Files
ormar/ormar/relations/querysetproxy.py
2020-11-01 08:29:06 +01:00

104 lines
3.7 KiB
Python

from typing import Any, List, Optional, Sequence, TYPE_CHECKING, TypeVar, Union
import ormar
if TYPE_CHECKING: # pragma no cover
from ormar.relations import Relation
from ormar.models import Model
from ormar.queryset import QuerySet
T = TypeVar("T", bound=Model)
class QuerysetProxy(ormar.QuerySetProtocol):
if TYPE_CHECKING: # pragma no cover
relation: "Relation"
def __init__(self, relation: "Relation") -> None:
self.relation: Relation = relation
self._queryset: Optional["QuerySet"] = None
@property
def queryset(self) -> "QuerySet":
if not self._queryset:
raise AttributeError
return self._queryset
@queryset.setter
def queryset(self, value: "QuerySet") -> None:
self._queryset = value
def _assign_child_to_parent(self, child: Optional["T"]) -> None:
if child:
owner = self.relation._owner
rel_name = owner.resolve_relation_name(owner, child)
setattr(owner, rel_name, child)
def _register_related(self, child: Union["T", Sequence[Optional["T"]]]) -> None:
if isinstance(child, list):
for subchild in child:
self._assign_child_to_parent(subchild)
else:
assert isinstance(child, ormar.Model)
self._assign_child_to_parent(child)
async def create_through_instance(self, child: "T") -> None:
queryset = ormar.QuerySet(model_cls=self.relation.through)
owner_column = self.relation._owner.get_name()
child_column = child.get_name()
kwargs = {owner_column: self.relation._owner, child_column: child}
await queryset.create(**kwargs)
async def delete_through_instance(self, child: "T") -> None:
queryset = ormar.QuerySet(model_cls=self.relation.through)
owner_column = self.relation._owner.get_name()
child_column = child.get_name()
kwargs = {owner_column: self.relation._owner, child_column: child}
link_instance = await queryset.filter(**kwargs).get() # type: ignore
await link_instance.delete()
def filter(self, **kwargs: Any) -> "QuerySet": # noqa: A003
return self.queryset.filter(**kwargs)
def select_related(self, related: Union[List, str]) -> "QuerySet":
return self.queryset.select_related(related)
async def exists(self) -> bool:
return await self.queryset.exists()
async def count(self) -> int:
return await self.queryset.count()
async def clear(self) -> int:
queryset = ormar.QuerySet(model_cls=self.relation.through)
owner_column = self.relation._owner.get_name()
kwargs = {owner_column: self.relation._owner}
return await queryset.delete(**kwargs) # type: ignore
def limit(self, limit_count: int) -> "QuerySet":
return self.queryset.limit(limit_count)
def offset(self, offset: int) -> "QuerySet":
return self.queryset.offset(offset)
async def first(self, **kwargs: Any) -> "Model":
first = await self.queryset.first(**kwargs)
self._register_related(first)
return first
async def get(self, **kwargs: Any) -> "Model":
get = await self.queryset.get(**kwargs)
self._register_related(get)
return get
async def all(self, **kwargs: Any) -> Sequence[Optional["Model"]]: # noqa: A003
all_items = await self.queryset.all(**kwargs)
self._register_related(all_items)
return all_items
async def create(self, **kwargs: Any) -> "Model":
create = await self.queryset.create(**kwargs)
self._register_related(create)
await self.create_through_instance(create)
return create