CRUDKit update.

crudkit/engines.py

@@ -0,0 +1,43 @@
+from __future__ import annotations
+from typing import Type, Optional
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker
+from .config import Config, get_config
+from ._sqlite import apply_sqlite_pragmas
+
+def build_engine(config_cls: Type[Config] | None = None):
+    config_cls = config_cls or get_config(None)
+    engine = create_engine(config_cls.DATABASE_URL, **config_cls.engine_kwargs())
+    apply_sqlite_pragmas(engine, config_cls.SQLITE_PRAGMAS)
+    return engine
+
+def build_sessionmaker(config_cls: Type[Config] | None = None, engine=None):
+    config_cls = config_cls or get_config(None)
+    engine = engine or build_engine(config_cls)
+    return sessionmaker(bind=engine, **config_cls.session_kwargs())
+
+class CRUDKitRuntime:
+    """
+    Lightweight container so CRUDKit can be given either:
+        - prebuild engine/sessionmaker, or
+        - a Config to build them lazily
+    """
+    def __init__(self, *, engine=None, session_factory=None, config: Optional[Type[Config]] = None):
+        if engine is None and session_factory is None and config is None:
+            config = get_config(None)
+        self._config = config
+        self._engine = engine or (build_engine(config) if config else None)
+        self._session_factory = session_factory or (build_sessionmaker(config, self._engine) if config else None)
+
+    @property
+    def engine(self):
+        if self._engine is None and self._config:
+            self._engine = build_engine(self._config)
+        return self._engine
+
+    @property
+    def session_factory(self):
+        if self._session_factory is None:
+            if self._config and self._engine:
+                self._session_factory = build_sessionmaker(self._config, self._engine)
+        return self._session_factory