Merge pull request #480 from ankitjavalkar/toggle-mod

[Role based implementation] Allow moderator to switch between student and moderator roles

11 files changed, 418 insertions, 58 deletions

diff --git a/yaksh/evaluator_tests/test_simple_question_types.py b/yaksh/evaluator_tests/test_simple_question_types.py
index f7a6cf6..5edd545 100644
--- a/yaksh/evaluator_tests/test_simple_question_types.py
+++ b/yaksh/evaluator_tests/test_simple_question_types.py
@@ -1,6 +1,7 @@
 import unittest
 from datetime import datetime, timedelta
 from django.utils import timezone
+from django.contrib.auth.models import Group
 from textwrap import dedent
 import pytz
 from yaksh.models import User, Profile, Question, Quiz, QuestionPaper,\
@@ -8,7 +9,9 @@ from yaksh.models import User, Profile, Question, Quiz, QuestionPaper,\
     StringTestCase, McqTestCase, ArrangeTestCase
 
 
+
 def setUpModule():
+    mod_group = Group.objects.create(name='moderator')
     # Create user profile
     # Create User 1
     user = User.objects.create_user(username='demo_user_100',
@@ -46,6 +49,7 @@ def setUpModule():
 def tearDownModule():
     User.objects.filter(username__in=["demo_user_100", "demo_user_101"])\
                  .delete()
+    Group.objects.all().delete()
 
 
 class IntegerQuestionTestCases(unittest.TestCase):
diff --git a/yaksh/live_server_tests/load_test.py b/yaksh/live_server_tests/load_test.py
index 520bebe..e5ac068 100644
--- a/yaksh/live_server_tests/load_test.py
+++ b/yaksh/live_server_tests/load_test.py
@@ -1,8 +1,10 @@
 from threading import Thread
 from django.contrib.staticfiles.testing import StaticLiveServerTestCase
+from django.contrib.auth.models import User, Group, Permission
+from django.contrib.contenttypes.models import ContentType
 
 # Local imports
-from yaksh.models import User, Profile, Course
+from yaksh.models import User, Profile, Course, create_group
 from yaksh.code_server import ServerPool
 from yaksh import settings
 from .selenium_test import SeleniumTest
@@ -26,6 +28,10 @@ class YakshSeleniumTests(StaticLiveServerTestCase):
         cls.code_server_thread = t = Thread(target=code_server_pool.run)
         t.start()
 
+        app_label = 'yaksh'
+        group_name = 'moderator'
+        cls.group = create_group(group_name, app_label)
+
         cls.demo_student = User.objects.create_user(
             username='demo_student',
             password='demo_student',
@@ -45,7 +51,8 @@ class YakshSeleniumTests(StaticLiveServerTestCase):
         cls.demo_mod_profile = Profile.objects.create(
             user=cls.demo_mod,
             roll_number=0, institute='IIT',
-            department='Chemical', position='Moderator'
+            department='Chemical', position='Moderator',
+            is_moderator=True
         )
 
         course_obj = Course()
@@ -61,6 +68,7 @@ class YakshSeleniumTests(StaticLiveServerTestCase):
         cls.demo_mod.delete()
         cls.demo_mod_profile.delete()
         cls.demo_course.delete()
+        cls.group.delete()
 
         cls.code_server_pool.stop()
         cls.code_server_thread.join()
diff --git a/yaksh/management/commands/create_moderator.py b/yaksh/management/commands/create_moderator.py
index 86489d5..96276b5 100644
--- a/yaksh/management/commands/create_moderator.py
+++ b/yaksh/management/commands/create_moderator.py
@@ -7,7 +7,9 @@
 # django imports
 from django.core.management.base import BaseCommand, CommandError
 from django.contrib.auth.models import User, Group, Permission
-from django.contrib.contenttypes.models import ContentType
+
+# local imports
+from yaksh.models import create_group
 
 
 class Command(BaseCommand):
@@ -19,19 +21,9 @@ class Command(BaseCommand):
 
     def handle(self, *args, **options):
         app_label = 'yaksh'
-
-        try:
-            group = Group.objects.get(name='moderator')
-        except Group.DoesNotExist:
-            group = Group(name='moderator')
-            group.save()
-            # Get the models for the given app
-            content_types = ContentType.objects.filter(app_label=app_label)
-            # Get list of permissions for the models
-            permission_list = Permission.objects.filter(
-                content_type__in=content_types)
-            group.permissions.add(*permission_list)
-            group.save()
+        group_name = 'moderator'
+        group = create_group(group_name, app_label)
+        if group and isinstance(group, Group):
             self.stdout.write('Moderator group added successfully')
 
         if options['usernames']:
diff --git a/yaksh/models.py b/yaksh/models.py
index 1eca721..152289f 100644
--- a/yaksh/models.py
+++ b/yaksh/models.py
@@ -8,7 +8,7 @@ from ruamel.yaml.comments import CommentedMap
 from random import sample
 from collections import Counter
 from django.db import models
-from django.contrib.auth.models import User
+from django.contrib.auth.models import User, Group, Permission
 from django.contrib.contenttypes.models import ContentType
 from taggit.managers import TaggableManager
 from django.utils import timezone
@@ -92,6 +92,8 @@ test_status = (
 
