Merge pull request #651 from edx/ormsbee/enrollment_modes

Add mode and is_active to CourseEnrollment, shift enrollment logic to model

CHANGELOG.rst

@@ -11,6 +11,15 @@ LMS: Enable beta instructor dashboard. The beta dashboard is a rearchitecture
 of the existing instructor dashboard and is available by clicking a link at
 the top right of the existing dashboard.
 
+Common: CourseEnrollment has new fields `is_active` and `mode`. The mode will be
+used to differentiate different kinds of enrollments (currently, all enrollments
+are honor certificate enrollments). The `is_active` flag will be used to
+deactivate enrollments without deleting them, so that we know what course you
+*were* enrolled in. Because of the latter change, enrollment and unenrollment
+logic has been consolidated into the model -- you should use new class methods
+to `enroll()`, `unenroll()`, and to check `is_enrolled()`, instead of creating
+CourseEnrollment objects or querying them directly.
+
 Studio: Email will be sent to admin address when a user requests course creator
 privileges for Studio (edge only).
 

cms/djangoapps/contentstore/tests/test_contentstore.py

@@ -49,7 +49,7 @@ import datetime
 from pytz import UTC
 from uuid import uuid4
 from pymongo import MongoClient
-from student.views import is_enrolled_in_course
+from student.models import CourseEnrollment
 
 TEST_DATA_CONTENTSTORE = copy.deepcopy(settings.CONTENTSTORE)
 TEST_DATA_CONTENTSTORE['OPTIONS']['db'] = 'test_xcontent_%s' % uuid4().hex
@@ -1168,7 +1168,7 @@ class ContentStoreTest(ModuleStoreTestCase):
         self.assertNotIn('ErrMsg', data)
         self.assertEqual(data['id'], 'i4x://MITx/{0}/course/2013_Spring'.format(test_course_data['number']))
         # Verify that the creator is now registered in the course.
-        self.assertTrue(is_enrolled_in_course(self.user, self._get_course_id(test_course_data)))
+        self.assertTrue(CourseEnrollment.is_enrolled(self.user, self._get_course_id(test_course_data)))
         return test_course_data
 
     def test_create_course_check_forum_seeding(self):
@@ -1190,14 +1190,14 @@ class ContentStoreTest(ModuleStoreTestCase):
         Checks that the course did not get created
         """
         course_id = self._get_course_id(self.course_data)
-        initially_enrolled = is_enrolled_in_course(self.user, course_id)
+        initially_enrolled = CourseEnrollment.is_enrolled(self.user, course_id)
         resp = self.client.post(reverse('create_new_course'), self.course_data)
         self.assertEqual(resp.status_code, 200)
         data = parse_json(resp)
         self.assertEqual(data['ErrMsg'], error_message)
         # One test case involves trying to create the same course twice. Hence for that course,
         # the user will be enrolled. In the other cases, initially_enrolled will be False.
-        self.assertEqual(initially_enrolled, is_enrolled_in_course(self.user, course_id))
+        self.assertEqual(initially_enrolled, CourseEnrollment.is_enrolled(self.user, course_id))
 
     def test_create_course_duplicate_number(self):
         """Test new course creation - error path"""

cms/djangoapps/contentstore/tests/test_users.py

@@ -6,7 +6,7 @@ from .utils import CourseTestCase
 from django.contrib.auth.models import User, Group
 from django.core.urlresolvers import reverse
 from auth.authz import get_course_groupname_for_role
-from student.views import is_enrolled_in_course
+from student.models import CourseEnrollment
 
 
 class UsersTestCase(CourseTestCase):
@@ -372,13 +372,13 @@ class UsersTestCase(CourseTestCase):
     def assert_not_enrolled(self):
         """ Asserts that self.ext_user is not enrolled in self.course. """
         self.assertFalse(
-            is_enrolled_in_course(self.ext_user, self.course.location.course_id),
+            CourseEnrollment.is_enrolled(self.ext_user, self.course.location.course_id),
             'Did not expect ext_user to be enrolled in course'
         )
 
     def assert_enrolled(self):
         """ Asserts that self.ext_user is enrolled in self.course. """
         self.assertTrue(
-            is_enrolled_in_course(self.ext_user, self.course.location.course_id),
+            CourseEnrollment.is_enrolled(self.ext_user, self.course.location.course_id),
             'User ext_user should have been enrolled in the course'
         )

cms/djangoapps/contentstore/views/course.py

@@ -44,7 +44,7 @@ from .component import (
 
 from django_comment_common.utils import seed_permissions_roles
 
-from student.views import enroll_in_course
+from student.models import CourseEnrollment
 
 from xmodule.html_module import AboutDescriptor
 __all__ = ['course_index', 'create_new_course', 'course_info',
@@ -165,7 +165,7 @@ def create_new_course(request):
     seed_permissions_roles(new_course.location.course_id)
 
     # auto-enroll the course creator in the course so that "View Live" will work.
-    enroll_in_course(request.user, new_course.location.course_id)
+    CourseEnrollment.enroll(request.user, new_course.location.course_id)
 
     return JsonResponse({'id': new_course.location.url()})
 

cms/djangoapps/contentstore/views/user.py

@@ -24,7 +24,7 @@ from course_creators.views import (
 
 from .access import has_access
 
-from student.views import enroll_in_course
+from student.models import CourseEnrollment
 
 
 @login_required
@@ -208,7 +208,7 @@ def course_team_user(request, org, course, name, email):
         user.groups.add(groups["instructor"])
         user.save()
         # auto-enroll the course creator in the course so that "View Live" will work.
-        enroll_in_course(user, location.course_id)
+        CourseEnrollment.enroll(user, location.course_id)
     elif role == "staff":
         # if we're trying to downgrade a user from "instructor" to "staff",
         # make sure we have at least one other instructor in the course team.
@@ -223,7 +223,7 @@ def course_team_user(request, org, course, name, email):
         user.groups.add(groups["staff"])
         user.save()
         # auto-enroll the course creator in the course so that "View Live" will work.
-        enroll_in_course(user, location.course_id)
+        CourseEnrollment.enroll(user, location.course_id)
 
     return JsonResponse()
 

common/djangoapps/django_comment_common/models.py

@@ -19,6 +19,20 @@ FORUM_ROLE_STUDENT = 'Student'
 
