Google NDB-StructuredProperty结构内的必需属性未按预期工作

Question

I have encountered an issue with the required option from ndb.Model when it is placed inside a Model specified as a structure from a StructuredProperty.

Here is the models definition :

class SubModel(ndb.Model):
    submodel_id = ndb.StringProperty(required=True)


class MyModel(ndb.Model):

    model_id = ndb.StringProperty(required = True)
    submodels = ndb.StructuredProperty(SubModel, repeated=True)

    def __init__(self, *args, **kwargs):
        super(MyModel, self).__init__(*args, **kwargs)
        if 'submodels' in kwargs.keys():
            _submodels = []
            for kwarg in kwargs['submodels']:
                if isinstance(kwarg, SubModel):
                    _submodels.append(kwarg)
                else:
                    t = SubModel(**kwarg)
                    _submodels.append(t)
            self.submodels = _submodels

What I want to do is either to create a model with no submodels or to create a model in which every submodels have a required id, otherwise, it raises an error.

So when I test this model, I get these results :

args1 = {"model_id":"some_id","submodels":[{"submodel_id":null}]}
model1 = MyModel(**args1)
model1.put()
print model1.key.id()

# Everything works while submodel_id hasn't been set and it returns the key id from Google Datastore

args2 = {"model_id":null,"submodels":[{"submodel_id":"some_id"}]}
model2 = MyModel(**args2)
model2.put()
print model2.key.id()

# Google Datastore raises an error : Entity has uninitialized properties: model_id

Is this behavior standard behavior from ndb.StructuredProperty (meaning that no property options are considered from the structure specified) or should I implement what I want to do differently ?

What I also want to do is to make Submodel inherit from ndb.Expando instead of ndb.Model but since ndb.Expando inherits from ndb.Model, that would be an even more precise question...

Answer 1

You have required = True on 'model_id'. You are trying to put() an entity without defining one ( null doesn't count).

Your put() s are on MyModel . Not sure why the submodel_id requirement in SubModel isn't being checked when putting on the parent model. Seems it should be checked. Can you check the datastore and see what has actually been put() ? When you read back that entity, what do you get?