 FIXTURES_DIR_PATH = os.path.join(settings.BASE_DIR, 'yaksh', 'fixtures')
 
+MOD_GROUP_NAME = 'moderator'
+
 
 def get_assignment_dir(instance, filename):
     upload_dir = instance.question_paper.quiz.description.replace(" ", "_")
@@ -135,6 +137,21 @@ def get_file_dir(instance, filename):
         upload_dir = instance.name.replace(" ", "_")
     return os.sep.join((upload_dir, filename))
 
+def create_group(group_name, app_label):
+    try:
+        group = Group.objects.get(name=group_name)
+    except Group.DoesNotExist:
+        group = Group(name=group_name)
+        group.save()
+        # Get the models for the given app
+        content_types = ContentType.objects.filter(app_label=app_label)
+        # Get list of permissions for the models
+        permission_list = Permission.objects.filter(
+            content_type__in=content_types)
+        group.permissions.add(*permission_list)
+        group.save()
+    return group
+
 
 ###############################################################################
 class CourseManager(models.Manager):
@@ -982,6 +999,7 @@ class Profile(models.Model):
     institute = models.CharField(max_length=128)
     department = models.CharField(max_length=64)
     position = models.CharField(max_length=64)
+    is_moderator = models.BooleanField(default=False)
     timezone = models.CharField(
         max_length=64,
         default=pytz.utc.zone,
@@ -1000,6 +1018,20 @@ class Profile(models.Model):
             os.chmod(user_dir, stat.S_IRWXU | stat.S_IRWXG | stat.S_IRWXO)
         return user_dir
 
+    def _toggle_moderator_group(self, group_name):
+        group = Group.objects.get(name=group_name)
+        if self.is_moderator:
+            self.user.groups.add(group)
+        else:
+            self.user.groups.remove(group)
+
+    def save(self, *args, **kwargs):
+        if self.pk is not None:
+            old_profile = Profile.objects.get(pk=self.pk)
+            if old_profile.is_moderator != self.is_moderator:
+                self._toggle_moderator_group(group_name=MOD_GROUP_NAME)
+        super(Profile, self).save(*args, **kwargs)
+
     def __str__(self):
         return '%s' % (self.user.get_full_name())
 
diff --git a/yaksh/templates/yaksh/moderator_dashboard.html b/yaksh/templates/yaksh/moderator_dashboard.html
index 17a4924..c848074 100644
--- a/yaksh/templates/yaksh/moderator_dashboard.html
+++ b/yaksh/templates/yaksh/moderator_dashboard.html
@@ -8,7 +8,10 @@
 
 {% block content %}
 
-<center><h4>List of quizzes! Click on the given links to have a look at answer papers for a quiz.</h4></center>
+<center><h4 class="pull-left">List of quizzes! Click on the given links to have a look at answer papers for a quiz.</h4></center>
+<a href="{{URL_ROOT}}/exam/toggle_moderator/" class="btn btn-primary pull-right">
+  Switch To Student
+</a>
 <table class="table table-bordered">
     <th>Courses</th>
     <th>Quizzes</th>
diff --git a/yaksh/templates/yaksh/quizzes_user.html b/yaksh/templates/yaksh/quizzes_user.html
index 78cdc48..68044da 100644
--- a/yaksh/templates/yaksh/quizzes_user.html
+++ b/yaksh/templates/yaksh/quizzes_user.html
@@ -7,6 +7,13 @@
             <center>{{ msg }}</center>
         </div>
     {% endif %}
+    {% if user.profile.is_moderator %}
+        <div class="row">
+            <a href="{{URL_ROOT}}/exam/toggle_moderator/" class="btn btn-primary pull-right" style="margin-top: 20px; margin-bottom: 20px;">
+              Switch To Moderator
+            </a>
+        </div>
+    {% endif %}
     {% if 'Enrolled Courses' not in title%}
         <div class="row well">
             <form action="{{ URL_ROOT }}/exam/quizzes/" method="post" id="custom-search-form" class="form-search form-horizontal">
diff --git a/yaksh/templatetags/test_custom_filters.py b/yaksh/templatetags/test_custom_filters.py
index e8d1d61..eb1f0fb 100644
--- a/yaksh/templatetags/test_custom_filters.py
+++ b/yaksh/templatetags/test_custom_filters.py
@@ -1,6 +1,7 @@
 import unittest
 from datetime import datetime, timedelta
 from django.utils import timezone
+from django.contrib.auth.models import Group
 import pytz
 
