[BUG] Type checker does not recognize fields on ModelSchema Meta

[Tragio]

Describe the bug
Hi there! 😃 When using a ModelSchema with a Meta class that defines the model and fields, the type checker does not recognize the fields defined in the Meta class.

Code Example

class PhoneNumberSchema(ModelSchema):
    class Meta:
        model = PhoneNumber
        fields = ["dial_code", "phone_number"]

    @http_post(
        "/test",
        auth=None,
        response={status.HTTP_201_CREATED: None},
    )
    def test(self, request, payload: PhoneNumberSchema):
        print(payload.dial_code)

Pylance outputs:

Cannot access attribute "dial_code" for class "PhoneNumberSchema"
  Attribute "dial_code" is unknownPylance[reportAttributeAccessIssue](https://github.com/microsoft/pyright/blob/main/docs/configuration.md#reportAttributeAccessIssue)

However, if I do the following, I have no problems, but then I'm repeating code.

class PhoneNumberSchema(ModelSchema):
    dial_code: Optional[str] = Field(None, max_length=10)
    class Meta:
        model = PhoneNumber
        fields = ["dial_code", "phone_number"]

Not sure if there is a better way, or if I'm doing something wrong 🤔

Thank you for the incredible work and have an amazing new year 🚀

[vitalik]

there are few concerns in your code

• def test(self, you are using class methods instead of python function and it's not clear what 'http_post` is in your case
• missing PhoneNumber model - maybe dial_code is a special field or somehitng

so no way to debug or find any reasons

[Tragio]

Hi @vitalik 👋

Sorry, you're absolutely right. 🙏 Here is the complete context that I forgot to add on my initial post.

I'm using Django Ninja Extra, where it has the @api_controller it is so seamless that I forget it is a different package. 😅 However, I also tested using only Django Ninja and the result was the same, here is the test file I used.

from ninja import ModelSchema, NinjaAPI
from ninja_extra import (
    api_controller,
    http_get,
)
from tenant.models.user import UserStubPhoneNumber

api = NinjaAPI()


class PhoneNumberSchema(ModelSchema):
    class Meta:
        model = UserStubPhoneNumber
        fields = ["dial_code", "phone_number"]


# Django Ninja Extra
@api_controller("/users", tags=["User"])
class UserAPI:
    @http_get("/test", response=PhoneNumberSchema)
    def test(self, request, payload: PhoneNumberSchema):
        print(payload.dial_code)


# Django Ninja
@api.get("/test", response=PhoneNumberSchema)
def test(request, data: PhoneNumberSchema):
    print(data.dial_code)

Thank you very much 😃

[pinguin999]

Hi @Tragio

here is an example how I worked around the problem:

class UserBodySchema(ModelSchema):
    if TYPE_CHECKING:
        date: datetime_date
        belly: Decimal
        waist: Decimal
        hip: Decimal

    class Meta:
        model = UserBody
        fields = [
            "date",
            "belly",
            "waist",
            "hip",
        ]

It's not perfect but it's working.