app/soc/logic/models/mentor.py

   1 #!/usr/bin/python2.5
   2 #
   3 # Copyright 2009 the Melange authors.
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License");
   6 # you may not use this file except in compliance with the License.
   7 # You may obtain a copy of the License at
   8 #
   9 #   http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 # See the License for the specific language governing permissions and
  15 # limitations under the License.
  16
  17 """Mentor (Model) query functions.
  18 """
  19
  20 __authors__ = [
  21   '"Lennard de Rijk" <ljvderijk@gmail.com>',
  22   ]
  23
  24
  25 from google.appengine.ext import db
  26
  27 from soc.logic.models import role
  28 from soc.logic.models import organization as org_logic
  29
  30 import soc.models.mentor
  31 import soc.models.role
  32
  33
  34 DEF_ALREADY_MENTORING_RPOJECT_MSG = "This Mentor is mentoring a Student "\
  35     "Project and can therefore not be resigned. Please assign another Mentor."
  36
  37 DEF_ALREADY_MENTORING_PROPOSAL_MSG = "This Mentor is mentoring a Student "\
  38     "Proposal and can therefore not be resigned. Please assign another Mentor."
  39
  40
  41 class Logic(role.Logic):
  42   """Logic methods for the Mentor model.
  43   """
  44
  45   def __init__(self, model=soc.models.mentor.Mentor,
  46                base_model=soc.models.role.Role, scope_logic=org_logic,
  47                disallow_last_resign=False):
  48     """Defines the name, key_name and model for this entity.
  49     """
  50
  51     super(Logic, self).__init__(model=model, base_model=base_model,
  52                                 scope_logic=scope_logic,
  53                                 disallow_last_resign=disallow_last_resign)
  54
  55   def canResign(self, entity):
  56     """Checks if the Mentor is able to resign.
  57
  58     Checks if there are no Student Proposals or Student Projects that
  59     have this mentor assigned to it.
  60
  61     Args:
  62       entity: a Mentor entity
  63
  64     """
  65
  66     from soc.logic.models.student_project import logic as \
  67         student_project_logic
  68     from soc.logic.models.student_proposal import logic as \
  69         student_proposal_logic
  70
  71     fields = {'mentor': entity}
  72
  73     student_project_entity = student_project_logic.getForFields(fields,
  74                                                                 unique=True)
  75     if student_project_entity:
  76       return DEF_ALREADY_MENTORING_RPOJECT_MSG
  77
  78     student_proposal_entity = student_proposal_logic.getForFields(fields,
  79                                                                   unique=True)
  80
  81     if student_proposal_entity:
  82       return DEF_ALREADY_MENTORING_PROPOSAL_MSG
  83
  84     return super(Logic, self).canResign(entity)
  85
  86   def _updateField(self, entity, entity_properties, name):
  87     """Called when the fields of the mentor are updated
  88
  89       When status is changed to invalid, removes the Mentor from all Student
  90       Proposals possible mentor lists.
  91     """
  92
  93     from soc.logic.models.student_proposal import logic \
  94         as student_proposal_logic
  95
  96     value = entity_properties[name]
  97
  98     if name == 'status' and value != entity.status and value == 'invalid':
  99       fields = {'org': entity.scope}
 100
 101       # TODO make this work for more then 1000 entities
 102       proposals_query = student_proposal_logic.getQueryForFields(fields)
 103
 104       # store all updated proposals
 105       changed = []
 106
 107       for proposal in proposals_query:
 108
 109         if proposal.possible_mentors.count(entity.key()):
 110           # remove from list and add to changed
 111           proposal.possible_mentors.remove(entity.key())
 112           changed.append(proposal)
 113
 114       # store all changed proposals
 115       db.put(changed)
 116
 117     return super(Logic, self)._updateField(entity, entity_properties, name)
 118
 119
 120 logic = Logic()