module Devise::Models::Trackable

def self.required_fields(klass)
  [:current_sign_in_at, :current_sign_in_ip, :last_sign_in_at, :last_sign_in_ip, :sign_in_count]
end

def update_tracked_fields!(request)
  old_current, new_current = self.current_sign_in_at, Time.now.utc
  self.last_sign_in_at     = old_current || new_current
  self.current_sign_in_at  = new_current
  old_current, new_current = self.current_sign_in_ip, request.remote_ip
  self.last_sign_in_ip     = old_current || new_current
  self.current_sign_in_ip  = new_current
  self.sign_in_count ||= 0
  self.sign_in_count += 1
  save(:validate => false) or raise "Devise trackable could not save #{inspect}." \
    "Please make sure a model using trackable can be saved at sign in."
end