 @receiver(post_save, sender=CourseEnrollment)
 def assign_default_role(sender, instance, **kwargs):
+    # The code below would remove all forum Roles from a user when they unenroll
+    # from a course. Concerns were raised that it should apply only to students,
+    # or that even the history of student roles is important for research
+    # purposes. Since this was new functionality being added in this release,
+    # I'm just going to comment it out for now and let the forums team deal with
+    # implementing the right behavior.
+    #
+    # # We've unenrolled the student, so remove all roles for this course
+    # if not instance.is_active:
+    #     course_roles = list(Role.objects.filter(course_id=instance.course_id))
+    #     instance.user.roles.remove(*course_roles)
+    #     return
+
+    # We've enrolled the student, so make sure they have a default role
     if instance.user.is_staff:
         role = Role.objects.get_or_create(course_id=instance.course_id, name="Moderator")[0]
     else:

common/djangoapps/django_comment_common/tests.py

+from django.test import TestCase
+
+from django_comment_common.models import Role
+from student.models import CourseEnrollment, User
+
+class RoleAssignmentTest(TestCase):
+    """
+    Basic checks to make sure our Roles get assigned and unassigned as students
+    are enrolled and unenrolled from a course.
+    """
+
+    def setUp(self):
+        self.staff_user = User.objects.create_user(
+            "patty",
+            "patty@fake.edx.org",
+        )
+        self.staff_user.is_staff = True
+
+        self.student_user = User.objects.create_user(
+            "hacky",
+            "hacky@fake.edx.org"
+        )
+        self.course_id = "edX/Fake101/2012"
+        CourseEnrollment.enroll(self.staff_user, self.course_id)
+        CourseEnrollment.enroll(self.student_user, self.course_id)
+
+    def test_enrollment_auto_role_creation(self):
+        moderator_role = Role.objects.get(
+            course_id=self.course_id,
+            name="Moderator"
+        )
+        student_role = Role.objects.get(
+            course_id=self.course_id,
+            name="Student"
+        )
+        self.assertIn(moderator_role, self.staff_user.roles.all())
+
+        self.assertIn(student_role, self.student_user.roles.all())
+        self.assertNotIn(moderator_role, self.student_user.roles.all())
+
+    # The following was written on the assumption that unenrolling from a course
+    # should remove all forum Roles for that student for that course. This is
+    # not necessarily the case -- please see comments at the top of 
+    # django_comment_client.models.assign_default_role(). Leaving it for the
+    # forums team to sort out.
+    #
+    # def test_unenrollment_auto_role_removal(self):
+    #     another_student = User.objects.create_user("sol", "sol@fake.edx.org")
+    #     CourseEnrollment.enroll(another_student, self.course_id)
+    #
+    #     CourseEnrollment.unenroll(self.student_user, self.course_id)
+    #     # Make sure we didn't delete the actual Role
+    #     student_role = Role.objects.get(
+    #         course_id=self.course_id,
+    #         name="Student"
+    #     )
+    #     self.assertNotIn(student_role, self.student_user.roles.all())
+    #     self.assertIn(student_role, another_student.roles.all())

common/djangoapps/external_auth/tests/test_shib.py

@@ -431,12 +431,12 @@ class ShibSPTest(ModuleStoreTestCase):
                 # If course is not limited or student has correct shib extauth then enrollment should be allowed
                 if course is open_enroll_course or student is shib_student:
                     self.assertEqual(response.status_code, 200)
-                    self.assertEqual(CourseEnrollment.objects.filter(user=student, course_id=course.id).count(), 1)
+                    self.assertTrue(CourseEnrollment.is_enrolled(student, course.id))
                     # Clean up
-                    CourseEnrollment.objects.filter(user=student, course_id=course.id).delete()
+                    CourseEnrollment.unenroll(student, course.id)
                 else:
                     self.assertEqual(response.status_code, 400)
-                    self.assertEqual(CourseEnrollment.objects.filter(user=student, course_id=course.id).count(), 0)
+                    self.assertFalse(CourseEnrollment.is_enrolled(student, course.id))
 
     @unittest.skipUnless(settings.MITX_FEATURES.get('AUTH_USE_SHIB'), True)
     def test_shib_login_enrollment(self):
@@ -462,7 +462,7 @@ class ShibSPTest(ModuleStoreTestCase):
 
         # use django test client for sessions and url processing
         # no enrollment before trying
-        self.assertEqual(CourseEnrollment.objects.filter(user=student, course_id=course.id).count(), 0)
+        self.assertFalse(CourseEnrollment.is_enrolled(student, course.id))
         self.client.logout()
         request_kwargs = {'path': '/shib-login/',
                           'data': {'enrollment_action': 'enroll', 'course_id': course.id},
@@ -474,4 +474,4 @@ class ShibSPTest(ModuleStoreTestCase):
         self.assertEqual(response.status_code, 302)
         self.assertEqual(response['location'], 'http://testserver/')
         # now there is enrollment
-        self.assertEqual(CourseEnrollment.objects.filter(user=student, course_id=course.id).count(), 1)
+        self.assertTrue(CourseEnrollment.is_enrolled(student, course.id))

common/djangoapps/student/management/commands/create_random_users.py

@@ -12,7 +12,7 @@ def create(n, course_id):
     for i in range(n):
         (user, user_profile, _) = _do_create_account(get_random_post_override())
         if course_id is not None:
-            CourseEnrollment.objects.create(user=user, course_id=course_id)
+            CourseEnrollment.enroll(user, course_id)
 
 
 class Command(BaseCommand):

common/djangoapps/student/models.py

@@ -11,11 +11,11 @@ file and check it in at the same time as your model changes. To do that,
 3. Add the migration file created in edx-platform/common/djangoapps/student/migrations/
 """
 from datetime import datetime
+from random import randint
 import hashlib
 import json
 import logging
 import uuid
-from random import randint
 
 
 from django.conf import settings
@@ -645,16 +645,223 @@ class PendingEmailChange(models.Model):
 
 
 class CourseEnrollment(models.Model):
+    """
+    Represents a Student's Enrollment record for a single Course. You should
+    generally not manipulate CourseEnrollment objects directly, but use the
+    classmethods provided to enroll, unenroll, or check on the enrollment status
+    of a given student.
+
+    We're starting to consolidate course enrollment logic in this class, but
+    more should be brought in (such as checking against CourseEnrollmentAllowed,
+    checking course dates, user permissions, etc.) This logic is currently
+    scattered across our views.
+    """
     user = models.ForeignKey(User)
     course_id = models.CharField(max_length=255, db_index=True)
-
     created = models.DateTimeField(auto_now_add=True, null=True, db_index=True)
 
