[BUG] static resolver fields called twice

[dusty-phillips]

Describe the bug

Roughly following https://django-ninja.dev/guides/response/django-pydantic/ I am seeing static resolvers called twice, once with the Django model and once with the Pydantic Schema. Consider this schema:

class UserSchema(ModelSchema):
    both: str

    class Meta:
        model = User
        fields = ["username", "email"]

    @staticmethod
    def resolve_both(obj):
        print("called with", obj, obj.__class__)
        return f"{obj.username} <{obj.email}>"


@api.get("/hello", response=UserSchema)
def hello(request):
    user = User.objects.first()
    return UserSchema.from_orm(user)

The console output is:

called with me <class 'django.contrib.auth.models.User'>
called with both='me <[email protected]>' username='me' email='[email protected]' <class 'myproject.api.UserSchema'>

My guess is the function gets called by Django-ninja and then gets called again by Pydantic, because the name is overloaded. This doesn't seem to be expected/intended. The only way I can see to fix it in my code is to scatter isinstance calls in all my resolvers.

Versions (please complete the following information):

• Python version: 3.12
• Django version: tried with 5.1.3 and 4.2.15
• Django-Ninja version: 1.3.0
• Pydantic version: tried with 2.10.1 and 2.8.2

[Houet]

Not sure if this is still relevant but you don't need the last line, that why it's called twice, you can directly return your user

class UserSchema(ModelSchema):
    both: str

    class Meta:
        model = User
        fields = ["username", "email"]

    @staticmethod
    def resolve_both(obj):
        print("called with", obj, obj.__class__)
        return f"{obj.username} <{obj.email}>"


@api.get("/hello", response=UserSchema)
def hello(request):
    return User.objects.first()

You can return the object / queryset directly, django-ninja will take care of the validation / serialization
e.g: in the documentation :

from typing import List

@api.get("/employees", response=List[EmployeeOut])
def list_employees(request):
   qs = Employee.objects.all()
   return qs