[Pyobjc-dev] Bundle loading hooks?

[Ronald O. <ous...@ci...>]

Hi,

I'm one of the authors of PyObjC, which is a Python extension module 
that allows you to write Cocoa classes in Objective-C. This works 
pretty well for normal code, but we ran into a problem w.r.t. dynamicly 
loaded bundles (plugins) and the NSBundle methods 'classNamed:' and 
'bundleForClass:'.

When you define a subclass of an Objective-C class in Python, the 
PyObjC module automaticly creates a Objective-C class for you and 
registers that with the runtime. That is, it creates the right C 
datastructures and tells the runtime about these using objc_addClass 
and the like. As mentioned before, this works just fine, these classes 
can be used in NIB files and the classes are found using 
NSClassFromString.

However, if you start querying with the NSBundle +bundleForClass:, all 
classes defined in Python seem to be defined in the main bundle even if 
they are actually defined in another (plug-in) bundle. Simularly, 
NSBundle -classNamed: will only find the class if you use the 
mainBundle. This is a problem for us, because this means Interface 
Builder cannot find the classes in a palette that has been defined in 
Python.

Does anyone know a documented way to get the administration right? I 
got the IB palette working with a dirty hack: when the python plugin it 
loaded it looks for the NSBundle that is associated with its bundle and 
changes the 'isa' pointer of that NSBundle instance to a subclass of 
NSBundle that overrides classNamed. That doesn't look like the proper 
solution to me :-)

Ronald