+    # If is_active is False, then the student is not considered to be enrolled
+    # in the course (is_enrolled() will return False)
+    is_active = models.BooleanField(default=True)
+
+    # Represents the modes that are possible. We'll update this later with a
+    # list of possible values.
+    mode = models.CharField(default="honor", max_length=100)
+
+
     class Meta:
         unique_together = (('user', 'course_id'),)
+        ordering = ('user', 'course_id')
 
     def __unicode__(self):
-        return "[CourseEnrollment] %s: %s (%s)" % (self.user, self.course_id, self.created)
+        return (
+            "[CourseEnrollment] {}: {} ({}); active: ({})"
+        ).format(self.user, self.course_id, self.created, self.is_active)
+
+    @classmethod
+    def create_enrollment(cls, user, course_id, mode="honor", is_active=False):
+        """
+        Create an enrollment for a user in a class. By default *this enrollment
+        is not active*. This is useful for when an enrollment needs to go
+        through some sort of approval process before being activated. If you
+        don't need this functionality, just call `enroll()` instead.
+
+        Returns a CoursewareEnrollment object.
+
+        `user` is a Django User object. If it hasn't been saved yet (no `.id`
+               attribute), this method will automatically save it before
+               adding an enrollment for it.
+
+        `course_id` is our usual course_id string (e.g. "edX/Test101/2013_Fall)
+
+        `mode` is a string specifying what kind of enrollment this is. The
+               default is "honor", meaning honor certificate. Future options
+               may include "audit", "verified_id", etc. Please don't use it
+               until we have these mapped out.
+
+        `is_active` is a boolean. If the CourseEnrollment object has
+                    `is_active=False`, then calling
+                    `CourseEnrollment.is_enrolled()` for that user/course_id
+                    will return False.
+
+        It is expected that this method is called from a method which has already
+        verified the user authentication and access.
+        """
+        # If we're passing in a newly constructed (i.e. not yet persisted) User,
+        # save it to the database so that it can have an ID that we can throw
+        # into our CourseEnrollment object. Otherwise, we'll get an
+        # IntegrityError for having a null user_id.
+        if user.id is None:
+            user.save()
+
+        enrollment, _ = CourseEnrollment.objects.get_or_create(
+            user=user,
+            course_id=course_id,
+        )
+        # In case we're reactivating a deactivated enrollment, or changing the
+        # enrollment mode.
+        if enrollment.mode != mode or enrollment.is_active != is_active:
+            enrollment.mode = mode
+            enrollment.is_active = is_active
+            enrollment.save()
+
+        return enrollment
+
+    @classmethod
+    def enroll(cls, user, course_id, mode="honor"):
+        """
+        Enroll a user in a course. This saves immediately.
+
+        Returns a CoursewareEnrollment object.
+
+        `user` is a Django User object. If it hasn't been saved yet (no `.id`
+               attribute), this method will automatically save it before
+               adding an enrollment for it.
+
+        `course_id` is our usual course_id string (e.g. "edX/Test101/2013_Fall)
+
+        `mode` is a string specifying what kind of enrollment this is. The
+               default is "honor", meaning honor certificate. Future options
+               may include "audit", "verified_id", etc. Please don't use it
+               until we have these mapped out.
+
+        It is expected that this method is called from a method which has already
+        verified the user authentication and access.
+        """
+        return cls.create_enrollment(user, course_id, mode, is_active=True)
+
+    @classmethod
+    def enroll_by_email(cls, email, course_id, mode="honor", ignore_errors=True):
+        """
+        Enroll a user in a course given their email. This saves immediately.
+
+        Note that  enrolling by email is generally done in big batches and the
+        error rate is high. For that reason, we supress User lookup errors by
+        default.
+
+        Returns a CoursewareEnrollment object. If the User does not exist and
+        `ignore_errors` is set to `True`, it will return None.
+
+        `email` Email address of the User to add to enroll in the course.
+
+        `course_id` is our usual course_id string (e.g. "edX/Test101/2013_Fall)
+
+        `mode` is a string specifying what kind of enrollment this is. The
+               default is "honor", meaning honor certificate. Future options
+               may include "audit", "verified_id", etc. Please don't use it
+               until we have these mapped out.
+
+        `ignore_errors` is a boolean indicating whether we should suppress
+                        `User.DoesNotExist` errors (returning None) or let it
+                        bubble up.
+
+        It is expected that this method is called from a method which has already
+        verified the user authentication and access.
+        """
+        try:
+            user = User.objects.get(email=email)
+            return cls.enroll(user, course_id, mode)
+        except User.DoesNotExist:
+            err_msg = u"Tried to enroll email {} into course {}, but user not found"
+            log.error(err_msg.format(email, course_id))
+            if ignore_errors:
+                return None
+            raise
+
+    @classmethod
+    def unenroll(cls, user, course_id):
+        """
+        Remove the user from a given course. If the relevant `CourseEnrollment`
+        object doesn't exist, we log an error but don't throw an exception.
+
+        `user` is a Django User object. If it hasn't been saved yet (no `.id`
+               attribute), this method will automatically save it before
+               adding an enrollment for it.
+
+        `course_id` is our usual course_id string (e.g. "edX/Test101/2013_Fall)
+        """
+        try:
+            record = CourseEnrollment.objects.get(user=user, course_id=course_id)
+            record.is_active = False
+            record.save()
+        except cls.DoesNotExist:
+            log.error("Tried to unenroll student {} from {} but they were not enrolled")
+
+    @classmethod
+    def unenroll_by_email(cls, email, course_id):
+        """
+        Unenroll a user from a course given their email. This saves immediately.
+        User lookup errors are logged but will not throw an exception.
+
+        `email` Email address of the User to unenroll from the course.
+
+        `course_id` is our usual course_id string (e.g. "edX/Test101/2013_Fall)
+        """
+        try:
+            user = User.objects.get(email=email)
+            return cls.unenroll(user, course_id)
+        except User.DoesNotExist:
+            err_msg = u"Tried to unenroll email {} from course {}, but user not found"
+            log.error(err_msg.format(email, course_id))
+
+    @classmethod
+    def is_enrolled(cls, user, course_id):
+        """
+        Remove the user from a given course. If the relevant `CourseEnrollment`
+        object doesn't exist, we log an error but don't throw an exception.
+
+        Returns True if the user is enrolled in the course (the entry must exist
+        and it must have `is_active=True`). Otherwise, returns False.
+
+        `user` is a Django User object. If it hasn't been saved yet (no `.id`
+               attribute), this method will automatically save it before
+               adding an enrollment for it.
+
+        `course_id` is our usual course_id string (e.g. "edX/Test101/2013_Fall)
+        """
+        try:
+            record = CourseEnrollment.objects.get(user=user, course_id=course_id)
+            return record.is_active
+        except cls.DoesNotExist:
+            return False
+
+    @classmethod
+    def enrollments_for_user(cls, user):
+        return CourseEnrollment.objects.filter(user=user, is_active=1)
+
+    def activate(self):
+        """Makes this `CourseEnrollment` record active. Saves immediately."""
+        if not self.is_active:
+            self.is_active = True
+            self.save()
+
+    def deactivate(self):
+        """Makes this `CourseEnrollment` record inactive. Saves immediately. An
+        inactive record means that the student is not enrolled in this course.
+        """
+        if self.is_active:
+            self.is_active = False
+            self.save()
 
 
 class CourseEnrollmentAllowed(models.Model):

common/djangoapps/student/tests/tests.py

@@ -21,9 +21,8 @@ from django.utils.http import int_to_base36
 from mock import Mock, patch
 from textwrap import dedent
 
-from student.models import unique_id_for_user
+from student.models import unique_id_for_user, CourseEnrollment
 from student.views import process_survey_link, _cert_info, password_reset, password_reset_confirm_wrapper
-from student.views import enroll_in_course, is_enrolled_in_course
 from student.tests.factories import UserFactory
 from student.tests.test_email import mock_render_to_string
 COURSE_1 = 'edX/toy/2012_Fall'
@@ -209,12 +208,127 @@ class CourseEndingTest(TestCase):
 
 
 class EnrollInCourseTest(TestCase):
-    """ Tests the helper method for enrolling a user in a class """
+    """Tests enrolling and unenrolling in courses."""
 
