def __init__(
self,
manager: "RelationsManager",
type_: RelationType,
field_name: str,
to: Type["T"],
through: Type["T"] = None,
) -> None:
"""
Initialize the Relation and keep the related models either as instances of
passed Model, or as a RelationProxy which is basically a list of models with
some special behavior, as it exposes QuerySetProxy and allows querying the
related models already pre filtered by parent model.
:param manager: reference to relation manager
:type manager: RelationsManager
:param type_: type of the relation
:type type_: RelationType
:param field_name: name of the relation field
:type field_name: str
:param to: model to which relation leads to
:type to: Type[Model]
:param through: model through which relation goes for m2m relations
:type through: Type[Model]
"""
self.manager = manager
self._owner: "Model" = manager.owner
self._type: RelationType = type_
self._to_remove: Set = set()
self.to: Type["T"] = to
self._through: Optional[Type["T"]] = through
self.field_name: str = field_name
self.related_models: Optional[Union[RelationProxy, "T"]] = (
RelationProxy(relation=self, type_=type_, field_name=field_name) if
type_ in (RelationType.REVERSE, RelationType.MULTIPLE) else None)
def _clean_related(self) -> None:
cleaned_data = [
x for i, x in enumerate(self.related_models) # type: ignore
if i not in self._to_remove
]
self.related_models = RelationProxy(
relation=self,
type_=self._type,
field_name=self.field_name,
data_=cleaned_data,
)
relation_name = self._owner.resolve_relation_name(self._owner, self.to)
self._owner.__dict__[relation_name] = cleaned_data
self._to_remove = set()
def __init__(
self,
manager: "RelationsManager",
type_: RelationType,
to: Type["T"],
through: Type["T"] = None,
) -> None:
self.manager = manager
self._owner: "Model" = manager.owner
self._type: RelationType = type_
self.to: Type["T"] = to
self.through: Optional[Type["T"]] = through
self.related_models: Optional[Union[RelationProxy, "T"]] = (
RelationProxy(
relation=self) if type_ in (RelationType.REVERSE,
RelationType.MULTIPLE) else None)
def _clean_related(self) -> None:
"""
Removes dead weakrefs from RelationProxy.
"""
cleaned_data = [
x for i, x in enumerate(self.related_models) # type: ignore
if i not in self._to_remove
]
self.related_models = RelationProxy(
relation=self,
type_=self._type,
field_name=self.field_name,
data_=cleaned_data,
)
relation_name = self.field_name
self._owner.__dict__[relation_name] = cleaned_data
self._to_remove = set()