addClassAdvisor(callback, depth=2)
Set up callback
to be passed the containing class upon creation
This function is designed to be called by an "advising" function executed in a class suite. The "advising" function supplies a callback that it wishes to have executed when the containing class is created. The callback will be given one argument: the newly created containing class. The return value of the callback will be used in place of the class, so the callback should return the input if it does not wish to replace the class.
The optional depth
argument to this function determines the number of
frames between this function and the targeted class suite. depth
defaults to 2, since this skips this function's frame and one calling
function frame. If you use this function from a function called directly
in the class suite, the default will be correct, otherwise you will need
to determine the correct depth yourself.
This function works by installing a special class factory function in
place of the __metaclass__
of the containing class. Therefore, only
callbacks after the last __metaclass__
assignment in the containing
class will be executed. Be sure that classes using "advising" functions
declare any __metaclass__
first, to ensure all callbacks are run.