 # local imports
@@ -15,6 +16,8 @@ from yaksh.templatetags.custom_filters import (completed, inprogress,
 
 
 def setUpModule():
+    mod_group = Group.objects.create(name='moderator')
+
     # Create user profile
     teacher = User.objects.create_user(
       username='teacher2000', password='demo',
@@ -52,7 +55,7 @@ def setUpModule():
 
 def tearDownModule():
     User.objects.get(username="teacher2000").delete()
-
+    Group.objects.all().delete()
 
 class CustomFiltersTestCases(unittest.TestCase):
 
diff --git a/yaksh/test_models.py b/yaksh/test_models.py
index 403dfb4..14d5197 100644
--- a/yaksh/test_models.py
+++ b/yaksh/test_models.py
@@ -1,9 +1,10 @@
 import unittest
+from django.contrib.auth.models import Group
 from yaksh.models import User, Profile, Question, Quiz, QuestionPaper,\
     QuestionSet, AnswerPaper, Answer, Course, StandardTestCase,\
     StdIOBasedTestCase, FileUpload, McqTestCase, AssignmentUpload,\
     LearningModule, LearningUnit, Lesson, LessonFile, CourseStatus, \
-    TestCaseOrder
+    TestCaseOrder, create_group
 from yaksh.code_server import (
     ServerPool, get_result as get_result_from_code_server
     )
@@ -24,6 +25,8 @@ from yaksh import settings
 
 
 def setUpModule():
+    mod_group = Group.objects.create(name='moderator')
+
     # create user profile
     user = User.objects.create_user(username='creator',
                                     password='demo',
@@ -111,7 +114,16 @@ def tearDownModule():
     LearningUnit.objects.all().delete()
     LearningModule.objects.all().delete()
     AnswerPaper.objects.all().delete()
+    Group.objects.all().delete()
+
 
+###############################################################################
+class GlobalMethodsTestCases(unittest.TestCase):
+    def test_create_group_when_group_exists(self):
+        self.assertEqual(
+            create_group('moderator', 'yaksh'),
+            Group.objects.get(name='moderator')
+        )
 
 ###############################################################################
 class LessonTestCases(unittest.TestCase):
diff --git a/yaksh/test_views.py b/yaksh/test_views.py
index 06a4fa3..899ed31 100644
--- a/yaksh/test_views.py
+++ b/yaksh/test_views.py
@@ -14,6 +14,7 @@ from django.contrib.auth import authenticate
 from django.core.urlresolvers import reverse
 from django.test import TestCase
 from django.test import Client
+from django.http import Http404
 from django.utils import timezone
 from django.core import mail
 from django.conf import settings
@@ -27,15 +28,18 @@ from yaksh.models import (
     FloatTestCase, FIXTURES_DIR_PATH, LearningModule, LearningUnit, Lesson,
     LessonFile, CourseStatus, dict_to_yaml
 )
+from yaksh.views import add_as_moderator
 from yaksh.decorators import user_has_profile
 
 
 class TestUserRegistration(TestCase):
     def setUp(self):
         self.client = Client()
+        self.mod_group = Group.objects.create(name='moderator')
 
     def tearDown(self):
         self.registered_user.delete()
+        self.mod_group.delete()
 
     def test_register_user_post(self):
         self.client.post(
@@ -63,6 +67,7 @@ class TestUserRegistration(TestCase):
 class TestProfile(TestCase):
     def setUp(self):
         self.client = Client()
+        self.mod_group = Group.objects.create(name='moderator')
 
         # Create User without profile
         self.user1_plaintext_pass = 'demo1'
@@ -95,6 +100,7 @@ class TestProfile(TestCase):
         self.client.logout()
         self.user1.delete()
         self.user2.delete()
+        self.mod_group.delete()
 
     def test_user_has_profile_for_user_without_profile(self):
         """
@@ -302,6 +308,7 @@ class TestProfile(TestCase):
 class TestStudentDashboard(TestCase):
     def setUp(self):
         self.client = Client()
+        self.mod_group = Group.objects.create(name='moderator')
 
