[ZODB-Dev] Can I abort part of a transaction setting self._p_changed=0 ?

[Shane Hathaway]

Steve Spicklemire wrote:
> One of the problems with ZCVSFolder is containerish objects (e.g.,
> Folder, Specialist, etc). In Zope, these are all basically subclasses of
> ObjectManager. The problem is that if you want to commit a subclass of
> ObjectManager you get not only it's meta_data, but also its contents. My
> idea is to set up a system that essentially does:
> 
> def CommitMetaDataOfObjectManager(self, anObjectManager):
> 
>         holder = anObjectManager._objects
>         delete anObjectManager._objects
>         result = self.CommitObject(anObjectManager)
>         anObjectManager._objects = holder
>         return result
> 
> so that the 'committed' objectManager is stripped of it's objects,
> committed, and then it's objects are restored. (it would be great if
> ObjectManager could present an interface that did that!). The problem is
> that fiddling with _objects will set the _p_changed flag and introduce
> an unwanted side effect of updating ZODB. Can I force _p_changed=0?
> Would that make this a thinkable possibility?

The act of modifying a persistent object or setting _p_changed to 1
causes cPersistence to register the object with the transaction manager
to be written, so by the time you set _p_changed to 0 it's too late.

I don't have a good solution for you, so I didn't reply earlier, hoping
someone else might.

Shane