Anyone have a technique for COS Class Polymorphism that should survive an upgrade?
I'm wondering if anyone has coded up a means to create an extension for a %Persistent class from a base class to a sub-class without making a ton of assumptions about the Global structure. I'm trying to create a new "extension" record that would have the same ID as the Base Class
Class BaseRecord Extends %Persistent
Class SubRecord Extends BaseRecord
where I would have an instance of a "BaseRecord" and I want to turn it into a "SubRecord" instance and have all of the existing references to the BaseRecord survive.
I know I could go after the globals themselves but this approach relies on an awful lot of low level knowledge that really shouldn't be poked around with and would only really work with a single storage definition.
Any suggestions? (besides 'don't do that')