X-Git-Url: https://plomlompom.com/repos/berlin_corona.txt?a=blobdiff_plain;f=plomtask%2Fdb.py;h=cce2630cd58bfb8bf7283c2eb0d2f45006d8ba26;hb=c021152e6566c8374170de916c69d6b5c816cd54;hp=853b4c68c65780e339b77785b961788370373648;hpb=e3bfd84f9061d5f03ec5f5764f75e4137505ea45;p=plomtask

diff --git a/plomtask/db.py b/plomtask/db.py
index 853b4c6..cce2630 100644
--- a/plomtask/db.py
+++ b/plomtask/db.py
@@ -238,6 +238,7 @@ class BaseModel(Generic[BaseModelId]):
     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:
@@ -336,9 +337,8 @@ class BaseModel(Generic[BaseModelId]):
     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
@@ -387,16 +387,11 @@ class BaseModel(Generic[BaseModelId]):
         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:
@@ -407,11 +402,22 @@ class BaseModel(Generic[BaseModelId]):
                     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]: