Would You like a Dynamic "extends"?

So, where would this be a problem? Well, lets say you have a set of base classes shared between n-projects in a framework. Now lets assume you have a combination of objects (some at the framework level, some at the project level) that need to be able to extend those base classes. And finally imagine that you'd like the ability to overload the base classes for some projects but not others. So in project A UserObject extends BaseObject, but in project B, UserObject extends ProjectBaseObject which extends BaseObject. In addition, the UserObject may be in project B, but it may also be an object stored in the framework directory that is shared between different projects and needs to extend a different object depending on which project it is being called from.

I would like to be able to describe the "extends" logic in LightWire and to dynamically control extends in the same way I dynamically control injection of properties and dependencies.

Right now, the only solution I can think of is to ask LightWire to copy the beans into a temporary directory, Regex the appropriate dynamically agreed extends attribute into the and then to call that bean. In fact, to keep support for package security, you'd probably have to do something like gen them into the same directory as #BeanName#_temp.cfc or something otherwise all beans would be able to call package methods (as they'd have all been genned into the same directory). In fact, thinking about it, the ability to programmatically overload the directory you genned into might be cool - it would mean that you could take a UserObject which is custom to a project and a UserDAO that is shared between two, gen them both at runtime into the same directory and allow UserDAO.save() to have package (protected) security and still be callable from UserObject - cool :->

I know there are other ways of solving the problem of being able to overload shared base classes on a project by project basis, but for my proposed outcome this is the "least inelegant" solution I've come across to date. Obviously there would have to be both an application wide and bean specific control to switch this on so it's only used on applications and beans that need it.

This is pretty unexplored territory in CF (to the best of my knowledge). Apart from general grumbling when people first find out that extends can't be dynamic I haven't really heard anything about people playing with this (and I can get why - it's probably quite an edge case and you could argue against the whole approach).

So, anyone any opinions on this pro or con? Would anyone else be interested if such a feature made its way into LightWire? For anyone who likes the idea, any preferences on how it would work or the syntax it might use?

Any input gratefully received.