#!/usr/bin/python2.5

#

# Copyright 2008 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.

"""Presence (Model) query functions.

"""

__authors__ = [

  '"Sverre Rabbelier" <sverre@rabbelier.nl>',

  '"Lennard de Rijk" <ljvderijk@gmail.com>'

  ]

from google.appengine.ext import db

from soc.logic.models import base

from soc.logic.models import linkable as linkable_logic

import soc.models.presence

class Logic(base.Logic):

  """Logic methods for the Presence model.

  """

  def __init__(self, model=soc.models.presence.Presence,

               base_model=None, scope_logic=linkable_logic):

    """Defines the name, key_name and model for this entity.

    """

    super(Logic, self).__init__(model, base_model=base_model,

                                scope_logic=scope_logic)

  def getToS(self, entity):

    """Returns the ToS Document of the Presence entity, or None if no ToS.

    Args:

      entity:  Presence (or one of its sub-classes) entity that may or may

        not have a ToS Document attached

    """

    if not entity:

      return None

    try:

      tos_doc = entity.tos

    except db.Error:

      return None

    return tos_doc

logic = Logic()