Using devise sign in, sign up views through your rails app

auth_helper.rb

# File : app/helpers/auth_helper.rb
# include this module in app/controllers/application_controller.rb
# include AuthHelper

# Module to define some functions to use devise views in any
# of your controllers to render sign_in or sign_up pages.
module AuthHelper
  # Included for devise_error_messages!
  include DeviseHelper

  def resource_name
    :user
  end

  def resource
    @resource ||= User.new
  end

  def devise_mapping
    @devise_mapping ||= Devise.mappings[:user]
  end
end