[Zope3-dev] IsarSprint topics - Zope 3 application components

[Helmut Merz]

Am Mittwoch, 8. September 2004 12:17 schrieb Martijn 
Faassen:
> Helmut Merz wrote:
> > - Reference Engine (this is my personal favorite here)
>
> I'm interested in this topic, but won't be at the
> IsarSprint. 

So I hope you will give us some remote support :-)

> Could you tell me more about what you have in
> mind for this?

I'd like to implement something like this:

class Task(...):

    subtasks=[]
    parenttasks=[]

    def assignSubtask(self, task):
         self.subtasks.append(task)
         task.parenttasks.append(self) # back reference


Basic question: Will this work when the objects involved are 
persistent?

When all tasks are in the same container we could work with 
the name field for referencing; or we could use the 
uniqueid utility.

But one should also care for the cases when a referenced 
object will be deleted - so we need some referential 
constraints that are checked automatically...

Also often the references might carry additional information 
(metadata / annotations), so they should be real objects.

And there might be some general ReferenceField schema 
class...

That's the reason why the Archetypes developers have 
invested considerable effort in developing a reference 
implementation - and changed it two times.

I won't suggest any Zope 3 implementation for this 
references stuff at the moment, but it would be fine if we 
could start the discussion.

> > - SOAP
>
> Don't forget REST. :)
> http://rest.blueoxen.net/cgi-bin/wiki.pl

Yeah - the SOAP topic wasn't my idea anyway ;-)

Helmut