[Zope3-dev] Some Z3 thoughts

[Jim Washington]

Jim Fulton wrote:

> Lennart Regebro wrote:
> > Jim Fulton wrote:
> ...
>
> >>> Inconstistencies:
> >>>
> >>>   - ContainerTypesCONSTRAINT / ItemTypePRECONDITION ???
> >>>     They do the same thing!
> >>
> >>
> >>
> >> No, they don't.  They are both about constaining the containment
> >> relationship, from different ends.
> >
> >
> > Yeah, but one is called contraint, and the other precondition. ;)
> > No big deal, it just stood out to me as an inconsistency in something
> > othwerwise carefully consistent.
>
> Ah, I see what you mean. Note that I'm not very happy with this yet. I 
> think
> we're going to find a better way to do this.
>
> Also note that there is already a simpler way to do this.  See the 
> containment
> section in:
>
>    http://dev.zope.org/Zope3/programmers_tutorial.pdf
>
I was looking at that, and mutual relationships (A can only be in B, and 
B can only contain A) are still not trivial to do, since you need one 
defined before you can use the other, and vice-versa.  The work-around 
seemed like unnecessarily multiplying categories.  Could containment 
policy go in ZCML instead?  The activity seems to be more about 
configuration than behavior.

-Jim Washington