[Zope] Re: Zope 3 Newbie Persistent Question

[Tres Seaver]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Perry Smith wrote:
> I've read through 2/3rds of Web Component Development with Zope 3.  I am
> just now starting to create a simple system to hold contact information.
> 
> If I start simple with maybe five fields and make it persistent, what
> happens when I add fields later on?  Does the Zope database just
> magically understand that the old elements do not have all of the fields
> (yet).
> 

The simplest answer is "yes, but it isn't magic":  you would neeed to
provide a class-level default for the newly-added attributes.

zope.schema.fieldproperty.FieldProperty is a particularly good way to
set up those class-level defaults, as it uses the default value you
declare in the schema.


Tres.
- --
===================================================================
Tres Seaver          +1 202-558-7113          tseaver at palladion.com
Palladion Software   "Excellence by Design"    http://palladion.com
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.2.2 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFFKk7Z+gerLs4ltQ4RAtqDAJ0aFKIZC/0ZAhZRVjIzVJvqt4i2AACfaFDw
aGZKthGQWmzcWiLBybWdGsM=
=hFsS
-----END PGP SIGNATURE-----