         # student
         self.student_plaintext_pass = 'student'
@@ -365,6 +372,7 @@ class TestStudentDashboard(TestCase):
         self.client.logout()
         self.user.delete()
         self.course.delete()
+        self.mod_group.delete()
 
     def test_student_dashboard_denies_anonymous_user(self):
         """
@@ -467,7 +475,7 @@ class TestMonitor(TestCase):
             password=self.user_plaintext_pass,
             first_name='first_name',
             last_name='last_name',
-            email='demo@test.com'
+            email='demo@test.com',
         )
 
         Profile.objects.create(
@@ -476,7 +484,8 @@ class TestMonitor(TestCase):
             institute='IIT',
             department='Chemical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
 
         # Create Student
@@ -561,6 +570,7 @@ class TestMonitor(TestCase):
         self.new_answer.delete()
         self.learning_module.delete()
         self.learning_unit.delete()
+        self.mod_group.delete()
 
     def test_monitor_denies_student(self):
         """
@@ -661,7 +671,8 @@ class TestGradeUser(TestCase):
             institute='IIT',
             department='Chemical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
 
         # Create Student
@@ -877,7 +888,8 @@ class TestDownloadAssignment(TestCase):
             institute='IIT',
             department='Chemical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
 
         # Add to moderator group
@@ -957,6 +969,7 @@ class TestDownloadAssignment(TestCase):
         self.course.delete()
         self.learning_module.delete()
         self.learning_unit.delete()
+        self.mod_group.delete()
         dir_name = self.quiz.description.replace(" ", "_")
         file_path = os.sep.join((settings.MEDIA_ROOT, dir_name))
         if os.path.exists(file_path):
@@ -1052,7 +1065,8 @@ class TestAddQuiz(TestCase):
             institute='IIT',
             department='Chemical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
 
         # Create Student
@@ -1096,6 +1110,7 @@ class TestAddQuiz(TestCase):
         self.quiz.delete()
         self.exercise.delete()
         self.course.delete()
+        self.mod_group.delete()
 
     def test_add_quiz_denies_anonymous(self):
         """
@@ -1330,6 +1345,141 @@ class TestAddQuiz(TestCase):
         self.assertEqual(response.context['quizzes'][0], self.quiz)
         self.assertTemplateUsed(response, "yaksh/courses.html")
 
+class TestAddAsModerator(TestCase):
+    def setUp(self):
+        self.client = Client()
+        self.mod_group = Group.objects.create(name='moderator')
+        # Create Moderator with profile
+        self.user_plaintext_pass = 'demo'
+        self.user = User.objects.create_user(
+            username='demo_user',
+            password=self.user_plaintext_pass,
+            first_name='first_name',
+            last_name='last_name',
+            email='demo@test.com'
+        )
+
+        Profile.objects.create(
+            user=self.user,
+            roll_number=10,
+            institute='IIT',
+            department='Chemical',
+            position='Moderator',
+            timezone='UTC',
+            is_moderator=True
+        )
+
+        self.course = Course.objects.create(
+            name="Python Course",
+            enrollment="Enroll Request", creator=self.user
+        )
+
+        self.mod_group.delete()
+
+    def tearDown(self):
+        self.client.logout()
+        self.user.delete()
+
+    def test_add_as_moderator_group_does_not_exist(self):
+        """
+        If group does not exist return 404
+        """
+        self.client.login(
+            username=self.user.username,
+            password=self.user_plaintext_pass
+        )
+
+        response = self.client.get(
+            reverse('yaksh:add_teacher',
+                    kwargs={'course_id': self.course.id}
+                    ),
+            follow=True
+        )
+        self.assertEqual(response.status_code, 404)
+        with self.assertRaises(Http404):
+            add_as_moderator(self.user, 'moderator')
+
+class TestToggleModerator(TestCase):
+    def setUp(self):
+        self.client = Client()
+
+        self.mod_group = Group.objects.create(name='moderator')
+
+        # Create Moderator with profile
+        self.user_plaintext_pass = 'demo'
+        self.user = User.objects.create_user(
+            username='demo_user',
+            password=self.user_plaintext_pass,
+            first_name='first_name',
+            last_name='last_name',
+            email='demo@test.com'
+        )
+
+        Profile.objects.create(
+            user=self.user,
+            roll_number=10,
+            institute='IIT',
+            department='Chemical',
+            position='Moderator',
+            timezone='UTC',
+            is_moderator=True
+        )
+
+        # Create Student
+        self.student_plaintext_pass = 'demo_student'
+        self.student = User.objects.create_user(
+            username='demo_student',
+            password=self.student_plaintext_pass,
+            first_name='student_first_name',
+            last_name='student_last_name',
+            email='demo_student@test.com'
+        )
+
+        Profile.objects.create(
+            user=self.student,
+            roll_number=10,
+            institute='IIT',
+            department='Chemical',
+            position='Student',
+            timezone='UTC',
+        )
+
+        # Add to moderator group
+        self.mod_group.user_set.add(self.user)
+
+        self.course = Course.objects.create(
+            name="Python Course",
+            enrollment="Enroll Request", creator=self.user
+            )
+
+    def tearDown(self):
+        self.client.logout()
+        self.user.delete()
+        self.student.delete()
+        self.course.delete()
+        self.mod_group.delete()
+
+    def test_toggle_for_moderator(self):
+        self.client.login(
+            username=self.user.username,
+            password=self.user_plaintext_pass
+        )
+        response = self.client.get(
+            reverse('yaksh:toggle_moderator')
+        )
+        self.assertEqual(response.status_code, 302)
+        self.assertEquals(self.user.groups.all().count(), 0)
+
+    def test_toggle_for_student(self):
+        self.client.login(
+            username=self.student.username,
+            password=self.student_plaintext_pass
+        )
+        response = self.client.get(
+            reverse('yaksh:toggle_moderator')
+        )
+
+        self.assertEqual(response.status_code, 404)
 
