If you want every single page in the whole app to use the same layout, you can make one called “application.rhtml” and then you can remove all other layouts and every controller will use that layout by default.
Or you can specify a layout at the controller level
class MyController < ApplicationController
layout “public”
end
Or per action
def list render :layout=>“public”
end
I use application.rhtml as my main layout and then override it in controllers when I want to change it.