[Zope-dev] Dataskin Zclass + Folder subclassing problem

[Jean Lagarde]

Thanks Steve,

No doubt that is probably what is happening. Sadly, I need ZClass1 to be
a dataskin. I could always copy over the few properties and methods
shared by ZClass1 and ZCLass2 to ZCLass2 and inherit only from DataSkin
and Folder; not the nicest, but that would work for now. My approach to
access the contained objects directly (and not attempt to list them)
seems to work for now as well.

If I find the time, I will investigate this further to see what is
happening exactly.

Cheers,

Jean

> -----Original Message-----
> From: Steve Spicklemire [mailto:steve@spvi.com] 
> Sent: Friday, November 30, 2001 03:13
> 
> Hi Jean,
> 
> 	You might get more feedback from the ZPatterns list on 
> something 
> like this. My "gut" reaction is that subclassing in python 2.1/1.5 
> traverses the classes to find methods in a way that makes the 
> *order* of 
> classes very important. IIUC Python 2.2 has a much more sophisticated 
> attribute searching scheme, so that this will be easier to 
> get right.. 
> but so far Zope and 2.2 don't mix so well. You are no doubt 
> getting the 
> wrong class/attributes when you call objectIds etc. Can you 
> try making 
> ZClass1 a simple class and ZClass2 subclassing from DataSkin, 
> Folder and 
> *then* ZClass1?
> 
> good luck!
> -steve
> 
> On Tuesday, November 27, 2001, at 12:36 PM, Jean Lagarde wrote:
> 
> > Hi all,
> >
> > A ZClass inheriting from both DataSkin and Folder seems to work as 
> > expected (so much has been discussed in other messages, at 
> least with 
> > ObjectManager). However, instead of inheriting directly 
> from DataSkin, 
> > I want to inherit from another Zclass which is itself based on 
> > DataSkin, i.e. (not showing Zobjects):
> >
> >          DataSkin          ZClass1    Folder
> >             |                 \         /
> >             |                  \       /
> >             v                   v     v
> >          ZClass1                ZClass2
> >
> > After its creation, the new Zclass ZClass2 seems to have some 
> > management
> > issues:
> >
> > - The views are initialized to those of ZClass1; no big 
> deal, for now, 
> > I just added a new view tab named Contents for manage_main
> >
> > - When I create an instance of ZClass2 (in a Folder w/Customizer 
> > Support), the instance does show its Contents tab, but it does not 
> > quite know it's folderish:
> >
> >   - It does not show in the left pane of the ZMI
> >
> >   - If I add an object from the contents tab interface of the 
> > instance, say a dtml method, it adds OK, but does not show in the 
> > contents tab (the contents view is always empty no matter 
> what I add)
> >
> >   - The objects I added are there; I can traverse to them and their 
> > management interfaces, and I have also checked the ZODB 
> directly using 
> > the wonderful pyTree.py.
> >
> > I'm afraid that I know just enough about Zope to be dangerous ;-) I 
> > basically just have the time to learn about the stuff that 
> I need to 
> > get the job done, and I'm sure that the current version of what I'm 
> > working on will need some refactoring later on. So I have two 
> > questions:
> >
> > 1) Anybody can think of a quick fix to get the folderish behavior 
> > working as it should?
> >
> > 2) In its current state (if there is no quick fix), ZClass2 seems 
> > usable enough for my needs; I just need to add a couple of 
> objects for 
> > each instance, and I can reach their management screens through 
> > explicit traversal. So I'm tempted to plug along and keep on 
> > experimenting with that setup for now. Any other more important 
> > consequences that I'm missing that should have me fix this more 
> > adequately before I proceed?
> >
> > Cheers,
> >
> > Jean
> >