[Zope-dev] Two glaring omissions

Toby Dickenson tdickenson@geminidataloggers.com
Thu, 16 Nov 2000 13:05:06 +0000


On Tue, 14 Nov 2000 15:39:59 -0500, Shane Hathaway
<shane@digicool.com> wrote:

>> 2. The ability to rename properties after instances of the classes have
>>    been created (and have the data in those fields preserved)
>
>This is also more difficult than it sounds.  You'd have to either scan
>through the entire ZODB and modify class instances or associate
>properties with a magical, unchanging ID.  The latter solution is dead
>wrong, but the first is actually kind of interesting.  If there were a
>separate index for each object type in the ZODB, it would be possible. 
>In fact, when ZODB is running from a relational database, there is
>indeed a way to do that.  Hmmm...

Or if your ZClass has a python base class, then a __setstate__ method
could be added to do the same thing incrementally. Like all changes to
a Python base class, this requires restarting the server.

Toby Dickenson
tdickenson@geminidataloggers.com