feat: enable flask support (#86)

The PR enables Flask support by changing how we validate the session object.

In normal Sessions, the `bind` attribute is never empty. However, when using scoped sessions, this is intended to be empty.  This change will call the `get_bind()` function when the bind is not set.

advanced_alchemy/repository/_async.py

@@ -92,12 +92,7 @@ def __init__(
             self.statement = lambda_stmt(lambda: statement)
         else:
             self.statement = statement
-        if not self.session.bind:
-            # this shouldn't actually ever happen, but we include it anyway to properly
-            # narrow down the types
-            msg = "Session improperly configure"
-            raise ValueError(msg)
-        self._dialect = self.session.bind.dialect
+        self._dialect = self.session.bind.dialect if self.session.bind is not None else self.session.get_bind().dialect
         self._prefer_any = any(self._dialect.name == engine_type for engine_type in self.prefer_any_dialects or ())
 
     @classmethod

advanced_alchemy/repository/_sync.py

@@ -93,12 +93,7 @@ def __init__(
             self.statement = lambda_stmt(lambda: statement)
         else:
             self.statement = statement
-        if not self.session.bind:
-            # this shouldn't actually ever happen, but we include it anyway to properly
-            # narrow down the types
-            msg = "Session improperly configure"
-            raise ValueError(msg)
-        self._dialect = self.session.bind.dialect
+        self._dialect = self.session.bind.dialect if self.session.bind is not None else self.session.get_bind().dialect
         self._prefer_any = any(self._dialect.name == engine_type for engine_type in self.prefer_any_dialects or ())
 
     @classmethod

examples/flask.py

@@ -0,0 +1,47 @@
+from flask import Flask
+from flask_sqlalchemy import SQLAlchemy
+from sqlalchemy.orm import Mapped, sessionmaker
+
+from advanced_alchemy import SQLAlchemySyncRepository
+from advanced_alchemy.base import UUIDBase
+
+SQLALCHEMY_DATABASE_URI = "sqlite:///:memory:"
+
+app = Flask(__name__)
+app.config["SQLALCHEMY_DATABASE_URI"] = SQLALCHEMY_DATABASE_URI
+db = SQLAlchemy(app)
+
+
+class Message(UUIDBase):
+    text: Mapped[str]
+
+
+class MessageRepository(SQLAlchemySyncRepository[Message]):
+    model_type = Message
+
+
+# Working
+with app.app_context():
+    with db.engine.begin() as conn:
+        Message.metadata.create_all(conn)
+
+    session = sessionmaker(db.engine)()
+
+    repo = MessageRepository(session=session)
+    repo.add(Message(text="Hello, world!"))
+
+    message = repo.list()[0]
+    assert message.text == "Hello, world!"  # noqa: S101
+
+
+# Not working
+with app.app_context():
+    with db.engine.begin() as conn:
+        Message.metadata.create_all(conn)
+
+    session = db.session
+    repo = MessageRepository(session=session)
+    repo.add(Message(text="Hello, world!"))
+
+    message = repo.list()[0]
+    assert message.text == "Hello, world!"  # noqa: S101

pyproject.toml

@@ -31,12 +31,12 @@ dependencies = [
   "greenlet; sys_platform == \"darwin\"",
 ]
 description = "Ready-to-go SQLAlchemy concoctions."
-keywords = ["sqlalchemy", "alembic", "litestar", "sanic", "fastapi"]
+keywords = ["sqlalchemy", "alembic", "litestar", "sanic", "fastapi", "flask"]
 license = {text = "MIT"}
 name = "advanced_alchemy"
 readme = "README.md"
 requires-python = ">=3.8"
-version = "0.5.2"
+version = "0.5.3"
 
 [project.urls]
 Changelog = "https://docs.advanced-alchemy.jolt.rs/latest/changelog"
@@ -89,6 +89,8 @@ extensions = [
   "sanic-testing>=23.6.0",
   "socketify>=0.0.27",
   "msgspec>=0.18.2",
+  "flask>=3.0.0",
+  "flask-sqlalchemy>=3.1.1",
 ]
 linting = [
   "pre-commit>=3.4.0",