-    def test_enroll_in_course(self):
+    def test_enrollment(self):
         user = User.objects.create_user("joe", "joe@joe.com", "password")
-        user.save()
-        course_id = "course_id"
-        self.assertFalse(is_enrolled_in_course(user, course_id))
-        enroll_in_course(user, course_id)
-        self.assertTrue(is_enrolled_in_course(user, course_id))
+        course_id = "edX/Test101/2013"
+
+        # Test basic enrollment
+        self.assertFalse(CourseEnrollment.is_enrolled(user, course_id))
+        CourseEnrollment.enroll(user, course_id)
+        self.assertTrue(CourseEnrollment.is_enrolled(user, course_id))
+
+        # Enrolling them again should be harmless
+        CourseEnrollment.enroll(user, course_id)
+        self.assertTrue(CourseEnrollment.is_enrolled(user, course_id))
+
+        # Now unenroll the user
+        CourseEnrollment.unenroll(user, course_id)
+        self.assertFalse(CourseEnrollment.is_enrolled(user, course_id))
+
+        # Unenrolling them again should also be harmless
+        CourseEnrollment.unenroll(user, course_id)
+        self.assertFalse(CourseEnrollment.is_enrolled(user, course_id))
+
+        # The enrollment record should still exist, just be inactive
+        enrollment_record = CourseEnrollment.objects.get(
+            user=user,
+            course_id=course_id
+        )
+        self.assertFalse(enrollment_record.is_active)
+
+    def test_enrollment_non_existent_user(self):
+        # Testing enrollment of newly unsaved user (i.e. no database entry)
+        user = User(username="rusty", email="rusty@fake.edx.org")
+        course_id = "edX/Test101/2013"
+
+        self.assertFalse(CourseEnrollment.is_enrolled(user, course_id))
+
+        # Unenroll does nothing
+        CourseEnrollment.unenroll(user, course_id)
+
+        # Implicit save() happens on new User object when enrolling, so this
+        # should still work
+        CourseEnrollment.enroll(user, course_id)
+        self.assertTrue(CourseEnrollment.is_enrolled(user, course_id))
+
+    def test_enrollment_by_email(self):
+        user = User.objects.create(username="jack", email="jack@fake.edx.org")
+        course_id = "edX/Test101/2013"
+
+        CourseEnrollment.enroll_by_email("jack@fake.edx.org", course_id)
+        self.assertTrue(CourseEnrollment.is_enrolled(user, course_id))
+
+        # This won't throw an exception, even though the user is not found
+        self.assertIsNone(
+            CourseEnrollment.enroll_by_email("not_jack@fake.edx.org", course_id)
+        )
+
+        self.assertRaises(
+            User.DoesNotExist,
+            CourseEnrollment.enroll_by_email,
+            "not_jack@fake.edx.org",
+            course_id,
+            ignore_errors=False
+        )
+
+        # Now unenroll them by email
+        CourseEnrollment.unenroll_by_email("jack@fake.edx.org", course_id)
+        self.assertFalse(CourseEnrollment.is_enrolled(user, course_id))
+
+        # Harmless second unenroll
+        CourseEnrollment.unenroll_by_email("jack@fake.edx.org", course_id)
+        self.assertFalse(CourseEnrollment.is_enrolled(user, course_id))
+
+        # Unenroll on non-existent user shouldn't throw an error
+        CourseEnrollment.unenroll_by_email("not_jack@fake.edx.org", course_id)
+
+    def test_enrollment_multiple_classes(self):
+        user = User(username="rusty", email="rusty@fake.edx.org")
+        course_id1 = "edX/Test101/2013"
+        course_id2 = "MITx/6.003z/2012"
+
+        CourseEnrollment.enroll(user, course_id1)
+        CourseEnrollment.enroll(user, course_id2)
+        self.assertTrue(CourseEnrollment.is_enrolled(user, course_id1))
+        self.assertTrue(CourseEnrollment.is_enrolled(user, course_id2))
+
+        CourseEnrollment.unenroll(user, course_id1)
+        self.assertFalse(CourseEnrollment.is_enrolled(user, course_id1))
+        self.assertTrue(CourseEnrollment.is_enrolled(user, course_id2))
+
+        CourseEnrollment.unenroll(user, course_id2)
+        self.assertFalse(CourseEnrollment.is_enrolled(user, course_id1))
+        self.assertFalse(CourseEnrollment.is_enrolled(user, course_id2))
+
+    def test_activation(self):
+        user = User.objects.create(username="jack", email="jack@fake.edx.org")
+        course_id = "edX/Test101/2013"
+        self.assertFalse(CourseEnrollment.is_enrolled(user, course_id))
+
+        # Creating an enrollment doesn't actually enroll a student
+        # (calling CourseEnrollment.enroll() would have)
+        enrollment = CourseEnrollment.create_enrollment(user, course_id)
+        self.assertFalse(CourseEnrollment.is_enrolled(user, course_id))
+
+        # Until you explicitly activate it
+        enrollment.activate()
+        self.assertTrue(CourseEnrollment.is_enrolled(user, course_id))
+
+        # Activating something that's already active does nothing
+        enrollment.activate()
+        self.assertTrue(CourseEnrollment.is_enrolled(user, course_id))
+
+        # Now deactive
+        enrollment.deactivate()
+        self.assertFalse(CourseEnrollment.is_enrolled(user, course_id))
+
+        # Deactivating something that's already inactive does nothing
+        enrollment.deactivate()
+        self.assertFalse(CourseEnrollment.is_enrolled(user, course_id))
+
+        # A deactivated enrollment should be activated if enroll() is called
+        # for that user/course_id combination
+        CourseEnrollment.enroll(user, course_id)
+        self.assertTrue(CourseEnrollment.is_enrolled(user, course_id))

common/djangoapps/student/views.py

@@ -254,13 +254,12 @@ def register_user(request, extra_context=None):
 @ensure_csrf_cookie
 def dashboard(request):
     user = request.user
-    enrollments = CourseEnrollment.objects.filter(user=user)
 
