Extend taggable-mixin to support different Tag models.
Usage is pretty simple. Tag model is default in Taggable constructor but you
can call it with different model like GHOPTaskType that inherits from Tag model.
Both Taggable and Tag models have been updated and they don't use hardcoded Tag
model anymore and instead use cls of class methods or self.__class__. In case
of Taggable it's self.__tag_model.
#!/usr/bin/python
#
# Copyright 2008 Google Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Convenience functions.
"""
from google.appengine.api import datastore
def transactional(operation):
"""Decorator that wraps a method in a datastore transaction.
The method will be called through datastore.RunInTransaction, making the
operation atomic.
"""
def transactional_operation(*args, **kwargs):
return datastore.RunInTransaction(operation, *args, **kwargs)
return transactional_operation