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- import enum
- from types import DynamicClassAttribute
-
- from django.utils.functional import Promise
-
- __all__ = ["Choices", "IntegerChoices", "TextChoices"]
-
-
- class ChoicesMeta(enum.EnumMeta):
- """A metaclass for creating a enum choices."""
-
- def __new__(metacls, classname, bases, classdict, **kwds):
- labels = []
- for key in classdict._member_names:
- value = classdict[key]
- if (
- isinstance(value, (list, tuple))
- and len(value) > 1
- and isinstance(value[-1], (Promise, str))
- ):
- *value, label = value
- value = tuple(value)
- else:
- label = key.replace("_", " ").title()
- labels.append(label)
- # Use dict.__setitem__() to suppress defenses against double
- # assignment in enum's classdict.
- dict.__setitem__(classdict, key, value)
- cls = super().__new__(metacls, classname, bases, classdict, **kwds)
- for member, label in zip(cls.__members__.values(), labels):
- member._label_ = label
- return enum.unique(cls)
-
- def __contains__(cls, member):
- if not isinstance(member, enum.Enum):
- # Allow non-enums to match against member values.
- return any(x.value == member for x in cls)
- return super().__contains__(member)
-
- @property
- def names(cls):
- empty = ["__empty__"] if hasattr(cls, "__empty__") else []
- return empty + [member.name for member in cls]
-
- @property
- def choices(cls):
- empty = [(None, cls.__empty__)] if hasattr(cls, "__empty__") else []
- return empty + [(member.value, member.label) for member in cls]
-
- @property
- def labels(cls):
- return [label for _, label in cls.choices]
-
- @property
- def values(cls):
- return [value for value, _ in cls.choices]
-
-
- class Choices(enum.Enum, metaclass=ChoicesMeta):
- """Class for creating enumerated choices."""
-
- @DynamicClassAttribute
- def label(self):
- return self._label_
-
- @property
- def do_not_call_in_templates(self):
- return True
-
- def __str__(self):
- """
- Use value when cast to str, so that Choices set as model instance
- attributes are rendered as expected in templates and similar contexts.
- """
- return str(self.value)
-
- # A similar format was proposed for Python 3.10.
- def __repr__(self):
- return f"{self.__class__.__qualname__}.{self._name_}"
-
-
- class IntegerChoices(int, Choices):
- """Class for creating enumerated integer choices."""
-
- pass
-
-
- class TextChoices(str, Choices):
- """Class for creating enumerated string choices."""
-
- def _generate_next_value_(name, start, count, last_values):
- return name
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