Gradual engagement, persistent guest user with Devise

Question

I'm trying to set up gradual engagement in my utility app which people can use without registering e.g. notepad.cc and jsfiddle.net and I plan to create a guest user (with Devise) for the user when he 'writes' to the app.

I found this guide on the Devise wiki https://github.com/plataformatec/devise/wiki/How-To:-Create-a-guest-user which shows how to create a guest user for the duration of the browser session. What I want is for the user to continue using the same guest account in subsequent visits, until he signs up, maybe when I introduce subscription plans for more features.

How can I modify what's in the guide to make this possible?

Code in the guide linked above:

# file: app/controllers/application_controller.rb

class ApplicationController < ActionController::Base

  protect_from_forgery

  # if user is logged in, return current_user, else return guest_user
  def current_or_guest_user
    if current_user
      if session[:guest_user_id]
        logging_in
        guest_user.destroy
        session[:guest_user_id] = nil
      end
      current_user
    else
      guest_user
    end
  end

  # find guest_user object associated with the current session,
  # creating one as needed
  def guest_user
    User.find(session[:guest_user_id].nil? ? session[:guest_user_id] = create_guest_user.id : session[:guest_user_id])
  end

  # called (once) when the user logs in, insert any code your application needs
  # to hand off from guest_user to current_user.
  def logging_in
  end

  private
  def create_guest_user
    u = User.create(:name => "guest", :email => "guest_#{Time.now.to_i}#{rand(99)}@email_address.com")
    u.save(false)
    u
  end

end

And using it in the controller:

@thing.user = current_or_guest_user
@thing.save

Answer 1

After some yak-shaving I've managed to get it to work. Here's the working code:

class ApplicationController < ActionController::Base

  protect_from_forgery

  # if user is logged in, return current_user, else return guest_user
  def current_or_guest_user
    if current_user
      if cookies[:uuid]
        logging_in # Look at this method to see how handing over works
        guest_user.destroy # Stuff have been handed over. Guest isn't needed anymore.
        cookies.delete :uuid # The cookie is also irrelevant now
      end
      current_user
    else
      guest_user
    end
  end

  # find guest_user object associated with the current session,
  # creating one as needed
  def guest_user
      User.find_by_lazy_id(cookies[:uuid].nil? ? create_guest_user.lazy_id : cookies[:uuid])
  end

  # called (once) when the user logs in, insert any code your application needs
  # to hand off from guest_user to current_user.
  def logging_in
      # What should be done here is take all that belongs to user with lazy_id matching current_user's uuid cookie... then associate them with current_user
  end

  private

    def create_guest_user
        uuid = rand(36**64).to_s(36)
        temp_email = "guest_#{uuid}@email_address.com"
        u = User.create(:email => temp_email, :lazy_id => uuid)
        u.save(:validate => false)
        cookies[:uuid] = { :value => uuid, :path => '/', :expires => 5.years.from_now }
        u
      end

end

I will accept another answer if you can show me a better way to do this.

Answer 2

The above solution works great.

Don't forget to setuphelper_method :current_or_guest_user to make the method accessible in views. Took me some time to figure out.