notification_prefs: add ajax endpoint to get preference status

lms/djangoapps/notification_prefs/tests.py

+import json
+
 from django.contrib.auth.models import AnonymousUser
 from django.core.exceptions import PermissionDenied
 from django.http import Http404
@@ -7,7 +9,7 @@ from django.test.utils import override_settings
 from mock import Mock, patch
 
 from notification_prefs import NOTIFICATION_PREF_KEY
-from notification_prefs.views import ajax_enable, ajax_disable, unsubscribe
+from notification_prefs.views import ajax_enable, ajax_disable, ajax_status, unsubscribe
 from student.tests.factories import UserFactory
 from user_api.models import UserPreference
 
@@ -57,6 +59,34 @@ class NotificationPrefViewTest(TestCase):
             UserPreference.objects.filter(user=user, key=NOTIFICATION_PREF_KEY).exists()
         )
 
+    # AJAX status view
+
+    def test_ajax_status_get_0(self):
+        request = self.request_factory.get("dummy")
+        request.user = self.user
+        response = ajax_status(request)
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(json.loads(response.content), {"status":0})
+
+    def test_ajax_status_get_1(self):
+        self.create_prefs()
+        request = self.request_factory.get("dummy")
+        request.user = self.user
+        response = ajax_status(request)
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(json.loads(response.content), {"status":1})
+
+    def test_ajax_status_post(self):
+        request = self.request_factory.post("dummy")
+        request.user = self.user
+        response = ajax_status(request)
+        self.assertEqual(response.status_code, 405)
+
+    def test_ajax_status_anon_user(self):
+        request = self.request_factory.get("dummy")
+        request.user = AnonymousUser()
+        self.assertRaises(PermissionDenied, ajax_status, request)
+
     # AJAX enable view
 
     def test_ajax_enable_get(self):

lms/djangoapps/notification_prefs/views.py

 from base64 import urlsafe_b64encode, urlsafe_b64decode
 from hashlib import sha256
+import json
 
 from Crypto.Cipher import AES
 from Crypto import Random
@@ -131,7 +132,7 @@ def ajax_disable(request):
 
     return HttpResponse(status=204)
 
-@require_POST
+@require_GET
 def ajax_status(request):
     """
     A view that sends notifications status for the authenticated user
@@ -142,22 +143,12 @@ def ajax_status(request):
     if not request.user.is_authenticated():
         raise PermissionDenied
 
-   prefs UserPreference.objects.get(
+    qs = UserPreference.objects.filter(
         user=request.user,
-        key=NOTIFICATION_PREF_KEY,
-        defaults={
-            "value": UsernameCipher.encrypt(request.user.username)
-        }
+        key=NOTIFICATION_PREF_KEY
     )
 
-    if prefs
-        answer = true
-    else
-        answer = false
-
-    return utils.JsonResponse({
-        'status': answer
-    })
+    return HttpResponse(json.dumps({"status":len(qs)}), content_type="application/json")
 
 
 @require_GET