     # Build our courses list for the user, but ignore any courses that no longer
     # exist (because the course IDs have changed). Still, we don't delete those
     # enrollments, because it could have been a data push snafu.
     courses = []
-    for enrollment in enrollments:
+    for enrollment in CourseEnrollment.enrollments_for_user(user):
         try:
             courses.append(course_from_id(enrollment.course_id))
         except ItemNotFoundError:
@@ -377,18 +376,13 @@ def change_enrollment(request):
                                "course:{0}".format(course_num),
                                "run:{0}".format(run)])
 
-        try:
-            enroll_in_course(user, course.id)
-        except IntegrityError:
-            # If we've already created this enrollment in a separate transaction,
-            # then just continue
-            pass
+        CourseEnrollment.enroll(user, course.id)
+
         return HttpResponse()
 
     elif action == "unenroll":
         try:
-            enrollment = CourseEnrollment.objects.get(user=user, course_id=course_id)
-            enrollment.delete()
+            CourseEnrollment.unenroll(user, course_id)
 
             org, course_num, run = course_id.split("/")
             statsd.increment("common.student.unenrollment",
@@ -402,30 +396,10 @@ def change_enrollment(request):
     else:
         return HttpResponseBadRequest(_("Enrollment action is invalid"))
 
-
-def enroll_in_course(user, course_id):
-    """
-    Helper method to enroll a user in a particular class.
-
-    It is expected that this method is called from a method which has already
-    verified the user authentication and access.
-    """
-    CourseEnrollment.objects.get_or_create(user=user, course_id=course_id)
-
-
-def is_enrolled_in_course(user, course_id):
-    """
-    Helper method that returns whether or not the user is enrolled in a particular course.
-    """
-    return CourseEnrollment.objects.filter(user=user, course_id=course_id).count() > 0
-
-
 @ensure_csrf_cookie
 def accounts_login(request, error=""):
-
     return render_to_response('login.html', {'error': error})
 
-
 # Need different levels of logging
 @ensure_csrf_cookie
 def login_user(request, error=""):
@@ -1008,13 +982,21 @@ def activate_account(request, key):
             ceas = CourseEnrollmentAllowed.objects.filter(email=student[0].email)
             for cea in ceas:
                 if cea.auto_enroll:
-                    course_id = cea.course_id
-                    _enrollment, _created = CourseEnrollment.objects.get_or_create(user_id=student[0].id, course_id=course_id)
-
-        resp = render_to_response("registration/activation_complete.html", {'user_logged_in': user_logged_in, 'already_active': already_active})
+                    CourseEnrollment.enroll(student[0], cea.course_id)
+
+        resp = render_to_response(
+            "registration/activation_complete.html",
+            {
+                'user_logged_in': user_logged_in,
+                'already_active': already_active
+            }
+        )
         return resp
     if len(r) == 0:
-        return render_to_response("registration/activation_invalid.html", {'csrf': csrf(request)['csrf_token']})
+        return render_to_response(
+            "registration/activation_invalid.html",
+            {'csrf': csrf(request)['csrf_token']}
+        )
     return HttpResponse(_("Unknown error. Please e-mail us to let us know how it happened."))
 
 

common/djangoapps/terrain/course_helpers.py

@@ -54,7 +54,7 @@ def register_by_course_id(course_id, is_staff=False):
     if is_staff:
         u.is_staff = True
         u.save()
-    CourseEnrollment.objects.get_or_create(user=u, course_id=course_id)
+    CourseEnrollment.enroll(u, course_id)
 
 
 @world.absorb

docs/data/source/internal_data_formats/sql_schema.rst

@@ -347,7 +347,7 @@ There is an important split in demographic data gathered for the students who si
 
 `student_courseenrollment`
 ==========================
-A row in this table represents a student's enrollment for a particular course run. If they decide to unenroll in the course, we delete their entry in this table, but we still leave all their state in `courseware_studentmodule` untouched.
+A row in this table represents a student's enrollment for a particular course run. If they decide to unenroll in the course, we set `is_active` to `False`. We still leave all their state in `courseware_studentmodule` untouched, so they will not lose courseware state if they unenroll and reenroll.
 
 `id`
 ----
@@ -365,6 +365,13 @@ A row in this table represents a student's enrollment for a particular course ru
 ---------
   Datetime of enrollment, UTC.
 
+`is_active`
+-----------
+  Boolean indicating whether this enrollment is active. If an enrollment is not active, a student is not enrolled in that course. This lets us unenroll students without losing a record of what courses they were enrolled in previously. This was introduced in the 2013-08-20 release. Before this release, unenrolling a student simply deleted the row in `student_courseenrollment`.
+
+`mode`
+------
+  String indicating what kind of enrollment this was. The default is "honor" (honor certificate) and all enrollments prior to 2013-08-20 will be of that type. Other types being considered are "audit" and "verified_id".
 
 
 *******************

lms/djangoapps/analytics/basic.py

@@ -25,8 +25,10 @@ def enrolled_students_features(course_id, features):
         {'username': 'username3', 'first_name': 'firstname3'}
     ]
     """
-    students = User.objects.filter(courseenrollment__course_id=course_id)\
-        .order_by('username').select_related('profile')
+    students = User.objects.filter(
+        courseenrollment__course_id=course_id,
+        courseenrollment__is_active=1,
+    ).order_by('username').select_related('profile')
 
     def extract_student(student, features):
         """ convert student to dictionary """

lms/djangoapps/analytics/tests/test_basic.py

@@ -15,7 +15,8 @@ class TestAnalyticsBasic(TestCase):
     def setUp(self):
         self.course_id = 'some/robot/course/id'
         self.users = tuple(UserFactory() for _ in xrange(30))
-        self.ces = tuple(CourseEnrollment.objects.create(course_id=self.course_id, user=user) for user in self.users)
+        self.ces = tuple(CourseEnrollment.enroll(user, self.course_id)
+                         for user in self.users)
 
     def test_enrolled_students_features_username(self):
         self.assertIn('username', AVAILABLE_FEATURES)

lms/djangoapps/analytics/tests/test_distributions.py

@@ -19,10 +19,8 @@ class TestAnalyticsDistributions(TestCase):
             profile__year_of_birth=i + 1930
         ) for i in xrange(30)]
 
-        self.ces = [CourseEnrollment.objects.create(
-            course_id=self.course_id,
-            user=user
-        ) for user in self.users]
+        self.ces = [CourseEnrollment.enroll(user, self.course_id)
+                    for user in self.users]
 
