Hotwire Native for Rails Developers

Keep Users Signed In Between App Launches

Have you noticed that every time you launch the app you have to sign in again? Mobile app users expect to remain signed in even after they close or background an app. Let’s fix that.

Check out the Authentication concern^[24] in the Rails codebase. This module is included in ApplicationController to authenticate users. The #sign_in method persists the user’s ID to an encrypted cookie when they sign in.

ch02_13/rails/app/controllers/concerns/authentication.rb

module Authentication
  extend ActiveSupport::Concern

  included do
    helper_method :current_user, :user_signed_in?
  end

  def sign_in(user)
    Current.user = user
    cookies.encrypted[:user_id] = user.id
  end

  ...