db.py

# Copyright The IETF Trust 2021-2025, All Rights Reserved

import jsonfield
from django.db import models

from ietf.utils.fields import (
    IETFJSONField as FormIETFJSONField,
    EmptyAwareJSONField as FormEmptyAwareJSONField,
)


class EmptyAwareJSONField(models.JSONField):
    """JSONField that allows empty JSON values when model specifies empty=False

    Taken from/inspired by
    https://stackoverflow.com/questions/55147169/django-admin-jsonfield-default-empty-dict-wont-save-in-admin

    JSONField should recognize {}, (), and [] as valid, non-empty JSON values.

    If customizing the formfield, the field must accept the `empty_values` argument.
    """

    def __init__(
        self,
        *args,
        empty_values=FormEmptyAwareJSONField.empty_values,
        accepted_empty_values=None,
        **kwargs,
    ):
        if accepted_empty_values is None:
            accepted_empty_values = []
        self.empty_values = [x for x in empty_values if x not in accepted_empty_values]
        super().__init__(*args, **kwargs)

    def formfield(self, **kwargs):
        defaults = {
            "form_class": FormEmptyAwareJSONField,
            "empty_values": self.empty_values,
        }
        defaults.update(kwargs)
        return super().formfield(**defaults)


class IETFJSONField(jsonfield.JSONField):  # pragma: no cover
    # Deprecated - use EmptyAwareJSONField instead (different base class requires a
    # new field name)
    # Remove this class when migrations are squashed and it is no longer referenced
    form_class = FormIETFJSONField

    def __init__(
        self,
        *args,
        empty_values=FormIETFJSONField.empty_values,
        accepted_empty_values=None,
        **kwargs,
    ):
        if accepted_empty_values is None:
            accepted_empty_values = []
        self.empty_values = [x for x in empty_values if x not in accepted_empty_values]
        super().__init__(*args, **kwargs)

    def formfield(self, **kwargs):
        if "form_class" not in kwargs or issubclass(
            kwargs["form_class"], FormIETFJSONField
        ):
            kwargs.setdefault("empty_values", self.empty_values)
        return super().formfield(**{**kwargs})