Conditionally render different layouts in Rails

Suppose you have two different layout files:

• application.html.erb: for logged in users
• guest.html.erb: for guest users

You can add the following to your base ApplicationController to render a different layout based on the user’s authentication status:

class ApplicationController < ActionController::Base
  layout :layout

  private

  def layout
    user_signed_in? ? 'application' : 'guest'
  end
end 

Assuming your controllers extend ApplicationController (as is the default convention), your views will use the application layout when the user is signed in and the guest layout when they aren’t signed in.