module Spina
  module PagesControllerOverride
    extend ActiveSupport::Concern
    
    prepended do
      before_action :do_something
    end

    # You can override methods and make them do something else...
    def homepage
      super
    end
    
    # ...or you can add new code
    def do_something
      # do something interesting
    end
    
  end
end

Spina::PagesController.prepend(Spina::PagesControllerOverride)