Ivars in GUI classes

[Chris Farber]

Hello everyone,

I'm beginning to add bindings to the classes listed here:
http://developer.apple.com/documentation/Cocoa/Reference/ 
CocoaBindingsRef/index.html#//apple_ref/doc/uid/10000189i

In order to add a binding, a few pieces of information have to be  
kept track of, such as the value transformer, bound object and key  
path, and other options. One way to do this would be to add instance  
variables to the classes, but I am not sure if there would be any  
negative consequences of this. If you look at the headers on Mac OS  
X, it appears this is not the route Apple took. Alternatively I could  
put these in global map tables or dictionaries and use locks to make  
it thread-safe, but this would be a lot more work (and potentially  
slower?).

I'd appreciate any advice on which route to take.

Thanks,
Chris Farber