# HG changeset patch
# User Madhusudan.C.S <madhusudancs@gmai.com>
# Date 1253100953 -7200
# Node ID 74d4875b49227ca439e3b3ea111c3b6f1dae49f9
# Parent  04851beb824e036746cf0f1a2577c9125f690a99
Added updater to update the existing Student models with the school_type entry.

Reviewed by: Lennard de Rijk

diff -r 04851beb824e -r 74d4875b4922 app/soc/tasks/updates/student_school_type.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/app/soc/tasks/updates/student_school_type.py	Wed Sep 16 13:35:53 2009 +0200
@@ -0,0 +1,111 @@
+#!/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.
+
+"""Appengine Task to convert the Student datastore model to contain
+school_type.
+"""
+
+__authors__ = [
+    '"Madhusudan.C.S" <madhusudancs@gmail.com>',
+    '"Lennard de Rijk" <ljvderijk@gmail.com>',
+  ]
+
+
+from google.appengine.api.labs import taskqueue
+from google.appengine.ext import db
+
+from django.http import HttpResponse
+
+from soc.views.helper import responses
+
+
+# batch size to use when going through Student entities.
+DEF_BATCH_SIZE = 25
+
+
+def startSchoolTypeUpdate(request, task_url):
+  """Spawns a task for initiating the Student model conversion to include
+  school type.
+
+  Args:
+    request: Django Request object
+    task_url: The URL used to run this update task
+
+  Returns:
+    True iff the new task is successfully added to the Task Queue API
+  """
+
+  new_task = taskqueue.Task(url=task_url)
+  new_task.add()
+
+  return True
+
+
+def runSchoolTypeUpdate(request, *args, **kwargs):
+  """Appengine Task that adds school_type as University for existing
+  Student entities in batches.
+
+  Addition of required school_type property to Student model 
+  requires addition of corresponding value to all the existing 
+  Student entities in the datastore. Since this property is introduced
+  during GSoC 2009 all students should be University students.
+  This task sets the school_type value to "University" to
+  all the existing entities.
+
+  Args:
+    request: Django Request object
+  """
+
+  from soc.logic.models.student import logic as student_logic
+  from soc.models.student import Student
+
+  fields = {}
+
+  post_dict = request.POST
+
+  start_key = post_dict.get('start_key')
+
+  if start_key:
+    # retrieve the last student entity that was converted
+    start = student_logic.getFromKeyName(start_key)
+
+    if not start:
+      # invalid starting student key specified, log and return OK
+      return error_handler.logErrorAndReturnOK(
+          'Invalid Student Key specified: %s' %(start_key))
+
+    fields['__key__ >'] = start.key()
+
+  # get the first batch_size number of StudentProjects
+  entities = student_logic.getForFields(fields, limit=DEF_BATCH_SIZE)
+
+  for entity in entities:
+    entity.school_type = 'University'
+
+  db.put(entities)
+
+  if len(entities) == DEF_BATCH_SIZE:
+    # spawn new task starting from the last
+    new_start = entities[DEF_BATCH_SIZE-1].key().id_or_name()
+
+    # pass along these params as POST to the new task
+    task_params = {'start_key': new_start}
+
+    new_task = taskqueue.Task(params=task_params, url=request['PATH_INFO'])
+    new_task.add()
+
+  # task completed, return OK
+  return HttpResponse('OK')