incorporate PR feedback; create_table -> table_exists

Author: jlgoolsbee

docs/config_reference.rst

@@ -175,11 +175,11 @@ SqlAlchemy
 
    Default: ``'sessions'``
 
-.. py:data:: SESSION_SQLALCHEMY_CREATE_TABLE
+.. py:data:: SESSION_SQLALCHEMY_TABLE_EXISTS
     
-   Whether (or not) Flask-Session should manage creation of the table for storing session data.
+   Whether (or not) the table for storing session data is managed by libraries (e.g. Flask-Migrate) or other means outside of Flask-Session. When set to ``True``, Flask-Session will not try to create the session table.
 
-   Default: ``True``
+   Default: ``False``
 
 .. py:data:: SESSION_SQLALCHEMY_SEQUENCE
     

src/flask_session/__init__.py

@@ -91,8 +91,8 @@ def _get_interface(self, app):
         SESSION_SQLALCHEMY_TABLE = config.get(
             "SESSION_SQLALCHEMY_TABLE", Defaults.SESSION_SQLALCHEMY_TABLE
         )
-        SESSION_SQLALCHEMY_CREATE_TABLE = config.get(
-            "SESSION_SQLALCHEMY_CREATE_TABLE", Defaults.SESSION_SQLALCHEMY_CREATE_TABLE
+        SESSION_SQLALCHEMY_TABLE_EXISTS = config.get(
+            "SESSION_SQLALCHEMY_TABLE_EXISTS", Defaults.SESSION_SQLALCHEMY_TABLE_EXISTS
         )
         SESSION_SQLALCHEMY_SEQUENCE = config.get(
             "SESSION_SQLALCHEMY_SEQUENCE", Defaults.SESSION_SQLALCHEMY_SEQUENCE
@@ -185,7 +185,7 @@ def _get_interface(self, app):
                 **common_params,
                 client=SESSION_SQLALCHEMY,
                 table=SESSION_SQLALCHEMY_TABLE,
-                create_table=SESSION_SQLALCHEMY_CREATE_TABLE,
+                table_exists=SESSION_SQLALCHEMY_TABLE_EXISTS,
                 sequence=SESSION_SQLALCHEMY_SEQUENCE,
                 schema=SESSION_SQLALCHEMY_SCHEMA,
                 bind_key=SESSION_SQLALCHEMY_BIND_KEY,

src/flask_session/defaults.py

@@ -39,7 +39,7 @@ class Defaults:
     SESSION_SQLALCHEMY_SEQUENCE = None
     SESSION_SQLALCHEMY_SCHEMA = None
     SESSION_SQLALCHEMY_BIND_KEY = None
-    SESSION_SQLALCHEMY_CREATE_TABLE = True
+    SESSION_SQLALCHEMY_TABLE_EXISTS = False
 
     # DynamoDB settings
     SESSION_DYNAMODB = None

src/flask_session/sqlalchemy/sqlalchemy.py

@@ -1,3 +1,5 @@
+"""Provides a Session Interface to SQLAlchemy"""
+
 import warnings
 from datetime import datetime
 from datetime import timedelta as TimeDelta
@@ -54,11 +56,15 @@ class SqlAlchemySessionInterface(ServerSideSessionInterface):
     :param sid_length: The length of the generated session id in bytes.
     :param serialization_format: The serialization format to use for the session data.
     :param table: The table name you want to use.
+    :param table_exists: Whether the session table is created/managed outside of Flask-Session (default=False).
     :param sequence: The sequence to use for the primary key if needed.
     :param schema: The db schema to use.
     :param bind_key: The db bind key to use.
     :param cleanup_n_requests: Delete expired sessions on average every N requests.
 
+    .. versionadded:: 0.9
+        The `table_exists` parameter was added.
+
     .. versionadded:: 0.7
         db changed to client to be standard on all session interfaces.
         The `cleanup_n_request` parameter was added.
@@ -86,7 +92,7 @@ def __init__(
         sequence: Optional[str] = Defaults.SESSION_SQLALCHEMY_SEQUENCE,
         schema: Optional[str] = Defaults.SESSION_SQLALCHEMY_SCHEMA,
         bind_key: Optional[str] = Defaults.SESSION_SQLALCHEMY_BIND_KEY,
-        create_table: bool = Defaults.SESSION_SQLALCHEMY_CREATE_TABLE,
+        table_exists: bool = Defaults.SESSION_SQLALCHEMY_TABLE_EXISTS,
         cleanup_n_requests: Optional[int] = Defaults.SESSION_CLEANUP_N_REQUESTS,
     ):
         self.app = app
@@ -104,9 +110,9 @@ def __init__(
         self.sql_session_model = create_session_model(
             client, table, schema, bind_key, sequence
         )
-        
+
         # Optionally create the table if it does not exist
-        if create_table:
+        if not table_exists:
             with app.app_context():
                 if bind_key:
                     engine = self.client.get_engine(app, bind=bind_key)

tests/test_sqlalchemy.py

@@ -64,7 +64,7 @@ def test_database_not_created_automatically(self, app_utils):
             {
                 "SESSION_TYPE": "sqlalchemy",
                 "SQLALCHEMY_DATABASE_URI": "sqlite:///",
-                "SESSION_SQLALCHEMY_CREATE_TABLE": False,
+                "SESSION_SQLALCHEMY_TABLE_EXISTS": True,
             }
         )
         with app.app_context() and self.setup_sqlalchemy(