feat: initial release

src/wutta_continuum/conf.py

@@ -0,0 +1,118 @@
+# -*- coding: utf-8; -*-
+################################################################################
+#
+#  Wutta-Continuum -- SQLAlchemy Versioning for WuttJamaican
+#  Copyright © 2024 Lance Edgar
+#
+#  This file is part of Wutta Framework.
+#
+#  Wutta Framework is free software: you can redistribute it and/or modify it
+#  under the terms of the GNU General Public License as published by the Free
+#  Software Foundation, either version 3 of the License, or (at your option) any
+#  later version.
+#
+#  Wutta Framework is distributed in the hope that it will be useful, but
+#  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+#  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+#  more details.
+#
+#  You should have received a copy of the GNU General Public License along with
+#  Wutta Framework.  If not, see <http://www.gnu.org/licenses/>.
+#
+################################################################################
+"""
+App Configuration
+"""
+
+import datetime
+import socket
+
+from sqlalchemy.orm import configure_mappers
+from sqlalchemy_continuum import make_versioned
+from sqlalchemy_continuum.plugins import Plugin
+
+from wuttjamaican.conf import WuttaConfigExtension
+from wuttjamaican.util import load_object
+
+
+class WuttaContinuumConfigExtension(WuttaConfigExtension):
+    """
+    App :term:`config extension` for Wutta-Continuum.
+
+    This adds a startup hook, which can optionally turn on the
+    SQLAlchemy-Continuum versioning features for the main app DB.
+    """
+    key = 'wutta_continuum'
+
+    def startup(self, config):
+        """ """
+        # only do this if config enables it
+        if not config.get_bool('wutta_continuum.enable_versioning',
+                               usedb=False, default=False):
+            return
+
+        # create wutta plugin, to assign user and ip address
+        spec = config.get('wutta_continuum.wutta_plugin_spec',
+                          usedb=False,
+                          default='wutta_continuum.conf:WuttaContinuumPlugin')
+        WuttaPlugin = load_object(spec)
+
+        # tell sqlalchemy-continuum to do its thing
+        make_versioned(plugins=[WuttaPlugin()])
+
+        # nb. must load the model before configuring mappers
+        app = config.get_app()
+        model = app.model
+
+        # tell sqlalchemy to do its thing
+        configure_mappers()
+
+
+class WuttaContinuumPlugin(Plugin):
+    """
+    SQLAlchemy-Continuum manager plugin for Wutta-Continuum.
+
+    This tries to assign the current user and IP address to the
+    transaction.
+
+    It will assume the "current machine" IP address, which may be
+    suitable for some apps but not all (e.g. web apps, where IP
+    address should reflect an arbitrary client machine).
+
+    However it does not actually have a way to determine the current
+    user.  WuttaWeb therefore uses a different plugin, based on this
+    one, to get both the user and IP address from current request.
+
+    You can override this to use a custom plugin for this purpose; if
+    so you must specify in your config file:
+
+    .. code-block:: ini
+
+       [wutta_continuum]
+       wutta_plugin_spec = poser.db.continuum:PoserContinuumPlugin
+
+    See also the SQLAlchemy-Continuum docs for
+    :doc:`sqlalchemy-continuum:plugins`.
+    """
+
+    def get_remote_addr(self, uow, session):
+        """ """
+        host = socket.gethostname()
+        return socket.gethostbyname(host)
+
+    def get_user_id(self, uow, session):
+        """ """
+
+    def transaction_args(self, uow, session):
+        """ """
+        kwargs = {}
+
+        remote_addr = self.get_remote_addr(uow, session)
+        if remote_addr:
+            kwargs['remote_addr'] = remote_addr
+
+        user_id = self.get_user_id(uow, session)
+        if user_id:
+            kwargs['user_id'] = user_id
+
+        return kwargs