[Zope] Re: [Zope-dev] Re: sessions in the presence of conflicts

[Chris McDonough]

Trimmed Zope-dev from this (cross-posts are bad)...

> Dennis,
> Lets just put the question out there:  Does:
>
> SESSION['someKey'] = someValue
>
> Force a commited transaction?
>
> As opposed to ...
> someDict = Session['SomeKey']
> someDict['aKey'] = 'aNewValue'

Neither "forces a committed transaction", but the former directly  
marks an object (the session object) as changed.  The latter does not  
mark any object as changed if someDict is actually a Python  
dictionary and not a first-class persistent object.  At the end of a  
transaction, only objects that are marked as changed are re-persisted  
to the database.

This is further explained in the "mutable subobjects" section of the  
sessions chapter of the Zope Book on plope.com.

- C