     @raises(ValueError)
     def test_profile_distribution_bad_feature(self):
@@ -68,7 +66,8 @@ class TestAnalyticsDistributionsNoData(TestCase):
 
         self.users += self.nodata_users
 
-        self.ces = tuple(CourseEnrollment.objects.create(course_id=self.course_id, user=user) for user in self.users)
+        self.ces = tuple(CourseEnrollment.enroll(user, self.course_id)
+                         for user in self.users)
 
     def test_profile_distribution_easy_choice_nodata(self):
         feature = 'gender'

lms/djangoapps/courseware/features/common.py

@@ -53,7 +53,7 @@ def i_am_registered_for_the_course(step, course):
 
     # If the user is not already enrolled, enroll the user.
     # TODO: change to factory
-    CourseEnrollment.objects.get_or_create(user=u, course_id=course_id(course))
+    CourseEnrollment.enroll(u, course_id(course))
 
     world.log_in(username='robot', password='test')
 

lms/djangoapps/courseware/features/navigation.py

@@ -149,7 +149,7 @@ def create_user_and_visit_course():
     world.create_user('robot', 'test')
     u = User.objects.get(username='robot')
 
-    CourseEnrollment.objects.get_or_create(user=u, course_id=course_id(world.scenario_dict['COURSE'].number))
+    CourseEnrollment.enroll(u, course_id(world.scenario_dict['COURSE'].number))
 
     world.log_in(username='robot', password='test')
     chapter_name = (TEST_SECTION_NAME + "1").replace(" ", "_")

lms/djangoapps/courseware/tests/test_views.py

@@ -67,9 +67,9 @@ class ViewsTestCase(TestCase):
                                         email='test@mit.edu')
         self.date = datetime.datetime(2013, 1, 22, tzinfo=UTC)
         self.course_id = 'edX/toy/2012_Fall'
-        self.enrollment = CourseEnrollment.objects.get_or_create(user=self.user,
-                                                                 course_id=self.course_id,
-                                                                 created=self.date)[0]
+        self.enrollment = CourseEnrollment.enroll(self.user, self.course_id)
+        self.enrollment.created = self.date
+        self.enrollment.save()
         self.location = ['tag', 'org', 'course', 'category', 'name']
         self._MODULESTORES = {}
         # This is a CourseDescriptor object

lms/djangoapps/courseware/views.py

@@ -568,12 +568,12 @@ def syllabus(request, course_id):
 
 def registered_for_course(course, user):
     """
-    Return CourseEnrollment if user is registered for course, else False
+    Return True if user is registered for course, else False
     """
     if user is None:
         return False
     if user.is_authenticated():
-        return CourseEnrollment.objects.filter(user=user, course_id=course.id).exists()
+        return CourseEnrollment.is_enrolled(user, course.id)
     else:
         return False
 

lms/djangoapps/dashboard/views.py

@@ -47,7 +47,7 @@ def dashboard(request):
     results["scalars"]["Activated Usernames"]=User.objects.filter(is_active=1).count()
     
     # count how many enrollments we have
-    results["scalars"]["Total Enrollments Across All Courses"]=CourseEnrollment.objects.count()
+    results["scalars"]["Total Enrollments Across All Courses"] = CourseEnrollment.objects.filter(is_active=1).count()
 
     # establish a direct connection to the database (for executing raw SQL)
     cursor = connection.cursor()
@@ -56,20 +56,22 @@ def dashboard(request):
     # table queries need not take the form of raw SQL, but do in this case since
     # the MySQL backend for django isn't very friendly with group by or distinct
     table_queries = {}
-    table_queries["course enrollments"]= \
-        "select "+ \
-        "course_id as Course, "+ \
-        "count(user_id) as Students " + \
-        "from student_courseenrollment "+ \
-        "group by course_id "+ \
-        "order by students desc;"
-    table_queries["number of students in each number of classes"]= \
-        "select registrations as 'Registered for __ Classes' , "+ \
-        "count(registrations) as Users "+ \
-        "from (select count(user_id) as registrations "+ \
-               "from student_courseenrollment "+ \
-               "group by user_id) as registrations_per_user "+ \
-        "group by registrations;"
+    table_queries["course enrollments"] = """
+        select
+        course_id as Course,
+        count(user_id) as Students
+        from student_courseenrollment
+        where is_active=1
+        group by course_id
+        order by students desc;"""
+    table_queries["number of students in each number of classes"] = """
+        select registrations as 'Registered for __ Classes' ,
+        count(registrations) as Users
+        from (select count(user_id) as registrations
+               from student_courseenrollment
+               where is_active=1
+               group by user_id) as registrations_per_user
+        group by registrations;"""
 
     # add the result for each of the table_queries to the results object
     for query in table_queries.keys():

lms/djangoapps/django_comment_client/management/commands/assign_roles_for_course.py

@@ -22,7 +22,7 @@ class Command(BaseCommand):
         course_id = args[0]
 
         print "Updated roles for ",
-        for i, enrollment in enumerate(CourseEnrollment.objects.filter(course_id=course_id), start=1):
+        for i, enrollment in enumerate(CourseEnrollment.objects.filter(course_id=course_id, is_active=1), start=1):
             assign_default_role(None, enrollment)
             if i % 1000 == 0:
                 print "{0}...".format(i),

lms/djangoapps/django_comment_client/management/commands/create_roles_for_existing.py

@@ -19,7 +19,7 @@ class Command(BaseCommand):
             raise CommandError("This Command takes no arguments")
 
         print "Updated roles for ",
-        for i, enrollment in enumerate(CourseEnrollment.objects.all(), start=1):
+        for i, enrollment in enumerate(CourseEnrollment.objects.filter(is_active=1), start=1):
             assign_default_role(None, enrollment)
             if i % 1000 == 0:
                 print "{0}...".format(i),

lms/djangoapps/django_comment_client/tests.py

@@ -26,8 +26,8 @@ class PermissionsTestCase(TestCase):
                                              password="123456", email="staff@edx.org")
         self.moderator.is_staff = True
         self.moderator.save()
-        self.student_enrollment = CourseEnrollment.objects.create(user=self.student, course_id=self.course_id)
-        self.moderator_enrollment = CourseEnrollment.objects.create(user=self.moderator, course_id=self.course_id)
+        self.student_enrollment = CourseEnrollment.enroll(self.student, self.course_id)
+        self.moderator_enrollment = CourseEnrollment.enroll(self.moderator, self.course_id)
 
     def tearDown(self):
         self.student_enrollment.delete()

