well, for schema upgrades, also following patch seems to be necessary:
From c11064b8d8a7607d41071250f587f097f8c130a3 Mon Sep 17 00:00:00 2001 From: Johannes Raggam <raggam-nl@adm.at> Date: Tue, 15 Feb 2011 14:29:56 +0100 Subject: [PATCH 2/2] gracefully set newvalue for upgraded schemas, where oldvalue isn't available.
--- zope/formlib/form.py | 8 +++++++- 1 files changed, 7 insertions(+), 1 deletions(-) diff --git a/zope/formlib/form.py b/zope/formlib/form.py index 0d3ade3..ff10168 100755 --- a/zope/formlib/form.py +++ b/zope/formlib/form.py @@ -532,7 +532,13 @@ def applyData(context, form_fields, data, adapters=None): name = form_field.__name__ newvalue = data.get(name, form_field) # using form_field as marker - if (newvalue is not form_field) and (field.get(adapter) != newvalue): + try: + oldvalue = field.get(adapter) + except AttributeError: + # value not available after schema upgrade + # make sure that oldvalue != newwalue + oldvalue = not bool(newvalue) + if (newvalue is not form_field) and (oldvalue != newvalue): descriptions.setdefault(interface, []).append(field.__name__) field.set(adapter, newvalue) -- 1.7.1 On Tue, 2011-02-15 at 13:25 +0100, Hanno Schlichting wrote:
On Tue, Feb 15, 2011 at 1:21 PM, Johannes Raggam <raggam-nl@adm.at> wrote:
while - IMO - zope.schema throws that error justifiably, i think zope.formlib should handle it more gracefully in setUpEditWidgets. i think, this error comes with every schema upgrade for zope.formlib based edit-forms. so, what do you think of following patch?
The usual approach is to add new attributes as class attributes to the persistent object. Or write an actual database upgrade step, either via something like zope.generations or with a GenericSetup upgrade step.
But for zope.formlib it make indeed make sense to be more lenient here. So +0 on your patch.
Hanno
-- johannes raggam / thet python plone zope development http://johannes.raggam.co.at/ mailto:johannes@raggam.co.at http://bluedynamics.com/