 class TestAddTeacher(TestCase):
     def setUp(self):
@@ -1338,6 +1488,16 @@ class TestAddTeacher(TestCase):
         self.mod_group = Group.objects.create(name='moderator')
         tzone = pytz.timezone('UTC')
 
+        # Create User with no profile
+        self.user_no_profile_plaintext_pass = 'demo_no_profile'
+        self.user_no_profile = User.objects.create_user(
+            username='demo_user_no_profile',
+            password=self.user_no_profile_plaintext_pass,
+            first_name='first_name_no_profile',
+            last_name='last_name_no_profile',
+            email='demo_no_profile@test.com'
+        )
+
         # Create Moderator with profile
         self.user_plaintext_pass = 'demo'
         self.user = User.objects.create_user(
@@ -1354,7 +1514,8 @@ class TestAddTeacher(TestCase):
             institute='IIT',
             department='Chemical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
 
         # Create Student
@@ -1400,6 +1561,24 @@ class TestAddTeacher(TestCase):
         self.quiz.delete()
         self.pre_req_quiz.delete()
         self.course.delete()
+        self.mod_group.delete()
+
+    def test_add_teacher_denies_no_profile(self):
+        """
+        If not moderator redirect to login page
+        """
+        self.client.login(
+            username=self.user_no_profile.username,
+            password=self.user_no_profile_plaintext_pass
+        )
+
+        response = self.client.get(
+            reverse('yaksh:add_teacher',
+                    kwargs={'course_id': self.course.id}
+                    ),
+            follow=True
+        )
+        self.assertEqual(response.status_code, 404)
 
     def test_add_teacher_denies_anonymous(self):
         """
@@ -1565,6 +1744,7 @@ class TestRemoveTeacher(TestCase):
         self.quiz.delete()
         self.pre_req_quiz.delete()
         self.course.delete()
+        self.mod_group.delete()
 
     def test_remove_teacher_denies_anonymous(self):
         """
@@ -1668,7 +1848,8 @@ class TestCourses(TestCase):
             institute='IIT',
             department='Chemical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
 
         self.user2_plaintext_pass = 'demo2'
@@ -1686,7 +1867,8 @@ class TestCourses(TestCase):
             institute='IIT',
             department='Aeronautical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
 
         # Create Student
@@ -1716,6 +1898,16 @@ class TestCourses(TestCase):
             email='demo_teacher@test.com'
         )
 
+        Profile.objects.create(
+            user=self.teacher,
+            roll_number=10,
+            institute='IIT',
+            department='Aeronautical',
+            position='Moderator',
+            timezone='UTC',
+            is_moderator=True
+        )
+
         # Add to moderator group
         self.mod_group.user_set.add(self.user1)
         self.mod_group.user_set.add(self.user2)
@@ -1771,6 +1963,7 @@ class TestCourses(TestCase):
         self.user2.delete()
         self.student.delete()
         self.teacher.delete()
+        self.mod_group.delete()
 
     def test_courses_denies_anonymous(self):
         """
@@ -2087,7 +2280,8 @@ class TestAddCourse(TestCase):
             institute='IIT',
             department='Chemical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
 