lms/djangoapps/instructor/enrollment.py

@@ -14,7 +14,11 @@ class EmailEnrollmentState(object):
     """ Store the complete enrollment state of an email in a class """
     def __init__(self, course_id, email):
         exists_user = User.objects.filter(email=email).exists()
-        exists_ce = CourseEnrollment.objects.filter(course_id=course_id, user__email=email).exists()
+        if exists_user:
+            user = User.objects.get(email=email)
+            exists_ce = CourseEnrollment.is_enrolled(user, course_id)
+        else:
+            exists_ce = False
         ceas = CourseEnrollmentAllowed.objects.filter(course_id=course_id, email=email).all()
         exists_allowed = len(ceas) > 0
         state_auto_enroll = exists_allowed and ceas[0].auto_enroll
@@ -66,8 +70,7 @@ def enroll_email(course_id, student_email, auto_enroll=False):
     previous_state = EmailEnrollmentState(course_id, student_email)
 
     if previous_state.user:
-        user = User.objects.get(email=student_email)
-        CourseEnrollment.objects.get_or_create(course_id=course_id, user=user)
+        CourseEnrollment.enroll_by_email(student_email, course_id)
     else:
         cea, _ = CourseEnrollmentAllowed.objects.get_or_create(course_id=course_id, email=student_email)
         cea.auto_enroll = auto_enroll
@@ -91,7 +94,7 @@ def unenroll_email(course_id, student_email):
     previous_state = EmailEnrollmentState(course_id, student_email)
 
     if previous_state.enrollment:
-        CourseEnrollment.objects.get(course_id=course_id, user__email=student_email).delete()
+        CourseEnrollment.unenroll_by_email(student_email, course_id)
 
     if previous_state.allowed:
         CourseEnrollmentAllowed.objects.get(course_id=course_id, email=student_email).delete()

lms/djangoapps/instructor/offline_gradecalc.py

@@ -31,7 +31,10 @@ def offline_grade_calculation(course_id):
     '''
 
     tstart = time.time()
-    enrolled_students = User.objects.filter(courseenrollment__course_id=course_id).prefetch_related("groups").order_by('username')
+    enrolled_students = User.objects.filter(
+        courseenrollment__course_id=course_id,
+        courseenrollment__is_active=1
+    ).prefetch_related("groups").order_by('username')
 
     enc = MyEncoder()
 

lms/djangoapps/instructor/tests/test_api.py

@@ -98,7 +98,7 @@ class TestInstructorAPIDenyLevels(ModuleStoreTestCase, LoginEnrollmentTestCase):
     def setUp(self):
         self.user = UserFactory.create()
         self.course = CourseFactory.create()
-        CourseEnrollment.objects.create(user=self.user, course_id=self.course.id)
+        CourseEnrollment.enroll(self.user, self.course.id)
         self.client.login(username=self.user.username, password='test')
 
     def test_deny_students_update_enrollment(self):
@@ -161,9 +161,9 @@ class TestInstructorAPIEnrollment(ModuleStoreTestCase, LoginEnrollmentTestCase):
         self.client.login(username=self.instructor.username, password='test')
 
         self.enrolled_student = UserFactory()
-        CourseEnrollment.objects.create(
-            user=self.enrolled_student,
-            course_id=self.course.id
+        CourseEnrollment.enroll(
+            self.enrolled_student,
+            self.course.id
         )
         self.notenrolled_student = UserFactory()
 
@@ -237,7 +237,8 @@ class TestInstructorAPIEnrollment(ModuleStoreTestCase, LoginEnrollmentTestCase):
 
         self.assertEqual(
             self.enrolled_student.courseenrollment_set.filter(
-                course_id=self.course.id
+                course_id=self.course.id,
+                is_active=1,
             ).count(),
             0
         )
@@ -425,7 +426,7 @@ class TestInstructorAPILevelsDataDump(ModuleStoreTestCase, LoginEnrollmentTestCa
 
         self.students = [UserFactory() for _ in xrange(6)]
         for student in self.students:
-            CourseEnrollment.objects.create(user=student, course_id=self.course.id)
+            CourseEnrollment.enroll(student, self.course.id)
 
     def test_get_students_features(self):
         """
@@ -535,7 +536,7 @@ class TestInstructorAPIRegradeTask(ModuleStoreTestCase, LoginEnrollmentTestCase)
         self.client.login(username=self.instructor.username, password='test')
 
         self.student = UserFactory()
-        CourseEnrollment.objects.create(course_id=self.course.id, user=self.student)
+        CourseEnrollment.enroll(self.student, self.course.id)
 
         self.problem_urlname = 'robot-some-problem-urlname'
         self.module_to_reset = StudentModule.objects.create(
@@ -678,7 +679,7 @@ class TestInstructorAPITaskLists(ModuleStoreTestCase, LoginEnrollmentTestCase):
         self.client.login(username=self.instructor.username, password='test')
 
         self.student = UserFactory()
-        CourseEnrollment.objects.create(course_id=self.course.id, user=self.student)
+        CourseEnrollment.enroll(self.student, self.course.id)
 
         self.problem_urlname = 'robot-some-problem-urlname'
         self.module = StudentModule.objects.create(

lms/djangoapps/instructor/tests/test_enrollment.py

@@ -353,10 +353,7 @@ class SettableEnrollmentState(EmailEnrollmentState):
             user = UserFactory()
             email = user.email
             if self.enrollment:
-                cenr = CourseEnrollment.objects.create(
-                    user=user,
-                    course_id=course_id
-                )
+                cenr = CourseEnrollment.enroll(user, course_id)
                 return EnrollmentObjects(email, user, cenr, None)
             else:
                 return EnrollmentObjects(email, user, None, None)

lms/djangoapps/instructor/tests/test_legacy_enrollment.py

@@ -51,7 +51,13 @@ class TestInstructorEnrollsStudent(ModuleStoreTestCase, LoginEnrollmentTestCase)
 
         # Run the Un-enroll students command
         url = reverse('instructor_dashboard', kwargs={'course_id': course.id})
-        response = self.client.post(url, {'action': 'Unenroll multiple students', 'multiple_students': 'student0@test.com student1@test.com'})
+        response = self.client.post(
+            url,
+            {
+                'action': 'Unenroll multiple students',
+                'multiple_students': 'student0@test.com student1@test.com'
+            }
+        )
 
         # Check the page output
         self.assertContains(response, '<td>student0@test.com</td>')
@@ -60,12 +66,10 @@ class TestInstructorEnrollsStudent(ModuleStoreTestCase, LoginEnrollmentTestCase)
 
         # Check the enrollment table
         user = User.objects.get(email='student0@test.com')
-        ce = CourseEnrollment.objects.filter(course_id=course.id, user=user)
-        self.assertEqual(0, len(ce))
+        self.assertFalse(CourseEnrollment.is_enrolled(user, course.id))
 
         user = User.objects.get(email='student1@test.com')
-        ce = CourseEnrollment.objects.filter(course_id=course.id, user=user)
-        self.assertEqual(0, len(ce))
+        self.assertFalse(CourseEnrollment.is_enrolled(user, course.id))
 
