initial upload

cao_blogr/models/__init__.py

@@ -0,0 +1,78 @@
+from sqlalchemy import engine_from_config
+from sqlalchemy.orm import sessionmaker
+from sqlalchemy.orm import configure_mappers
+import zope.sqlalchemy
+
+# import or define all models here to ensure they are attached to the
+# Base.metadata prior to any initialization routines
+from .user import User
+from .blog_record import BlogRecord
+
+# run configure_mappers after defining all of the models to ensure
+# all relationships can be setup
+configure_mappers()
+
+
+def get_engine(settings, prefix='sqlalchemy.'):
+    return engine_from_config(settings, prefix)
+
+
+def get_session_factory(engine):
+    factory = sessionmaker()
+    factory.configure(bind=engine)
+    return factory
+
+
+def get_tm_session(session_factory, transaction_manager):
+    """
+    Get a ``sqlalchemy.orm.Session`` instance backed by a transaction.
+
+    This function will hook the session to the transaction manager which
+    will take care of committing any changes.
+
+    - When using pyramid_tm it will automatically be committed or aborted
+      depending on whether an exception is raised.
+
+    - When using scripts you should wrap the session in a manager yourself.
+      For example::
+
+          import transaction
+
+          engine = get_engine(settings)
+          session_factory = get_session_factory(engine)
+          with transaction.manager:
+              dbsession = get_tm_session(session_factory, transaction.manager)
+
+    """
+    dbsession = session_factory()
+    zope.sqlalchemy.register(
+        dbsession, transaction_manager=transaction_manager)
+    return dbsession
+
+
+def includeme(config):
+    """
+    Initialize the model for a Pyramid app.
+
+    Activate this setup using ``config.include('cao_blogr.models')``.
+
+    """
+    settings = config.get_settings()
+    settings['tm.manager_hook'] = 'pyramid_tm.explicit_manager'
+
+    # use pyramid_tm to hook the transaction lifecycle to the request
+    config.include('pyramid_tm')
+
+    # use pyramid_retry to retry a request when transient exceptions occur
+    config.include('pyramid_retry')
+
+    session_factory = get_session_factory(get_engine(settings))
+    config.registry['dbsession_factory'] = session_factory
+
+    # make request.dbsession available for use in Pyramid
+    config.add_request_method(
+        # r.tm is the transaction manager used by pyramid_tm
+        lambda r: get_tm_session(session_factory, r.tm),
+        'dbsession',
+        reify=True
+    )