gistfile1.rb

class Cart::WizardWidget < Cart::BaseWidget

  has_widgets do
    setup(options)

    self << widget("cart/list",     :cart_list,     :display, purchase_order: @purchase_order)
    self << widget("cart/resume",   :cart_resume)
    self << widget("shipping/form", :shipping_form, :display, purchase_order: @purchase_order)
    self << widget("payment/form",  :payment_form)
    self << widget("authentication")
  end

  responds_to_event :selectShipping,        with: :select_shipping
  responds_to_event :shippingAddressSaved,  with: :select_payment
  responds_to_event :signIn,                with: :select_sign_in

  after_initialize :setup!

  def setup!(*)
    setup(options)
  end

  def setup(options)
    @purchase_order ||= options.fetch(:purchase_order, nil)
  end