routes.js.rb

  attr_accessor :page, :viewer, :menu
  
  def element
    @element ||= Element
  end

  def with selector
    sub_element = element.find(selector)
    yield sub_element if sub_element.any?
  end

  def setup
    with '.site-index' do |menu_element|
      self.menu = MenuView.new(menu_element)
    end

    with 'section.page' do |page_element|
      self.page = PageView.new(page_element)
    end

# ...