tap/app/controllers/application_controller.rb

class ApplicationController < ActionController::Base
  # Prevent CSRF attacks by raising an exception.
  # For APIs, you may want to use :null_session instead.
  protect_from_forgery with: :exception
  include SessionsHelper
  include ProductsHelper
  include OrdersHelper

  private

    # Confirms a logged-in user.
    def logged_in_user
      unless logged_in?
        store_location
        #flash[:danger] = "Please log in."
        redirect_to login_url
      end
    end
end