Zope 2.2.1, ZPatterns 0-4-1snap1 I can't add a Dataskin-derived ZClass beneath a Customizer Folder any more. I think the order of something in the initialization of ZClasses has changed in Zope. It appears that the DataSkin's datamanager isn't being found before __set_attr__ is called for the first time. __set_attr__ is being called with name="id" val="id_of_object" Interestingly, __init__ in DataSkins.py is also being called with the value id. This is because in ZClass.py:createInObjectManager, the id is given to __init__ in the first statement, and set as an attribute in the second. def createInObjectManager(self, id, REQUEST, RESPONSE=None): """ Create Z instance. If called with a RESPONSE, the RESPONSE will be redirected to the management screen of the new instance's parent Folder. Otherwise, the instance will be returned. """ i=mapply(self._zclass_, (), REQUEST) i._setId(id) I've fixed this by adding a test to the start of __set_attr__ of DataSkins.py: def __set_attr__(self,name,val,_v_dm_=_v_dm_): + if name=='id' and val==self.__dict__['id']: + return dm = self.__dict__[_v_dm_] Here's the traceback before I applied the patch: Error Type: KeyError Error Value: _v_dm_ Traceback (innermost last): File lib/python/ZPublisher/Publish.py, line 222, in publish_module File lib/python/ZPublisher/Publish.py, line 187, in publish File lib/python/Zope/__init__.py, line 221, in zpublisher_exception_hook (Object: RoleManager) File lib/python/ZPublisher/Publish.py, line 171, in publish File lib/python/ZPublisher/mapply.py, line 160, in mapply (Object: Drug_add) File lib/python/ZPublisher/Publish.py, line 112, in call_object (Object: Drug_add) File lib/python/OFS/DTMLMethod.py, line 172, in __call__ (Object: Drug_add) File lib/python/DocumentTemplate/DT_String.py, line 528, in __call__ (Object: Drug_add) File lib/python/DocumentTemplate/DT_With.py, line 133, in render (Object: Drug.createInObjectManager(REQUEST['id'], REQUEST)) File lib/python/DocumentTemplate/DT_Util.py, line 337, in eval (Object: Drug.createInObjectManager(REQUEST['id'], REQUEST)) (Info: REQUEST) File <string>, line 0, in ? File lib/python/ZClasses/ZClass.py, line 452, in createInObjectManager (Object: Drug) File lib/python/OFS/CopySupport.py, line 442, in _setId (Object: asdasd) File lib/python/Products/ZPatterns/DataSkins.py, line 208, in __set_attr__ (Object: asdasd) KeyError: (see above) -- Steve Alexander Software Engineer Cat-Box limited http://www.cat-box.net