Python mongoengine.ReferenceField() Examples

def models():

    class HeadTeacher(me.EmbeddedDocument):
        full_name = me.StringField(max_length=255, unique=True, default='noname')

    class Course(me.Document):
        id = me.IntField(primary_key=True)
        name = me.StringField()
        # These are for better model form testing
        cost = me.IntField()
        description = me.StringField()
        level = me.StringField(choices=('Primary', 'Secondary'))
        prereqs = me.DictField()
        started = me.DateTimeField()
        grade = AnotherIntegerField()
        students = me.ListField(me.ReferenceField('Student'))

    class School(me.Document):
        name = me.StringField()
        students = me.ListField(me.ReferenceField('Student'))
        headteacher = me.EmbeddedDocumentField(HeadTeacher)

    class Student(me.Document):
        full_name = me.StringField(max_length=255, unique=True, default='noname')
        age = me.IntField(min_value=10, max_value=99)
        dob = me.DateTimeField(null=True)
        date_created = me.DateTimeField(default=dt.datetime.utcnow,
                                        help_text='date the student was created')
        current_school = me.ReferenceField('School')
        courses = me.ListField(me.ReferenceField('Course'))
        email = me.EmailField(max_length=100)
        profile_uri = me.URLField(max_length=200)

    # So that we can access models with dot-notation, e.g. models.Course
    class _models(object):

        def __init__(self):
            self.HeadTeacher = HeadTeacher
            self.Course = Course
            self.School = School
            self.Student = Student
    return _models() 

def reference_args(self):
        def get_reference_field(r, kv):
            field = kv[1]
            mongo_field = getattr(self.model, kv[0], None)
            if isinstance(
                mongo_field,
                (mongoengine.LazyReferenceField, mongoengine.ReferenceField),
            ):
                field = convert_mongoengine_field(mongo_field, self.registry)
            if callable(getattr(field, "get_type", None)):
                _type = field.get_type()
                if _type:
                    node = _type._type._meta
                    if "id" in node.fields and not issubclass(
                        node.model, (mongoengine.EmbeddedDocument,)
                    ):
                        r.update({kv[0]: node.fields["id"]._type.of_type()})
            return r

        return reduce(get_reference_field, self.fields.items(), {}) 

def convert_field_to_list(field, registry=None):
    base_type = convert_mongoengine_field(field.field, registry=registry)
    if isinstance(base_type, graphene.Field):
        return graphene.List(
            base_type._type,
            description=get_field_description(field, registry),
            required=field.required
        )
    if isinstance(base_type, (graphene.Dynamic)):
        base_type = base_type.get_type()
        if base_type is None:
            return
        base_type = base_type._type

    if graphene.is_node(base_type):
        return base_type._meta.connection_field_class(base_type)

    # Non-relationship field
    relations = (mongoengine.ReferenceField, mongoengine.EmbeddedDocumentField)
    if not isinstance(base_type, (graphene.List, graphene.NonNull)) and not isinstance(
        field.field, relations
    ):
        base_type = type(base_type)

    return graphene.List(
        base_type,
        description=get_field_description(field, registry),
        required=field.required,
    ) 

def convert_field_to_union(field, registry=None):

    _types = []
    for choice in field.choices:
        if isinstance(field, mongoengine.GenericReferenceField):
            _field = mongoengine.ReferenceField(get_document(choice))
        elif isinstance(field, mongoengine.GenericEmbeddedDocumentField):
            _field = mongoengine.EmbeddedDocumentField(choice)

        _field = convert_mongoengine_field(_field, registry)
        _type = _field.get_type()
        if _type:
            _types.append(_type.type)
        else:
            # TODO: Register type auto-matically here.
            pass

    if len(_types) == 0:
        return None

    # XXX: Use uuid to avoid duplicate name
    name = "{}_{}_union_{}".format(
        field._owner_document.__name__,
        field.db_field,
        str(uuid.uuid1()).replace("-", ""),
    )
    Meta = type("Meta", (object,), {"types": tuple(_types)})
    _union = type(name, (graphene.Union,), {"Meta": Meta})
    return graphene.Field(_union) 

def test_ReferenceField(self):
        class ReferenceDoc(me.Document):
            field = me.IntField(primary_key=True, default=42)
        class Doc(me.Document):
            id = me.StringField(primary_key=True, default='main')
            ref = me.ReferenceField(ReferenceDoc)
        fields_ = fields_for_model(Doc)
        assert type(fields_['ref']) is fields.Reference
        class DocSchema(ModelSchema):
            class Meta:
                model = Doc
        ref_doc = ReferenceDoc().save()
        doc = Doc(ref=ref_doc)
        dump = DocSchema().dump(doc)
        assert not dump.errors
        assert dump.data == {'ref': 42, 'id': 'main'}
        # Try the same with reference document type passed as string
        class DocSchemaRefAsString(Schema):
            id = fields.String()
            ref = fields.Reference('ReferenceDoc')
        dump = DocSchemaRefAsString().dump(doc)
        assert not dump.errors
        assert dump.data == {'ref': 42, 'id': 'main'}
        # Test the field loading
        load = DocSchemaRefAsString().load(dump.data)
        assert not load.errors
        assert type(load.data['ref']) == ReferenceDoc
        # Try invalid loads
        for bad_ref in (1, 'NaN', None):
            dump.data['ref'] = bad_ref
            _, errors = DocSchemaRefAsString().load(dump.data)
            assert errors, bad_ref