[ZODB-Dev] question

[Christian Reis]

On Wed, Sep 10, 2003 at 02:12:10PM -0400, Shane Hathaway wrote:
> Christian Reis wrote:
> >On Wed, Sep 10, 2003 at 11:13:06AM -0400, Shane Hathaway wrote:
> >>I'm suggesting that when you open a dialog, you make a temporary copy 
> >>of the data.  That's not a hack--it's a standard object-oriented clone 
> >>operation.  Implement "cancel" by discarding the copy and "ok" by 
> >>putting the new data in the database.  It adds very little code and 
> >>might even simplify things.
> >
> >
> >The problem that results from this is that this object may be a
> >composite object, and have references to other objects that need to be
> >accessible in the clone, so creating the clone itself is not trivial.
> >
> >Would the clone be produced using simple __dict__ introspection? Or
> >something like __new__?
> 
> Use a trivial deep copy.  (Although copy.deepcopy() doesn't like 
> ExtensionClass, so if you're using ZODB 3.2 or below, you need to use 
> cPickle to make the deep copy.  I can show you how if you're need it.)

Please do, that's something I've often wondered about.

> Splitting up transactions would open major holes.  You'd need something 
> quite unlike ZODB to get it right.  Making temporary copies is much 
> simpler.

Okay, okay -- if only because you said so ;-)

Take care,
--
Christian Reis, Senior Engineer, Async Open Source, Brazil.
http://async.com.br/~kiko/ | [+55 16] 261 2331 | NMFL