Remove SubfieldBase metaclass

common/djangoapps/student/models.py

@@ -13,6 +13,7 @@ file and check it in at the same time as your model changes. To do that,
 import hashlib
 import json
 import logging
+import six
 import uuid
 from collections import OrderedDict, defaultdict, namedtuple
 from datetime import datetime, timedelta
@@ -1529,7 +1530,7 @@ class CourseEnrollment(models.Model):
 
         if not status_hash:
             enrollments = cls.enrollments_for_user(user).values_list('course_id', 'mode')
-            enrollments = [(e[0].lower(), e[1].lower()) for e in enrollments]
+            enrollments = [(six.text_type(e[0]).lower(), e[1].lower()) for e in enrollments]
             enrollments = sorted(enrollments, key=lambda e: e[0])
             hash_elements = [user.username]
             hash_elements += ['{course_id}={mode}'.format(course_id=e[0], mode=e[1]) for e in enrollments]

common/djangoapps/util/models.py

@@ -7,6 +7,8 @@ from config_models.models import ConfigurationModel
 from django.db import models
 from django.utils.text import compress_string
 
+from openedx.core.djangoapps.util.model_utils import CreatorMixin
+
 logger = logging.getLogger(__name__)  # pylint: disable=invalid-name
 
 
@@ -40,12 +42,10 @@ def decompress_string(value):
     return ret
 
 
-class CompressedTextField(models.TextField):
+class CompressedTextField(CreatorMixin, models.TextField):
     """ TextField that transparently compresses data when saving to the database, and decompresses the data
     when retrieving it from the database. """
 
-    __metaclass__ = models.SubfieldBase
-
     def get_prep_value(self, value):
         """ Compress the text data. """
         if value is not None:

lms/djangoapps/class_dashboard/dashboard_data.py

@@ -45,7 +45,7 @@ def get_problem_grade_distribution(course_id):
 
     # Loop through resultset building data for each problem
     for row in db_query:
-        curr_problem = UsageKey.from_string(row['module_state_key']).map_into_course(course_id)
+        curr_problem = row['module_state_key'].map_into_course(course_id)
 
         # Build set of grade distributions for each problem that has student responses
         if curr_problem in prob_grade_distrib:
@@ -85,7 +85,7 @@ def get_sequential_open_distrib(course_id):
     # Build set of "opened" data for each subsection that has "opened" data
     sequential_open_distrib = {}
     for row in db_query:
-        row_loc = UsageKey.from_string(row['module_state_key']).map_into_course(course_id)
+        row_loc = row['module_state_key'].map_into_course(course_id)
         sequential_open_distrib[row_loc] = row['count_sequential']
 
     return sequential_open_distrib
@@ -122,7 +122,7 @@ def get_problem_set_grade_distrib(course_id, problem_set):
 
     # Loop through resultset building data for each problem
     for row in db_query:
-        row_loc = UsageKey.from_string(row['module_state_key']).map_into_course(course_id)
+        row_loc = row['module_state_key'].map_into_course(course_id)
         if row_loc not in prob_grade_distrib:
             prob_grade_distrib[row_loc] = {
                 'max_grade': 0,

lms/djangoapps/courseware/model_data.py

@@ -960,7 +960,7 @@ class ScoresClient(object):
         # attached to them (since old mongo identifiers don't include runs).
         # So we have to add that info back in before we put it into our lookup.
         self._locations_to_scores.update({
-            UsageKey.from_string(location).map_into_course(self.course_key): self.Score(correct, total, created)
+            location.map_into_course(self.course_key): self.Score(correct, total, created)
             for location, correct, total, created
             in scores_qset.values_list('module_state_key', 'grade', 'max_grade', 'created')
         })

lms/djangoapps/instructor_analytics/basic.py

@@ -199,6 +199,7 @@ def issued_certificates(course_key, features):
     # Report run date
     for data in generated_certificates:
         data['report_run_date'] = report_run_date
+        data['course_id'] = str(data['course_id'])
 
     return generated_certificates
 

lms/djangoapps/teams/views.py

@@ -1055,7 +1055,7 @@ class MembershipListView(ExpandableFieldViewMixin, GenericAPIView):
                     CourseAccessRole.objects.filter(user=request.user, role='staff').values_list('course_id', flat=True)
                 )
                 accessible_course_ids = [item for sublist in (enrolled_courses, staff_courses) for item in sublist]
-                if requested_course_id is not None and requested_course_id not in accessible_course_ids:
+                if requested_course_id is not None and requested_course_key not in accessible_course_ids:
                     return Response(status=status.HTTP_400_BAD_REQUEST)
 
         if not specified_username_or_team:
@@ -1068,7 +1068,7 @@ class MembershipListView(ExpandableFieldViewMixin, GenericAPIView):
         if requested_course_key is not None:
             course_keys = [requested_course_key]
         elif accessible_course_ids is not None:
-            course_keys = [CourseKey.from_string(course_string) for course_string in accessible_course_ids]
+            course_keys = accessible_course_ids
 
         queryset = CourseTeamMembership.get_memberships(username, course_keys, team_id)
         page = self.paginate_queryset(queryset)

openedx/core/djangoapps/content/course_overviews/models.py

@@ -551,10 +551,7 @@ class CourseOverview(TimeStampedModel):
         """
         Returns all course keys from course overviews.
         """
-        return [
-            CourseKey.from_string(course_overview['id'])
-            for course_overview in CourseOverview.objects.values('id')
-        ]
+        return CourseOverview.objects.values_list('id', flat=True)
 
     def is_discussion_tab_enabled(self):
         """

openedx/core/djangoapps/util/model_utils.py

@@ -0,0 +1,27 @@
+class Creator(object):
+    """
+    A placeholder class that provides a way to set the attribute on the model.
+    """
+    def __init__(self, field):
+        self.field = field
+
+    def __get__(self, obj, type=None):
+        if obj is None:
+            return self
+        return obj.__dict__[self.field.name]
+
+    def __set__(self, obj, value):
+        obj.__dict__[self.field.name] = self.field.to_python(value)
+
+
+class CreatorMixin(object):
+    """
+    Mixin class to provide SubfieldBase functionality to django fields.
+    See: https://docs.djangoproject.com/en/1.11/releases/1.8/#subfieldbase
+    """
+    def contribute_to_class(self, cls, name, *args, **kwargs):
+        super(CreatorMixin, self).contribute_to_class(cls, name, *args, **kwargs)
+        setattr(cls, name, Creator(self))
+
+    def from_db_value(self, value, expression, connection, context):
+        return self.to_python(value)

openedx/core/djangoapps/xmodule_django/models.py

@@ -7,7 +7,7 @@ import warnings
 from django.core.exceptions import ValidationError
 from django.db import models
 from opaque_keys.edx.keys import BlockTypeKey, CourseKey, UsageKey
-
+from openedx.core.djangoapps.util.model_utils import CreatorMixin
 from xmodule.modulestore.django import modulestore
 
 log = logging.getLogger(__name__)
@@ -68,7 +68,7 @@ def _strip_value(value, lookup='exact'):
     return stripped_value
 
 
-class OpaqueKeyField(models.CharField):
+class OpaqueKeyField(CreatorMixin, models.CharField):
     """
     A django field for storing OpaqueKeys.
 
@@ -81,8 +81,6 @@ class OpaqueKeyField(models.CharField):
     """
     description = "An OpaqueKey object, saved to the DB in the form of a string."
 
-    __metaclass__ = models.SubfieldBase
-
     Empty = object()
     KEY_CLASS = None