[Zope3-Users] Re: RFC 4122 UUIDs

[Derek Richardson]

Martin Aspeli wrote:
> 
> 
> Stephan Richter-2 wrote:
>> On Wednesday 04 April 2007 13:06, Derek Richardson wrote:
>>> I am hoping that Zope 3 assigns an RFC 4122 UUID to each content item.
>>> If not, I am hoping there is a third-party product to do this.
>> No there is neither. We have an intid utility that guarantees System-wide 
>> unique ids. This utility is used at several places most notably the
>> catalog.
>>
>>> I would like RFC 4122 UUIDs to provide standard Atom feeds of Zope
>>> content [1].
>>>
>>> It will be better if Zope itself assigns UUIDs, so that there is a
>>> single source and not a possibility of multiple packages assigning
>>> different UUIDs to the same content item.
>> You have to write your own utility to generate the UUID. I checked the RFC 
>> quickly and our IntIds are certainly not of the format requested by RFC
>> 4122.
>>
> 
> Presumably, the intid implementation would be a useful reference for such a
> utility, and this would a good canidate for a general, re-usable package.
> 
> Martin

Good. I would like to write it as a general, re-usable package.

Generating RFC 4122 UUIDs is easy - there's a routine for it in the 
python 2.5 standard libraries and a python 2.3+ version here:

http://zesty.ca/python/uuid.html

What seems more difficult is how to plug the routine in so that all 
content items receive one and only one UUID upon creation. Maybe listen 
for IObjectCreatedEvent and annotate then? Or is there a potential race 
condition that means events are not the way to go?

(Unsure of the depths of Zope 3's architecture)

Derek