The @app Object

application_controller.rb

class ApplicationController < ActionController::Base
  ...
  
  def intranet
    @intranet ||= Intranet.for_employee(current_user)
  end
  
  helper_method :intranet
end

intranet.rb

class Intranet
  ...
  def files(manager_source = FileManager.method(:new),
            browser_source = FileBrowser.method(:new))

    @files ||= if admin?
      manager_source.call
    else
      browser_source.call
    end
  end
end