[Zope] Acquiring parent objects through BTrees

[Joseph Barillari]

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Hello,

I would like to know if it is possible for an object stored in a BTree
to use acquisition to see its parent object (either the BTree itself
or the object that holds the BTree).=20

Here's an example of what I've tried:

Python 2.1.1 (#1, Jul 29 2001, 19:04:01)=20
[GCC 2.96 20000731 (Red Hat Linux 7.1 2.96-85)] on linux2
Type "copyright", "credits" or "license" for more information.
>>> from Acquisition import Implicit
>>> from BTree import BTree
>>>=20
>>> class A(Implicit):
=2E..     pass
=2E..=20
>>> class B(Implicit):
=2E..     pass
=2E..=20
>>> class D(Implicit, BTree):
=2E..     pass
=2E..=20
>>> a =3D A()
>>>=20
>>> a.d =3D D()
>>> a.d     =20
<D instance at 8118330>
>>> a.d.aq_parent
<A instance at 8114c28>
>>> a.d[1] =3D B()
>>> a.d[1]     =20
<B instance at 8114c18>
>>> a.d[1].aq_parent
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
AttributeError: aq_parent

The Acquisition machinery has no problem with the regular
objects. Class D, which wraps a BTree and implicit acquisition, lets
the BTree see its parents, but an acquisition-enabled object placed in
an acquisition-enabled BTree still can't see its parent.

Any suggestions? Or is this a bad idea? Should I implement another
mechanism? The number of objects stored in the BTrees in the final
product is unlikely to be more than a few hundred, so another data
type might work.

Thanks,

Joe

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