--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/iro/model/utils.py	Thu Sep 27 17:15:46 2012 +0200
@@ -0,0 +1,51 @@
+# Copyright (c) 2012 netzguerilla.net <iro@netzguerilla.net>
+# 
+# This file is part of Iro.
+# 
+# Permission is hereby granted, free of charge, to any person obtaining a copy of
+# this software and associated documentation files (the "Software"), to deal in
+# the Software without restriction, including without limitation the rights to use,
+# copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+# #Software, and to permit persons to whom the Software is furnished to do so,
+# subject to the following conditions:
+# 
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+# 
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+# INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+# PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+from sqlalchemy.orm import sessionmaker
+
+class WithSession(object):
+    '''a with statement for a database session connection.'''
+    def __init__(self, engine, autocommit=False):
+        """
+        :param `sqlalchemy.engine.base.Engine` engine: a valid sqlalchemy engine object (normally created via :func:`sqlalchemy.create_engine`).
+        :param boolean autocommit: autocommit after running the function.
+
+        .. automethod:: __enter__
+        .. automethod:: __exit__
+        """
+        self.engine = engine
+        self.autocommit=autocommit
+    
+    def __enter__(self):
+        """returns a vaild session object."""
+        self.session = sessionmaker(bind=self.engine)()
+        return self.session
+    
+    def __exit__(self,exc_type, exc_value, traceback):
+        if exc_type is None:
+            if self.autocommit:
+                self.session.commit()
+        else:
+            self.session.rollback()
+        self.session.close()
+
+
+