Polymorphic user with Devise

application_controller.rb

class ApplicationController < ActionController::Base
  protect_from_forgery
  include Concerns::DeviseRouting
end

authenticable_factory.rb

class AuthenticableFactory
  def self.set_authenticable_for(user)
    user.authenticable = build_authenticable_for user
    user.authenticable.save
  end

  def self.build_authenticable_for(user)
    user.authenticable_type.constantize.new
  end
end

devise_routing.rb

module Concerns
  module DeviseRouting
    extend ActiveSupport::Concern

    included do
      helper_method :after_sign_in_path_for
    end

    def after_sign_in_path_for(user)
      user.home_path
    end
  end
end

fan.rb

class Fan < ActiveRecord::Base
  has_one :user, as: :authenticable

  def home_path
    "/campaigns"
  end
end

promotor.rb

class Promotor < ActiveRecord::Base
  attr_accessible :kind, :name, :website
  has_one :user, as: :authenticable

  def home_path
    "/dashboard"
  end
end

schema.rb

ActiveRecord::Schema.define(:version => 20130613163955) do

  create_table "fans", :force => true do |t|
    t.datetime "created_at", :null => false
    t.datetime "updated_at", :null => false
  end

  create_table "promotors", :force => true do |t|
    t.string   "name"
    t.string   "kind"
    t.string   "website"
    t.datetime "created_at", :null => false
    t.datetime "updated_at", :null => false
  end

  create_table "users", :force => true do |t|
    t.string   "email",                  :default => "",    :null => false
    t.string   "encrypted_password",     :default => "",    :null => false
    t.string   "reset_password_token"
    t.datetime "reset_password_sent_at"
    t.datetime "remember_created_at"
    t.integer  "sign_in_count",          :default => 0
    t.datetime "current_sign_in_at"
    t.datetime "last_sign_in_at"
    t.string   "current_sign_in_ip"
    t.string   "last_sign_in_ip"
    t.integer  "authenticable_id"
    t.string   "authenticable_type",     :default => "Fan"
    t.datetime "created_at",                                :null => false
    t.datetime "updated_at",                                :null => false
  end

  add_index "users", ["email"], :name => "index_users_on_email", :unique => true
  add_index "users", ["reset_password_token"], :name => "index_users_on_reset_password_token", :unique => true

end

user.rb

class User < ActiveRecord::Base
  include Concerns::DeviseStrategies

  attr_accessible(
    :authenticable_type,
    :email,
    :password,
    :password_confirmation,
    :remember_me
  )

  belongs_to :authenticable, polymorphic: true
  
  delegate :home_path, to: :authenticable
  
  def create
    super
    AuthenticableFactory.set_authenticable_for self
  end
end