[Zope-dev] Bugtracker for z3c.relationfield and reasons for objects loosing their parent pointers

[Patrick Gerken]

Hi,

I found out, somewhat surprised, that __parent__ pointers are just
disguised aq_parent pointers.
The changelog entries for zope 2.12 are a bit misleading in this regard.
Is there somewhere an explanation of how this works? I was quite by
some of the properties.

Best regards,

         Patrick


On Tue, Mar 27, 2012 at 00:09, Patrick Gerken <do3ccqrv at googlemail.com> wrote:
> Hi,
>
> I have a very curious problem with relationfields, and I don't know
> which bugtracker to use for z3c.relationfield.
> So, hopefully somebody here can give me some pointers.
>
> The relations are persistent objects and the from relation is stored
> directly on them on the from_object.
>
> For some reason, the existing relations have from objects without
> __parent__ or aq_parent pointers.
> When I update a relation, from_object is updated with an object with
> __parent__ and aq_parent pointers.
> After restart, the pointers are gone, the attribute value is None.
> When I want to delete the relation target object, Plone first starts a
> savepoint, tries to delete the object, catches any exceptions and does
> a rollback. It does so to test for certain exception. After the
> rollback, the objects lost their __parent__ and aq_parent pointers.
> There was something else that felt odd. the object in from_object
> always returned a string representation without a path on
> obj.__str__(), but a string representation with a path when doing
> obj.__repr__() and when the object had __parent__ pointers. I noticed
> that, because print statements and pdb tests displayed different
> things.
> The whole thing happens in Zope 2.13 with dexterity content types.
> I have no idea why this could happen. Anybody has any  pointers for me?
>
> Thanks and best regards,
>
>       Patrick