         # Create a teacher
@@ -2106,7 +2300,8 @@ class TestAddCourse(TestCase):
             institute='IIT',
             department='Chemical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
 
         # Create Student
@@ -2154,6 +2349,7 @@ class TestAddCourse(TestCase):
         self.quiz.delete()
         self.pre_req_quiz.delete()
         self.course.delete()
+        self.mod_group.delete()
 
     def test_add_course_denies_anonymous(self):
         """
@@ -2266,7 +2462,8 @@ class TestCourseDetail(TestCase):
             institute='IIT',
             department='Chemical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
 
         self.user2_plaintext_pass = 'demo2'
@@ -2284,7 +2481,8 @@ class TestCourseDetail(TestCase):
             institute='IIT',
             department='Aeronautical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
 
         # Create Student
@@ -2331,6 +2529,7 @@ class TestCourseDetail(TestCase):
         self.user2.delete()
         self.student.delete()
         self.user1_course.delete()
+        self.mod_group.delete()
 
     def test_upload_users_with_correct_csv(self):
         # Given
@@ -2849,7 +3048,8 @@ class TestEnrollRequest(TestCase):
             institute='IIT',
             department='Chemical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
 
         self.user2_plaintext_pass = 'demo2'
@@ -2867,7 +3067,8 @@ class TestEnrollRequest(TestCase):
             institute='IIT',
             department='Aeronautical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
 
         # Create Student
@@ -2895,6 +3096,7 @@ class TestEnrollRequest(TestCase):
         self.user2.delete()
         self.student.delete()
         self.course.delete()
+        self.mod_group.delete()
 
     def test_enroll_request_denies_anonymous(self):
         """
@@ -3118,7 +3320,8 @@ class TestSelfEnroll(TestCase):
             institute='IIT',
             department='Chemical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
 
         self.user2_plaintext_pass = 'demo2'
@@ -3136,7 +3339,8 @@ class TestSelfEnroll(TestCase):
             institute='IIT',
             department='Aeronautical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
 
         # Create Student
@@ -3164,6 +3368,7 @@ class TestSelfEnroll(TestCase):
         self.user2.delete()
         self.student.delete()
         self.course.delete()
+        self.mod_group.delete()
 
     def test_self_enroll_denies_anonymous(self):
         response = self.client.get(
@@ -3228,7 +3433,8 @@ class TestGrader(TestCase):
             institute='IIT',
             department='Chemical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
 
         self.user2_plaintext_pass = 'demo2'
@@ -3246,7 +3452,8 @@ class TestGrader(TestCase):
             institute='IIT',
             department='Aeronautical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
 
         # Create Student
@@ -3295,6 +3502,7 @@ class TestGrader(TestCase):
         Quiz.objects.all().delete()
         QuestionPaper.objects.all().delete()
         AnswerPaper.objects.all().delete()
+        self.mod_group.delete()
 
     def test_grader_denies_anonymous(self):
         # Given
@@ -3444,6 +3652,8 @@ class TestGrader(TestCase):
 
 class TestPasswordReset(TestCase):
     def setUp(self):
+        self.mod_group = Group.objects.create(name='moderator')
+
         # Create User with profile
         self.user1_plaintext_pass = 'demo1'
         self.user1 = User.objects.create_user(
@@ -3465,6 +3675,7 @@ class TestPasswordReset(TestCase):
 
     def tearDown(self):
         self.user1.delete()
+        self.mod_group.delete()
 
     def test_password_reset_post(self):
         """
@@ -3553,7 +3764,8 @@ class TestModeratorDashboard(TestCase):
             institute='IIT',
             department='Chemical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
 
         self.mod_no_profile_plaintext_pass = 'demo2'
@@ -3654,6 +3866,7 @@ class TestModeratorDashboard(TestCase):
         self.question_paper.delete()
         self.answerpaper.delete()
         self.new_answer.delete()
+        self.mod_group.delete()
 
     def test_moderator_dashboard_denies_student(self):
         """
@@ -3740,6 +3953,8 @@ class TestUserLogin(TestCase):
     def setUp(self):
         self.client = Client()
 
+        self.mod_group = Group.objects.create(name='moderator')
+
         # Create Moderator with profile
         self.user1_plaintext_pass = 'demo1'
         self.user1 = User.objects.create_user(
@@ -3763,6 +3978,7 @@ class TestUserLogin(TestCase):
         self.client.logout()
         settings.IS_DEVELOPMENT = True
         self.user1.delete()
+        self.mod_group.delete()
 
     def test_successful_user_login(self):
         """
@@ -3801,7 +4017,7 @@ class TestUserLogin(TestCase):
         self.assertTemplateUsed(response, "yaksh/activation_status.html")
 
