[Zope-dev] wrapping unexistent objects

[Casey Duncan]

Its easy to create an infinite loop. To avoid these, do attribute lookups=
 from=20
the instance __dict__ rather than directly from self:

IOW, don't do:

foo =3D self.foo

or getattr(self, 'foo')

(This can trigger another __getattr__ call)

Instead do:

foo =3D self.__dict__['foo']

(This won't cause another getattr call)

As for examples, there is a complex one in the CMF Skinnable module and a=
=20
simpler one in the Document module of my DocumentLibrary product.

-Casey

On Tuesday 03 December 2002 10:58 am, Maurizio Boriani wrote:
> >>>>> "Casey" =3D=3D Casey Duncan <casey@zope.com> writes:
>=20
>     Casey> If you want an object to be able to handle calls to
>     Casey> undefined methods, you'll probably need to use a
>     Casey> __getattr__ hook. They can be a little tricky to get right
>     Casey> (you want to filter out names that start with "_" or "aq"
>     Casey> or else you'll be in trouble), and they don't have access
>     Casey> to acquisition, but they will allow you to intercept calls
>     Casey> to arbitrary names on an object.
>=20
> have you some examples or docs about this? I'm tring using it but my pr=
oduct
> felt in an unfinisched loop. Any suggestion
>=20
>     Casey> -Casey
>=20
> TIA,
> baux
>=20