I've never seen this before:
class Admin::PaymentsController < Admin::BaseController belongs_to :order end
What does this mean, exactly?!
(This code is from Spree)
Thanks!
It's from the plugin resource_controller and makes Payments a nested resource under Order.
See the docs for resource controller http://github.com/jamesgolick/resource_controller
alternatively, the readme for resource_controller is in the vendored copy in spree in vendor/plugins