100 lines
3.5 KiB
Python
100 lines
3.5 KiB
Python
from typing import Dict, List, Optional, Sequence, TYPE_CHECKING, Type, TypeVar, Union
|
|
from weakref import proxy
|
|
|
|
from ormar.fields import BaseField
|
|
from ormar.fields.foreign_key import ForeignKeyField
|
|
from ormar.fields.many_to_many import ManyToManyField
|
|
from ormar.relations.relation import Relation, RelationType
|
|
from ormar.relations.utils import get_relations_sides_and_names
|
|
|
|
if TYPE_CHECKING: # pragma no cover
|
|
from ormar import Model
|
|
from ormar.models import NewBaseModel
|
|
|
|
T = TypeVar("T", bound=Model)
|
|
|
|
|
|
class RelationsManager:
|
|
def __init__(
|
|
self,
|
|
related_fields: List[Type[ForeignKeyField]] = None,
|
|
owner: "NewBaseModel" = None,
|
|
) -> None:
|
|
self.owner = proxy(owner)
|
|
self._related_fields = related_fields or []
|
|
self._related_names = [field.name for field in self._related_fields]
|
|
self._relations: Dict[str, Relation] = dict()
|
|
for field in self._related_fields:
|
|
self._add_relation(field)
|
|
|
|
def _get_relation_type(self, field: Type[BaseField]) -> RelationType:
|
|
if issubclass(field, ManyToManyField):
|
|
return RelationType.MULTIPLE
|
|
return RelationType.PRIMARY if not field.virtual else RelationType.REVERSE
|
|
|
|
def _add_relation(self, field: Type[BaseField]) -> None:
|
|
self._relations[field.name] = Relation(
|
|
manager=self,
|
|
type_=self._get_relation_type(field),
|
|
field_name=field.name,
|
|
to=field.to,
|
|
through=getattr(field, "through", None),
|
|
)
|
|
|
|
def __contains__(self, item: str) -> bool:
|
|
return item in self._related_names
|
|
|
|
def get(self, name: str) -> Optional[Union["T", Sequence["T"]]]:
|
|
relation = self._relations.get(name, None)
|
|
if relation is not None:
|
|
return relation.get()
|
|
return None # pragma nocover
|
|
|
|
def _get(self, name: str) -> Optional[Relation]:
|
|
relation = self._relations.get(name, None)
|
|
if relation is not None:
|
|
return relation
|
|
return None
|
|
|
|
@staticmethod
|
|
def add(
|
|
parent: "Model",
|
|
child: "Model",
|
|
child_name: str,
|
|
virtual: bool,
|
|
relation_name: str,
|
|
) -> None:
|
|
to_field: Type[BaseField] = child.Meta.model_fields[relation_name]
|
|
# print('comming', child_name, relation_name)
|
|
(parent, child, child_name, to_name,) = get_relations_sides_and_names(
|
|
to_field, parent, child, child_name, virtual
|
|
)
|
|
|
|
# print('adding', parent.get_name(), child.get_name(), child_name)
|
|
parent_relation = parent._orm._get(child_name)
|
|
if parent_relation:
|
|
parent_relation.add(child) # type: ignore
|
|
|
|
# print('adding', child.get_name(), parent.get_name(), child_name)
|
|
child_relation = child._orm._get(to_name)
|
|
if child_relation:
|
|
child_relation.add(parent)
|
|
|
|
def remove(
|
|
self, name: str, child: Union["NewBaseModel", Type["NewBaseModel"]]
|
|
) -> None:
|
|
relation = self._get(name)
|
|
if relation:
|
|
relation.remove(child)
|
|
|
|
@staticmethod
|
|
def remove_parent(
|
|
item: Union["NewBaseModel", Type["NewBaseModel"]], name: "Model"
|
|
) -> None:
|
|
related_model = name
|
|
rel_name = item.resolve_relation_name(item, related_model)
|
|
if rel_name in item._orm:
|
|
relation_name = item.resolve_relation_name(related_model, item)
|
|
item._orm.remove(rel_name, related_model)
|
|
related_model._orm.remove(relation_name, item)
|