from typing import TYPE_CHECKING, Any, Tuple
from django.db import models
from django.db.models import ManyToManyField
from django.utils.translation import gettext_lazy as _
from eav.logic.managers import EnumGroupManager
from eav.logic.object_pk import get_pk_format
from eav.settings import CHARFIELD_LENGTH
if TYPE_CHECKING:
from .enum_value import EnumValue
[docs]class EnumGroup(models.Model):
"""
*EnumGroup* objects have two fields - a *name* ``CharField`` and *values*,
a ``ManyToManyField`` to :class:`EnumValue`. :class:`Attribute` classes
with datatype *TYPE_ENUM* have a ``ForeignKey`` field to *EnumGroup*.
See :class:`EnumValue` for an example.
"""
objects = EnumGroupManager()
class Meta:
verbose_name = _('EnumGroup')
verbose_name_plural = _('EnumGroups')
id = get_pk_format()
name = models.CharField(
unique=True,
max_length=CHARFIELD_LENGTH,
verbose_name=_('Name'),
)
values: "ManyToManyField[EnumValue, Any]" = ManyToManyField(
"eav.EnumValue",
verbose_name=_('Enum group'),
)
def __str__(self) -> str:
"""String representation of `EnumGroup` instance."""
return str(self.name)
def __repr__(self) -> str:
"""String representation of `EnumGroup` object."""
return f'<EnumGroup {self.name}>'
[docs] def natural_key(self) -> Tuple[str]:
"""
Retrieve the natural key for the EnumGroup instance.
The natural key for an EnumGroup is defined by its `name`. This method
returns the name of the instance as a single-element tuple.
Returns
-------
tuple: A tuple containing the name of the EnumGroup instance.
"""
return (self.name,)
