id_: None | BaseModelId
cache_: dict[BaseModelId, Self]
to_search: list[str] = []
+ can_create_by_id = False
_exists = True
def __init__(self, id_: BaseModelId | None) -> None:
def _get_cached(cls: type[BaseModelInstance],
id_: BaseModelId) -> BaseModelInstance | None:
"""Get object of id_ from class's cache, or None if not found."""
- # pylint: disable=consider-iterating-dictionary
cache = cls.get_cache()
- if id_ in cache.keys():
+ if id_ in cache:
obj = cache[id_]
assert isinstance(obj, cls)
return obj
return obj
@classmethod
- def by_id(cls, db_conn: DatabaseConnection,
- id_: BaseModelId | None,
- # pylint: disable=unused-argument
- create: bool = False) -> Self:
+ def by_id(cls, db_conn: DatabaseConnection, id_: BaseModelId) -> Self:
"""Retrieve by id_, on failure throw NotFoundException.
First try to get from cls.cache_, only then check DB; if found,
put into cache.
-
- If create=True, make anew (but do not cache yet).
"""
obj = None
if id_ is not None:
break
if obj:
return obj
- if create:
- obj = cls(id_)
- return obj
raise NotFoundException(f'found no object of ID {id_}')
+ @classmethod
+ def by_id_or_create(cls, db_conn: DatabaseConnection,
+ id_: BaseModelId | None
+ ) -> Self:
+ """Wrapper around .by_id, creating (not caching/saving) if not find."""
+ if not cls.can_create_by_id:
+ raise HandledException('Class cannot .by_id_or_create.')
+ if id_ is None:
+ return cls(None)
+ try:
+ return cls.by_id(db_conn, id_)
+ except NotFoundException:
+ return cls(id_)
+
@classmethod
def all(cls: type[BaseModelInstance],
db_conn: DatabaseConnection) -> list[BaseModelInstance]: