I want to combine Shane Hathaway's BTreeFolder product with ZPatterns to create a "BTree folder w/ Customizer support". This has obvious advantages over the current "Folder w/ Customizer support" when you have a large number of DataSkin subobjects, both in terms of performance, and in terms of user-interface. The easiest way for me to do this would be to ask Phillip to make such a thing a standard part of ZPatterns :-) This is a little more difficult to do as a separate product, without lots of cut-and-paste reuse. (At least, it seems that way at first site.) the problem is that the inheritance heirarchy for CustomizerFolder (meta_type is "folder w/ customizer support") is like this: PlugInBase Folder ^ ^ |_______________| | PlugInContainer ^ | CustomizerFolder Without seriously delving into the code, I think I'd have to reimplement PlugInContainer. Instead, why not make PlugInContainer a mix-in class, and have concrete classes for PlugInFolder and PlugInBTreeFolder ? Then, it is easy to have a CustomizerFolder and a CustomizerBTreeFolder. Then again, I wouldn't mind if things stay as they are, except that PlugInContainer is made to derive from BTreeFolder rather than Folder. Of course, that creates a dependency that you need the BTreeFolder product in order to use ZPatterns. -- Steve Alexander Software Engineer Cat-Box limited http://www.cat-box.net