Re: Changing and migrating persistence structure
Martin Aspeli <[email protected]>
| Newsgroups | gmane.comp.web.zope.devel |
|---|---|
| Message-ID | <[email protected]> |
On 8 August 2010 20:29, Hanno Schlichting <[email protected]> wrote: > There should be some way of doing this with custom __getstate__ and > __setstate__ methods. > > It's just tricky to get right and a bit fragile. It's much easier to > write the migration code if both the old and new class are separate > and functioning at the same time. The main problem is that the advertised API says you should do: from plone.registry import Record from plone.registry import field registry['foo.bar'] = Record(field.TextLine(), u"my value") Here, field.TextLine derives from PersistentField which derives from Persistent, and Record derives from Persistent also. If I wanted to get rid of the Persistent base, I'd have to make a new "tree" of field types (the standard zope.schema ones still need some subclassing), and a new Record class with a less obvious name. Martin _______________________________________________ Zope-Dev maillist - [email protected] https://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - https://mail.zope.org/mailman/listinfo/zope-announce https://mail.zope.org/mailman/listinfo/zope )