Set a default meta/config for all my classes

[bramp]

I have dozens of dataclass classes, and I'd like to set raise_on_unknown_json_key = True on all of them. Is there a way for me to configure this centrally for my application, so I don't need to add this field to every class?

[rnag]

Hi @bramp! Yes — you can achieve this by defining a shared base class with the desired Meta configuration, and then subclassing it for each of your dataclasses. This lets you centralize the configuration without repeating it on every class.

Here’s a simple example using the v1 opt-in:

from dataclasses import dataclass
from datetime import datetime
from uuid import UUID
from pprint import pp

from dataclass_wizard import JSONWizard, LoadMeta, fromdict


class BaseConfig(JSONWizard):
    class _(JSONWizard.Meta):
        v1 = True
        v1_on_unknown_key = 'RAISE'


@dataclass
class ProfileModel(BaseConfig):
    id: UUID
    name: str
    created_at: datetime


profile_json_msg = {
    "profileId": "123e4567-e89b-12d3-a456-426614174000",
    "name": "John Doe",
    "createdAt": "2021-01-01T00:00:00Z",
    "extra_key": "not mapped to a field!",
}


LoadMeta(
    v1=True,
    v1_case="AUTO",   # older versions used `v1_key_case`
    v1_field_to_alias={
        "id": "profileId",
    },
).bind_to(ProfileModel)

profile = fromdict(ProfileModel, profile_json_msg)
pp(profile)

Raises an error when subclassing BaseConfig:

dataclass_wizard.errors.UnknownKeysError: One or more JSON keys are not mapped to the dataclass schema for class `ProfileModel`.
  Unknown key: {'extra_key'}
  Dataclass fields: ['id', 'name', 'created_at']
  Input JSON object: {"profileId": "123e4567-e89b-12d3-a456-426614174000", "name": "John Doe", "createdAt": "2021-01-01T00:00:00Z", "extra_key": "not mapped to a field!"}

Let me know if this solves your use case. Thanks!

[bramp]

Oh so obvious! Thanks.