Did you check the work Seth and I did?:
http://www.jason-parks.com/artoftech/?p=225
What "things" could you not do in your __init__ method. Doesn't
_postCreateVirtual essentially replace the __init__ method?
We've used this technique successfully on a couple of classes so far.
Though we haven't put it through its paces too seriously. I'm about to
extend the factory created nt.hikCharacterNode class to wrap all the
non-documented MEL methods to the new HIK character node. After that, I
should have an even more familiar knowledge of the subclassing process.
-jason
On Saturday, October 13, 2012 1:23:09 AM UTC-7, Morgan wrote:
>
> Hey all, I've been using sort of a hacky method for extending pymel, and
> I've just now been trying to get my head around subclassing with virtual
> classes to upgrade my code.
>
> The way I've been doing it up to now is not inheriting directly from pymel
> node classes, but rather creating a custom class and storing the pyNode
> object in a member variable, and then overriding the __getattr__ method to
> have access to the pyNode methods as well as my own custom methods. It
> looks something like this:
>
>
> class MyTransform(object):
>
> def __init__(self):
>
> self.__pyNode = pm.createNode('transform')
>
> #any sort of custom stuff, adding attributes and assigning member
> variables.
>
> def someCustomMethod(self):
>
> #do custom stuff
>
> def __getattr__(self, attr):
>
> if attr in self.__dict__:
>
> return self.__dict__[attr]
>
> else:
>
> return getattr(self.__pyNode, attr)
>
>
> It's then easy to inherit from this, for example MyJoint could be
> inherited from MyTransform and have access to someCustomMethod, as well as
> the methods that are unique to the pymel Joint class. Of course the
> downside is that it's not a real subclass, just kind of a wrapper, and it
> has some limitations.
>
> Anyway, I got the virtual class stuff working from the examples, but as I
> started converting my first couple classes I've run into some snags that I
> wasn't sure about the best way to get around. The way I'm approaching this
> conversion is I'm replacing __init__ with _preCreateVirtual, createVirtual,
> and _postCreateVirtual, more or less. But some of the things I was doing in
> my __init__ methods, such as setting member variables and calling methods
> from this class and parent classes, doesn't seem to be possible. And
> neither is adding an __init__ method, because special methods aren't
> allowed in virtual classes. I'm kind of pushing the limit of my current
> python knowledge with this stuff, so I'm not really sure where to go next.
> My only thought was to create a wrapper function for each class to actually
> call it and then assign or edit any member variables or do anything else I
> can't figure out how to do during creation. But is there some better way of
> dealing with this that I'm not understanding?
>
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