No support for a list of reference fields

[ttiimmaahh]

Firestore supports the ability to create an array (list) of reference fields. I'm not 100% sure if this is a limitation of the google firestore library or if its on the fireo side, but I'm unable to do that via code. I'm able to do it manually via the GCP console, but querying all of the objects fails just as it does when trying to create that object scenario.

Has anyone come across this before?

` class MyFirstModel(Model): field1 = TextField() field2 = TextField()

class MySecondModel(Model): field1 = TextField() field2 = ListField(ReferenceField(MyFirstModel))`

[maazullah96]

Hi @ttiimmaahh I am also trying List of Reference Fields and getting the error .Did you got any solution for it ? TypeError: ('Cannot convert to a Firestore Value', <__main__.Keyword object at 0x00000210CDD8F7F0>, 'Invalid type', <class '__main__.Keyword'>)

[AxeemHaider]

If ListField is not fullfil your requirement then you can extend it Create Custom Field You can also use Base Field

[ADR-007]

Hi! I implemented it in the next way:

class TypedListField(ListField):
    allowed_attributes = ['nested_field']
    nested_field: Field

    def __init__(self, nested_field, *args, **kwargs):
        if not isinstance(nested_field, Field):
            raise AttributeTypeError('"nested_field" must be an instance of "Field".')

        super().__init__(*args, **kwargs, nested_field=nested_field)

    def contribute_to_model(self, model_cls, name):
        super().contribute_to_model(model_cls, name)
        self.raw_attributes['nested_field'].name = name
        self.raw_attributes['nested_field'].model_cls = model_cls

    def attr_nested_field(self, attr_val, field_val):
        return field_val

    def db_value(self, val: list[Any] | None) -> list[Any] | None:
        """Serialize using nested field."""
        serialized = super().db_value(val)
        if serialized is not None:
            serialized = [
                self.raw_attributes['nested_field'].db_value(item)
                for item in serialized
            ]

        return serialized

    def field_value(self, val: list[Any] | None) -> list[Any] | None:
        """Deserialize enum from value"""
        parsed = super().field_value(val)

        if parsed is not None:
            parsed = [
                self.raw_attributes['nested_field'].field_value(item)
                for item in parsed
            ]

        return parsed

But I would prefer to have it out of the box... I can create PR with changes to original ListField

[ADR-007]

And list of models:

class NestedListField(ListField):
    allowed_attributes = ['nested_model_class']
    nested_model_class: Model

    def __init__(self, nested_model_class, *args, **kwargs):
        if not issubclass(nested_model_class, Model):
            raise AttributeTypeError('"nested_model_class" must be a subclass of "Model".')

        super().__init__(*args, **kwargs, nested_model_class=nested_model_class)

    def attr_nested_model_class(self, attr_val, field_val):
        return field_val

    def get_value(self, val, ignore_required=False, ignore_default=False):
        items: list[Model] = super().get_value(val, ignore_required, ignore_default)

        results = []
        for item in items:
            item_dict = {}
            for nested_field in self.raw_attributes['nested_model_class']._meta.field_list.values():
                nested_field: Field
                nested_field_value = getattr(item, nested_field.name)
                value = nested_field.get_value(nested_field_value, ignore_required, ignore_default)
                if value is not None:
                    item_dict[nested_field.db_column_name] = value

            results.append(item_dict)

        return results

    def field_value(self, val):
        parsed = super().field_value(val)

        if not parsed:
            return parsed

        parsed = [
            ModelWrapper.from_query_result(
                self.raw_attributes['nested_model_class'](),
                item,
                True,
            )
            for item in parsed
        ]

        return parsed

[AxeemHaider]

Thanks for this implementation. PR are welcomes, You can create a PR

[ADR-007]

Here is the PR :)

I'm also going to change implementation of NestedModel to allow it to use inside ListField and do some other minor changes