         # Check the outbox
         self.assertEqual(len(mail.outbox), 0)
@@ -96,7 +100,7 @@ class TestInstructorEnrollsStudent(ModuleStoreTestCase, LoginEnrollmentTestCase)
         self.assertEqual(1, cea[0].auto_enroll)
 
         # Check there is no enrollment db entry other than for the other students
-        ce = CourseEnrollment.objects.filter(course_id=course.id)
+        ce = CourseEnrollment.objects.filter(course_id=course.id, is_active=1)
         self.assertEqual(4, len(ce))
 
         # Create and activate student accounts with same email
@@ -111,12 +115,10 @@ class TestInstructorEnrollsStudent(ModuleStoreTestCase, LoginEnrollmentTestCase)
 
         # Check students are enrolled
         user = User.objects.get(email='student1_1@test.com')
-        ce = CourseEnrollment.objects.filter(course_id=course.id, user=user)
-        self.assertEqual(1, len(ce))
+        self.assertTrue(CourseEnrollment.is_enrolled(user, course.id))
 
         user = User.objects.get(email='student1_2@test.com')
-        ce = CourseEnrollment.objects.filter(course_id=course.id, user=user)
-        self.assertEqual(1, len(ce))
+        self.assertTrue(CourseEnrollment.is_enrolled(user, course.id))
 
     def test_repeat_enroll(self):
         """
@@ -156,7 +158,7 @@ class TestInstructorEnrollsStudent(ModuleStoreTestCase, LoginEnrollmentTestCase)
         self.assertEqual(0, cea[0].auto_enroll)
 
         # Check there is no enrollment db entry other than for the setup instructor and students
-        ce = CourseEnrollment.objects.filter(course_id=course.id)
+        ce = CourseEnrollment.objects.filter(course_id=course.id, is_active=1)
         self.assertEqual(4, len(ce))
 
         # Create and activate student accounts with same email
@@ -171,11 +173,10 @@ class TestInstructorEnrollsStudent(ModuleStoreTestCase, LoginEnrollmentTestCase)
 
         # Check students are not enrolled
         user = User.objects.get(email='student2_1@test.com')
-        ce = CourseEnrollment.objects.filter(course_id=course.id, user=user)
-        self.assertEqual(0, len(ce))
+        self.assertFalse(CourseEnrollment.is_enrolled(user, course.id))
+
         user = User.objects.get(email='student2_2@test.com')
-        ce = CourseEnrollment.objects.filter(course_id=course.id, user=user)
-        self.assertEqual(0, len(ce))
+        self.assertFalse(CourseEnrollment.is_enrolled(user, course.id))
 
     def test_get_and_clean_student_list(self):
         """

lms/djangoapps/instructor/views/legacy.py

@@ -93,7 +93,7 @@ def instructor_dashboard(request, course_id):
         datatable = {'header': ['Statistic', 'Value'],
                      'title': 'Course Statistics At A Glance',
                      }
-        data = [['# Enrolled', CourseEnrollment.objects.filter(course_id=course_id).count()]]
+        data = [['# Enrolled', CourseEnrollment.objects.filter(course_id=course_id, is_active=1).count()]]
         data += [['Date', timezone.now().isoformat()]]
         data += compute_course_stats(course).items()
         if request.user.is_staff:
@@ -530,7 +530,10 @@ def instructor_dashboard(request, course_id):
     # DataDump
 
     elif 'Download CSV of all student profile data' in action:
-        enrolled_students = User.objects.filter(courseenrollment__course_id=course_id).order_by('username').select_related("profile")
+        enrolled_students = User.objects.filter(
+            courseenrollment__course_id=course_id,
+            courseenrollment__is_active=1,
+        ).order_by('username').select_related("profile")
         profkeys = ['name', 'language', 'location', 'year_of_birth', 'gender', 'level_of_education',
                     'mailing_address', 'goals']
         datatable = {'header': ['username', 'email'] + profkeys}
@@ -1002,7 +1005,10 @@ def get_student_grade_summary_data(request, course, course_id, get_grades=True,
     If get_raw_scores=True, then instead of grade summaries, the raw grades for all graded modules are returned.
 
     '''
-    enrolled_students = User.objects.filter(courseenrollment__course_id=course_id).prefetch_related("groups").order_by('username')
+    enrolled_students = User.objects.filter(
+        courseenrollment__course_id=course_id,
+        courseenrollment__is_active=1,
+    ).prefetch_related("groups").order_by('username')
 
     header = ['ID', 'Username', 'Full Name', 'edX email', 'External email']
     assignments = []
@@ -1053,7 +1059,10 @@ def gradebook(request, course_id):
     """
     course = get_course_with_access(request.user, course_id, 'staff', depth=None)
 
-    enrolled_students = User.objects.filter(courseenrollment__course_id=course_id).order_by('username').select_related("profile")
+    enrolled_students = User.objects.filter(
+        courseenrollment__course_id=course_id,
+        courseenrollment__is_active=1
+    ).order_by('username').select_related("profile")
 
     # TODO (vshnayder): implement pagination.
     enrolled_students = enrolled_students[:1000]   # HACK!
@@ -1110,7 +1119,7 @@ def _do_enroll_students(course, course_id, students, overload=False, auto_enroll
         for ce in todelete:
             if not has_access(ce.user, course, 'staff') and ce.user.email.lower() not in new_students_lc:
                 status[ce.user.email] = 'deleted'
-                ce.delete()
+                ce.deactivate()
             else:
                 status[ce.user.email] = 'is staff'
         ceaset = CourseEnrollmentAllowed.objects.filter(course_id=course_id)
@@ -1162,14 +1171,13 @@ def _do_enroll_students(course, course_id, students, overload=False, auto_enroll
             continue
 
         #Student has already registered
-        if CourseEnrollment.objects.filter(user=user, course_id=course_id):
+        if CourseEnrollment.is_enrolled(user, course_id):
             status[student] = 'already enrolled'
             continue
 
         try:
             #Not enrolled yet
-            ce = CourseEnrollment(user=user, course_id=course_id)
-            ce.save()
+            ce = CourseEnrollment.enroll(user, course_id)
             status[student] = 'added'
 
             if email_students:
@@ -1239,11 +1247,10 @@ def _do_unenroll_students(course_id, students, email_students=False):
 
             continue
 
-        ce = CourseEnrollment.objects.filter(user=user, course_id=course_id)
         #Will be 0 or 1 records as there is a unique key on user + course_id
-        if ce:
+        if CourseEnrollment.is_enrolled(user, course_id):
             try:
-                ce[0].delete()
+                CourseEnrollment.unenroll(user, course_id)
                 status[student] = "un-enrolled"
                 if email_students:
                     #User was enrolled