[Zope3-Users] Non-owning references in Zope3

Gary Poster gary at zope.com
Wed May 24 16:33:30 EDT 2006


On May 24, 2006, at 4:27 PM, Alek Kowalczyk wrote:

> Tom Dossis wrote:
>> thealx at poczta.onet.pl wrote:
>>> Hi, I am relatively new to Zope3. I could not find anywhere an  
>>> example, what is the 'right way' to make non-owning reference to  
>>> another object in Zope? Every piece of zope3 docs is full of  
>>> examples of containers, this makes a good tree like structure.  
>>> But how to refer from one object to another in right way? Can/ 
>>> should I do that with Object field?
>> One offering is zc.extrinsicreference ... http://svn.zope.org/ 
>> zc.extrinsicreference/trunk/src/zc/extrinsicreference/ 
>> extrinsicreference.txt I'm not aware of any zope.schema /  
>> FieldProperty stuff to do this; it would be pretty useful though.
> Thanks! I have also found a references library in 'schooltool'  
> project. It seems to be similar to RDF and adapts any Annotatable  
> object. But I'm looking for something more straightforward - both  
> approaches (extrinct and schooltool) seem to be too complex and not  
> pythonic...

It sounds like you just want to make python references?  That works.

given A and B, two objects whose classes inherit from  
persistent.Persistent,

A.foo = B

and

B.bar = A

will work as you expect.  Haven't seen clear requirements for this  
from you, but maybe I missed them.

Gary


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