[Zope3-Users] Set & List constraints

[Markus Kemmerling]

Am 10.07.2008 um 16:44 schrieb Tim Cook:

> When constraining the membership of zope.schema List and Set; is it
> valid to say that this will work:
>
>
> value=List(
>   title=u"Value",
>   constraint=classProvides(IMyClass)
> )
>
>
> where IMyClass defines the schema for the MyClass and is the only
> objects allowed in the List?

I would rather say:

value=List(
   title=u"Value",
   value_type=Object(schema=IMyClass)
)

Anyhow, such a constraint is of limited use only, since it does not  
prevent you from adding any object you like to the list *after* it  
got assigned to the 'value' attribute.

Regards,
Markus Kemmerling