Argument store added to updateEntityProperties.
This argument determines if an entity should be stored in the data model after its properties are updated.
It may be useful, for example, along with tasks (Task Queue API). One may want to make some modifications to an entity during execution of a task, but the developer is sure that at least one new task, which also wants to modify the entity, will be queued, so he or she can just update the entity without saving the changes to the data model, set the entity in memcache and the following task (which is to be executed very shortly) is to retrive the current entity from the memcache (without any expensive calls to the actual data model).
#!/usr/bin/python2.5
#
# Copyright 2009 the Melange authors.
#
# 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.
"""Helpers functions for updating different kinds of Expando models.
"""
__authors__ = [
'"Lennard de Rijk" <ljvderijk@gmail.com>',
]
from soc.logic.models import base
class Logic(base.Logic):
"""Base logic for Expando entity classes.
"""
def __init__(self, model, base_model=None, scope_logic=None,
name=None, skip_properties=None, id_based=False):
"""Defines the name, key_name and model for this entity.
"""
super(Logic, self).__init__(model=model, base_model=base_model,
scope_logic=scope_logic, name=name,
skip_properties=skip_properties,
id_based=id_based)
def updateEntityProperties(self, entity, entity_properties, silent=False,
store=True):
"""Update existing entity using supplied properties.
Overwrites base because of Expando properties.
Args:
entity: a model entity
entity_properties: keyword arguments that correspond to entity
properties and their values
silent: iff True does not call _onUpdate method
store: iff True updated entity is actually stored in the data model
Returns:
The original entity with any supplied properties changed.
"""
if not entity:
raise NoEntityError
if not entity_properties:
raise InvalidArgumentError
for name, value in entity_properties.iteritems():
# if the property is not to be updated, skip it
if name in self._skip_properties:
continue
if self._updateField(entity, entity_properties, name):
setattr(entity, name, value)
if store:
entity.put()
# call the _onUpdate method
if not silent:
self._onUpdate(entity)
return entity