Bug fix: unhandled exception during AjaxSelect load

[diskream]

There is an unhandled exception in AjaxSelect2Widget after any exception in model_view.insert_model.

The error occurs when you pick something in the Ajax select box and there is an exception in the overridden insert_model method. Here is a part of the traceback:

  File "/Users/diskream/Library/Caches/pypoetry/virtualenvs/aMY0E6K2-py3.12/lib/python3.12/site-packages/sqladmin/widgets.py", line 57, in __call__
    data = field.loader.format(field.data)
           │     │      │      │     └ <property object at 0x110181300>
           │     │      │      └ <sqladmin.fields.AjaxSelectField object at 0x110903b90>
           │     │      └ <function QueryAjaxModelLoader.format at 0x1101089a0>
           │     └ <sqladmin.ajax.QueryAjaxModelLoader object at 0x1101a0b30>
           └ <sqladmin.fields.AjaxSelectField object at 0x110903b90>
  File "/Users/diskream/Library/Caches/pypoetry/virtualenvs/aMY0E6K2-py3.12/lib/python3.12/site-packages/sqladmin/ajax.py", line 59, in format
    return {"id": str(get_object_identifier(model)), "text": str(model)}
                      │                     │                    └ '1'
                      │                     └ '1'
                      └ <function get_object_identifier at 0x110108360>
  File "/Users/diskream/Library/Caches/pypoetry/virtualenvs/aMY0E6K2-py3.12/lib/python3.12/site-packages/sqladmin/helpers.py", line 183, in get_object_identifier
    primary_keys = get_primary_keys(obj)
                   │                └ '1'
                   └ <function get_primary_keys at 0x1101082c0>
  File "/Users/diskream/Library/Caches/pypoetry/virtualenvs/aMY0E6K2-py3.12/lib/python3.12/site-packages/sqladmin/helpers.py", line 178, in get_primary_keys
    return tuple(inspect(model).mapper.primary_key)
                 │       └ '1'
                 └ <function inspect at 0x106b33f60>
  File "/Users/diskream/Library/Caches/pypoetry/virtualenvs/aMY0E6K2-py3.12/lib/python3.12/site-packages/sqlalchemy/inspection.py", line 147, in inspect
    raise exc.NoInspectionAvailable(
          │   └ <class 'sqlalchemy.exc.NoInspectionAvailable'>
          └ <module 'sqlalchemy.exc' from '/Users/diskream/Library/Caches/pypoetry/virtualenvs/aMY0E6K2-py3.12/lib/python3.1...

sqlalchemy.exc.NoInspectionAvailable: No inspection system is available for object of type <class 'str'>

As you can see, the widget receives a string from the form, not the model. A common approach is to handle exceptions at the time of parsing the form.

Here is snippet to reproduce error:

from typing import Any

from sqlalchemy import Column, Integer, ForeignKey, String
from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine
from sqlalchemy.orm import declarative_base, sessionmaker, relationship
from starlette.applications import Starlette
from starlette.requests import Request

from sqladmin import Admin, ModelView

async_engine = create_async_engine("sqlite+aiosqlite:///test.db")

Base = declarative_base()  # type: Any
session_maker = sessionmaker(bind=async_engine, class_=AsyncSession, expire_on_commit=False)

app = Starlette()


@app.on_event("startup")
async def startup() -> None:
    async with async_engine.begin() as conn:
        await conn.run_sync(Base.metadata.create_all)


admin = Admin(app=app, engine=async_engine)


class User(Base):
    __tablename__ = "users"

    id = Column(Integer, primary_key=True)
    name = Column(String(length=16))

    addresses = relationship("Address", back_populates="user")

    def __str__(self) -> str:
        return f"User {self.id}"


class Address(Base):
    __tablename__ = "addresses"

    id = Column(Integer, primary_key=True)
    user_id = Column(Integer, ForeignKey("users.id"))

    user = relationship("User", back_populates="addresses")

    def __str__(self) -> str:
        return f"Address {self.id}"


class UserAdmin(ModelView, model=User):
    form_columns = ("name",)
    form_ajax_refs = {
        "addresses": {
            "fields": ("id",),
        }
    }


class AddressAdmin(ModelView, model=Address):
    form_ajax_refs = {
        "user": {
            "fields": ("name",),
            "order_by": ("id"),
        }
    }

    async def insert_model(self, request: Request, data: dict) -> Any:
        1 / 0


admin.add_view(UserAdmin)
admin.add_view(AddressAdmin)

if __name__ == "__main__":
    import uvicorn

    uvicorn.run(app, host="127.0.0.1", port=8000)

[aminalaee]

Thanks for the PR, I have a question since there's no issue related to this.

[diskream]

Thanks for the PR, I have a question since there's no issue related to this.

I decided to make a PR, not issue because I already have some workaround about it and provided snippet to reproduce. Should I have created an issue first?

[aminalaee]

Sorry I think my comment was discarded, my question was that how is this going to fix or workaround the issue?
This will just ignore the exception right?

[diskream]

Yes, my solution is to clear ajax field if there is any error on field loading. May be this is not the best solution, but due to there was no exception handling, I think there is no need to do something more serious here.