 
-class TestDownloadcsv(TestCase):
+class TestDownloadCsv(TestCase):
     def setUp(self):
         self.client = Client()
         tzone = pytz.timezone("utc")
@@ -3841,7 +4057,8 @@ class TestDownloadcsv(TestCase):
             institute='IIT',
             department='Chemical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
         self.mod_group.user_set.add(self.user)
         self.course = Course.objects.create(
@@ -3895,6 +4112,7 @@ class TestDownloadcsv(TestCase):
         self.student.delete()
         self.quiz.delete()
         self.course.delete()
+        self.mod_group.delete()
 
     def test_download_csv_denies_student(self):
         """
@@ -4036,7 +4254,8 @@ class TestShowQuestions(TestCase):
             institute='IIT',
             department='Chemical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
         self.mod_group.user_set.add(self.user)
         self.question = Question.objects.create(
@@ -4080,6 +4299,13 @@ class TestShowQuestions(TestCase):
                                               yaml_question_2.encode("utf-8")
                                               )
 
+    def tearDown(self):
+        self.client.logout()
+        User.objects.all().delete()
+        Profile.objects.all().delete()
+        Question.objects.all().delete()
+        Group.objects.all().delete()
+
     def test_show_questions_denies_student(self):
         """
             Check show questions denies student
@@ -4352,7 +4578,8 @@ class TestShowStatistics(TestCase):
             institute='IIT',
             department='Chemical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
 
         # Create Student
@@ -4429,6 +4656,7 @@ class TestShowStatistics(TestCase):
         self.question.delete()
         self.question_paper.delete()
         self.new_answer.delete()
+        self.mod_group.delete()
 
     def test_show_statistics_denies_student(self):
         """
@@ -4514,7 +4742,8 @@ class TestQuestionPaper(TestCase):
             institute='IIT',
             department='Chemical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
 
         self.student_plaintext_pass = 'demo'
@@ -4568,7 +4797,8 @@ class TestQuestionPaper(TestCase):
             institute='IIT',
             department='Chemical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
 
         # Add to moderator group
@@ -4739,6 +4969,7 @@ class TestQuestionPaper(TestCase):
         self.question_paper.delete()
         self.learning_module.delete()
         self.learning_unit.delete()
+        self.mod_group.delete()
 
     def test_preview_questionpaper_correct(self):
         self.client.login(
@@ -5262,7 +5493,8 @@ class TestLearningModule(TestCase):
             institute='IIT',
             department='Chemical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
 
         # Create a student
@@ -5282,7 +5514,17 @@ class TestLearningModule(TestCase):
             password=self.teacher_plaintext_pass,
             first_name='first_name',
             last_name='last_name',
-            email='demo@student.com'
+            email='demo@teacher.com',
+        )
+
+        Profile.objects.create(
+            user=self.teacher,
+            roll_number=10,
+            institute='IIT',
+            department='Chemical',
+            position='Moderator',
+            timezone='UTC',
+            is_moderator=True
         )
 
         # Add to moderator group
@@ -5345,6 +5587,7 @@ class TestLearningModule(TestCase):
         self.course.delete()
         self.learning_unit.delete()
         self.learning_module.delete()
+        self.mod_group.delete()
 
     def test_add_new_module_denies_non_moderator(self):
         self.client.login(
@@ -5643,7 +5886,8 @@ class TestLessons(TestCase):
             institute='IIT',
             department='Chemical',
             position='Moderator',
-            timezone='UTC'
+            timezone='UTC',
+            is_moderator=True
         )
 
         # Create a student
@@ -5656,6 +5900,15 @@ class TestLessons(TestCase):
             email='demo@student.com'
         )
 
+        Profile.objects.create(
+            user=self.student,
+            roll_number=10,
+            institute='IIT',
+            department='Chemical',
+            position='student',
+            timezone='UTC'
+        )
+
         # Create a teacher to add to the course
         self.teacher_plaintext_pass = 'demo_teacher'
         self.teacher = User.objects.create_user(
@@ -5666,6 +5919,16 @@ class TestLessons(TestCase):
             email='demo@student.com'
         )
 
