Re: Automatically Triggering post_settattr After Value Assign by _*_default Method

On Thu, Jul 17, 2008 at 8:02 PM, David C. Morrill
<dmorrill@...> wrote:
> Alexander Michael wrote:
>> If have a TraitType with a post_setattr method. Is there a way to
>> indicate that I would like the post_setattr to be called when the
>> value is set by a default method?
>
> I don't think you need to indicate anything, it should just happen. I
> you observe otherwise, please let me know...

Hmm. Here's my example:

import enthought.traits.api as traits

class MyData(traits.HasTraits):
    pass

class MyObject(traits.HasTraits):
    data = traits.Dict(traits.Str, traits.Instance(MyData))

class MyObjectDataTrait(traits.BaseInstance):
    def __init__(self, **metadata):
        super(MyObjectDataTrait, self).__init__(MyData,
            allow_none=True,
            **metadata
        )

    def validate(self, object, name, value):
        if (isinstance(object, MyObject)
          and isinstance(value, MyData)):
            return value
        self.error(object, name, value)

    def post_setattr(self, object, name, value):
        print 'post_setattr', object, name, value
        object.data[name] = value

class MyDerivedObject(MyObject):
    my_data = MyObjectDataTrait

    def _my_data_default(self):
        print '_my_data_default'
        return MyData()

obj = MyDerivedObject()
print obj.my_data # post_setattr isn't executed
#obj.my_data = MyData() # post_setattr is executed

Should this work? My svn rev may be a few weeks old, I'll refresh it.

Thanks,
Alex