[Zope3-dev] Yet Another Relations (aka Reference) Engine...

[Jean-Marc Orliaguet]

Helmut Merz wrote:

>Anyway, what we are talking about are not "references".
>  
>

The approach is quite different: references start from the objects
themselves that they connect to other objects using one-way relations (a
pointer, an arrow). The application has to know how to interpret the
references. I don't think that you can build a robust relation engine
only with that.

Relations start from "the top": you first define an ontology (a set of
general predicates) that you use to relate the objects of your
application. This is a conceptual schema. Here is the cpsskins ontology:
http://svn.nuxeo.org/trac/pub/file/z3lab/cpsskins/branches/jmo-perspectives/ontology.py

The relation engine then manages all the necessary references, but the
application does not need to know about the references at all. The
interaction with the relation engine is done only via the ontology.

To compare with python: references are to relations what methods are to
classes. A set of unrelated methods doesn't make a model, similarly a
set of loose references doesn't make an ontology.

/JM