[Product-Developers] Re: Using List or Tuple from zope.schema

[Derek Richardson]

It needs a 'value_type' parameter to designate what type the list holds. 
Look at p59 of philiKON's book (2nd ed.).

The error looks like it's trying to do multiadaption with a None for the 
second argument. This is consistent with my advice above.

Derek

Tim Hicks wrote:
> Hi,
> 
> Is it possible to use zope.schema.Tuple (or .List) with plone 3?  I'm
> trying to write a portlet that effectively has a 'LinesField' (in AT
> terms) as one of its attributes.  To that end, I have::
> 
> class IFeedLinksPortlet(IPortletDataProvider):
>     """A portlet listing links to syndication feeds.
>     """
> 
>     tal_lines = schema.List(
>         title=_(u'Objects to display feeds for.'),
>         description=_(u"TAL statements referring to objects to display
> feeds for."),
>         required=True,
>         default=['context',])
> 
> 
> However, when I try to add my portlet, I get the traceback pasted below.
>  Any idea how to get through this?
> 
> Thanks,
> 
> 
> Tim
> 
> 
> 2007-12-31 18:46:17 ERROR Zope.SiteErrorLog
> http://localhost:8080/test/plone/++c
> ontextportlets++plone.leftcolumn/+/plone.app.syndication.outbound.portlets.FeedLinks
> Traceback (innermost last):
>   Module ZPublisher.Publish, line 119, in publish
>   Module ZPublisher.mapply, line 88, in mapply
>   Module ZPublisher.Publish, line 42, in call_object
>   Module plone.app.portlets.browser.formhelper, line 53, in __call__
>   Module zope.formlib.form, line 769, in __call__
>   Module Products.Five.formlib.formbase, line 55, in update
>   Module zope.formlib.form, line 732, in update
>   Module zope.formlib.form, line 856, in setUpWidgets
>   Module zope.formlib.form, line 302, in setUpInputWidgets
>   Module zope.formlib.form, line 323, in _createWidget
>   Module zope.component._api, line 101, in getMultiAdapter
>   Module zope.component._api, line 114, in queryMultiAdapter
>   Module zope.component.registry, line 206, in queryMultiAdapter
>   Module zope.interface.adapter, line 482, in queryMultiAdapter
>   Module zope.app.component.metaconfigure, line 160, in __call__
>   Module zope.app.form.browser.itemswidgets, line 56, in
> CollectionInputWidget
>   Module zope.component._api, line 103, in getMultiAdapter
> ComponentLookupError: ((<zope.schema._field.List object at 0x06017510>,
> None, <HTTPRequest,
> URL=http://localhost:8080/test/plone/++contextportlets++plone.leftcolumn/+/plone.app.syndication.outbound.portlets.FeedLinks>),
> <InterfaceClass zope.app.form.interfaces.IInputWidget>, u'')