Rails/Devise - Determining when user session will expire

Question

When using the timeoutable module for Devise, how can one determine how long it will be before the current user's session expires? The goal is to include this value in all responses so client side script can make use of it. I gather that Devise internally uses Warden for authentication, but I haven't found anything that explains how to pull the session expiration time out of the depths of Warden.

Answer 1

Here is how you do it:

class User < ActiveRecord::Base
  devise :authenticatable, :timeoutable, :validatable, :timeout_in => 20.minutes
end