object-architecture

Quick Object Architecture question

Scenario: I am building our order processing system. I have an Order object that will contain a Generics list of Invoice and PurchaseOrder objects. I'm pretty sure that I would include the Customer object within the Order object, but then I wonder how I would access that from within the Invoice/PurchaseOrder objects. It doesn't make sen...

Overridable Subroutine Without Default Behavior?

In a base class object, I have an overridable subroutine that I would like all derived objects to have the ability to include. However, they don't have to, and if it's not necessary for them to use it, I don't want them to be forced to declare it. To enforce this, I've left the default behavior empty. For example, here's my whole sub: P...