[Zope3-Users] Re: Varying Default Value for Subschema (Object in Tuple)

[Derek Richardson]

Derek Richardson wrote:
> I have a schema (the Tuple of Objects is the important part):
> 
> class ISyndications(Interface):
>     """Annotation that indicates the object can provide IFeed
>     and that stores the current syndication configuration.
>     """
> 
>     enabled = Bool(title=_(u'Enable syndication'),
>                    description=_(u'...'),
>                    default=False,
>                   )
> 
>     syndications = Tuple(title=_(u'Feeds'),
>                         description=_(u'...'),
>                         required=False,
>                         default=(),
>                         value_type=Object(title=_(u'Feed'),
>                                           description=_(u'...'),
>                                           schema=ISyndication,
>                                          ),
>                        )
> 
>     def findSyndicationByLocalURL(url):
>         """Find an ISyndication in syndications by the local URL it
>         contains.
>         """
> 
> The subschema is (the UUID field is the important part):
> 
> class ISyndication(Interface):
>     """Configuration for an individual feed.
>     """
> 
>     name = TextLine(title=_(u'Name'),
>                     description=_(u'...'),
>                    )
> 
>     format = Choice(title=_(u'Format'),
>                     description=_(u'Data format for this feed'),
>                     values=[u'atom', u'rss 1.0', u'rss 2.0'],
>                    )
> 
>     recurse = Bool(title=_(u'Recurse'),
>                    description=_(u'...'),
>                    default=False,
>                   )
> 
>     enabled = Bool(title=_(u'Enabled'),
>                    description=_(u'...'),
>                    default=True,
>                   )
> 
>     referring_URL = URI(title=_(u'URL'),
>                         description=_(u'...'),
>                        )
> 
>     local_URL = URI(title=_(u'Local URL'),
>                     description=_(u'...'),
>                    )
> 
>     UUID = TextLine(title=_(u'UUID'),
>                     description=_(u'UUID for this feed.'),
>                     required=False,
>                     readonly=True,
>                    )
> 
> I want to populate the UUID upon creation from a function. So I tried 
> this (the __init__ is the important part):
> 
> class Syndication(persistent.Persistent):
>     """See ISyndication
>     """
> 
>     implements(ISyndication, IItemUUIDable)
> 
> 
>         self.name = u''
>         self.format = u''
>         self.recurse = False
>         self.enabled = False
>         self.referring_URL = None
>         self.local_URL = None
> 
>     def __init__(self):
>         self.UUID = uuid1()
> 
> However, the UUID field does not show up in the interface as initialized 
> when I do:
> 
> class SyndicationsEditForm(EditForm):
>     """Edit form for syndications.
>     """
> 
>     form_fields = Fields(ISyndications)
> 
>     ow = CustomWidgetFactory(ObjectWidget, Syndication)
>     sw = CustomWidgetFactory(SequenceWidget, subwidget=ow)
>     form_fields['syndications'].custom_widget = sw
>     label = u'Configure syndications'
> 
> This seems like it should be an easy thing to do. Who can tell me what 
> I'm doing wrong?
> 
> Thanks,
> 
> Derek

The problem *may* stem from sequencewidget.py (lines 235-239 in Zope 3.3.1):

         # add an entry to the list if the add button has been pressed
         if self.name + ".add" in self.request.form:
             # Should this be using self.context.value_type.missing_value
             # instead of None?
             sequence.append(None)

When I hack it just to prove a point, like so:

         # add an entry to the list if the add button has been pressed
         if self.name + ".add" in self.request.form:
             # Should this be using self.context.value_type.missing_value
             # instead of None?
             from plone.syndication.syndication import Syndication
             sequence.append(Syndication())
             #sequence.append(None)

The UUID field gets populated.

But I'm not sure where to go with this. I don't see any bugs for SequenceWidget 
on launchpad, so I'm still figuring I'm doing something wrong...

Derek