+        Profile.objects.create(
+            user=self.teacher,
+            roll_number=10,
+            institute='IIT',
+            department='Chemical',
+            position='Moderator',
+            timezone='UTC',
+            is_moderator=True
+        )
+
         # Add to moderator group
         self.mod_group.user_set.add(self.user)
         self.mod_group.user_set.add(self.teacher)
@@ -5713,6 +5976,7 @@ class TestLessons(TestCase):
         self.learning_module2.delete()
         self.lesson.delete()
         self.lesson2.delete()
+        self.mod_group.delete()
 
     def test_edit_lesson_denies_non_moderator(self):
         """ Student should not be allowed to edit lesson """
diff --git a/yaksh/urls.py b/yaksh/urls.py
index 6e6b8c1..8f3401b 100644
--- a/yaksh/urls.py
+++ b/yaksh/urls.py
@@ -8,6 +8,7 @@ urlpatterns = [
     url(r'^update_email/$', views.update_email, name="update_email"),
     url(r'^activate/(?P<key>.+)$', views.activate_user, name="activate"),
     url(r'^new_activation/$', views.new_activation, name='new_activation'),
+    url(r'^toggle_moderator/$', views.toggle_moderator_role, name='toggle_moderator'),
     url(r'^quizzes/$', views.quizlist_user, name='quizlist_user'),
     url(r'^quizzes/(?P<enrolled>\w+)/$', views.quizlist_user,
         name='quizlist_user'),
diff --git a/yaksh/views.py b/yaksh/views.py
index c6b1184..ecd7efd 100644
--- a/yaksh/views.py
+++ b/yaksh/views.py
@@ -30,7 +30,7 @@ from yaksh.code_server import get_result as get_result_from_code_server
 from yaksh.models import (
     Answer, AnswerPaper, AssignmentUpload, Course, FileUpload, Profile,
     QuestionPaper, QuestionSet, Quiz, Question, TestCase, User,
-    FIXTURES_DIR_PATH, Lesson, LessonFile, LearningUnit, LearningModule,
+    FIXTURES_DIR_PATH, MOD_GROUP_NAME, Lesson, LessonFile, LearningUnit, LearningModule,
     CourseStatus
 )
 from yaksh.forms import (
@@ -63,18 +63,27 @@ def my_render_to_response(request, template, context=None, **kwargs):
     return render(request, template, context, **kwargs)
 
 
-def is_moderator(user):
+def is_moderator(user, group_name=MOD_GROUP_NAME):
     """Check if the user is having moderator rights"""
-    if user.groups.filter(name='moderator').exists():
-        return True
+    try:
+        group = Group.objects.get(name=group_name)
+        return user.profile.is_moderator and user in group.user_set.all()
+    except Profile.DoesNotExist:
+        return False
+    except Group.DoesNotExist:
+        return False
 
 
-def add_to_group(users):
+def add_as_moderator(users, group_name=MOD_GROUP_NAME):
     """ add users to moderator group """
-    group = Group.objects.get(name="moderator")
+    try:
+        group = Group.objects.get(name=group_name)
+    except Group.DoesNotExist:
+        raise Http404('The Group {0} does not exist.'.format(group_name))
     for user in users:
         if not is_moderator(user):
-            user.groups.add(group)
+            user.profile.is_moderator = True
+            user.profile.save()
 
 
 CSV_FIELDS = ['name', 'username', 'roll_number', 'institute', 'department',
@@ -163,8 +172,10 @@ def quizlist_user(request, enrolled=None, msg=None):
         )
         title = 'All Courses'
 
-    context = {'user': user, 'courses': courses, 'title': title,
-               'msg': msg}
+    context = {
+        'user': user, 'courses': courses,
+        'title': title, 'msg': msg
+    }
 
     return my_render_to_response(request, "yaksh/quizzes_user.html", context)
 
@@ -1757,6 +1768,29 @@ def search_teacher(request, course_id):
 
 @login_required
 @email_verified
+def toggle_moderator_role(request):
+    """ Allow moderator to switch to student and back """
+
+    user = request.user
+
+    try:
+        group = Group.objects.get(name='moderator')
+    except Group.DoesNotExist:
+        raise Http404('The Moderator group does not exist')
+
+    if not user.profile.is_moderator:
+        raise Http404('You are not allowed to view this page!')
+
+    if user not in group.user_set.all():
+        group.user_set.add(user)
+    else:
+        group.user_set.remove(user)
+
+    return my_redirect('/exam/')
+
+
+@login_required
+@email_verified
 def add_teacher(request, course_id):
     """ add teachers to the course """
 
@@ -1775,7 +1809,7 @@ def add_teacher(request, course_id):
     if request.method == 'POST':
         teacher_ids = request.POST.getlist('check')
         teachers = User.objects.filter(id__in=teacher_ids)
-        add_to_group(teachers)
+        add_as_moderator(teachers)
         course.add_teachers(*teachers)
         context['status'] = True
         context['teachers_added'] = teachers