Add a new user API for the notifier

This new endpoint is designed specifically to fill the needs of the
notifier and should not be used by other clients.

lms/djangoapps/notifier_api/models.py

+# Django requires this module.

lms/djangoapps/notifier_api/serializers.py

+from django.contrib.auth.models import User
+from rest_framework import serializers
+
+from course_groups.cohorts import is_course_cohorted
+from notification_prefs import NOTIFICATION_PREF_KEY
+from lang_pref import LANGUAGE_KEY
+
+
+class NotifierUserSerializer(serializers.ModelSerializer):
+    """
+    A serializer containing all information about a user needed by the notifier
+    (namely the user's name, email address, notification and language
+    preferences, and course enrollment and cohort information).
+
+    Because these pieces of information reside in different tables, this is
+    designed to work well with prefetch_related and select_related, which
+    require the use of all() instead of get() or filter(). The following fields
+    should be prefetched on the user objects being serialized:
+     * profile
+     * preferences
+     * courseenrollment_set
+     * course_groups
+     * roles__permissions
+    """
+    name = serializers.SerializerMethodField("get_name")
+    preferences = serializers.SerializerMethodField("get_preferences")
+    course_info = serializers.SerializerMethodField("get_course_info")
+
+    def get_name(self, user):
+        return user.profile.name
+
+    def get_preferences(self, user):
+        return {
+            pref.key: pref.value
+            for pref
+            in user.preferences.all()
+            if pref.key in [LANGUAGE_KEY, NOTIFICATION_PREF_KEY]
+        }
+
+    def get_course_info(self, user):
+        cohort_id_map = {
+            cohort.course_id: cohort.id
+            for cohort in user.course_groups.all()
+        }
+        see_all_cohorts_set = {
+            role.course_id
+            for role in user.roles.all()
+            for perm in role.permissions.all() if perm.name == "see_all_cohorts"
+        }
+        return {
+            unicode(enrollment.course_id): {
+                "cohort_id": cohort_id_map.get(enrollment.course_id),
+                "see_all_cohorts": (
+                    enrollment.course_id in see_all_cohorts_set or
+                    not is_course_cohorted(enrollment.course_id)
+                ),
+            }
+            for enrollment in user.courseenrollment_set.all() if enrollment.is_active
+        }
+
+    class Meta:
+        model = User
+        fields = ("id", "email", "name", "preferences", "course_info")
+        read_only_fields = ("id", "email")

lms/djangoapps/notifier_api/tests.py

+import itertools
+
+import ddt
+from django.conf import settings
+from django.test.client import RequestFactory
+from django.test.utils import override_settings
+
+from course_groups.models import CourseUserGroup
+from django_comment_common.models import Role, Permission
+from lang_pref import LANGUAGE_KEY
+from notification_prefs import NOTIFICATION_PREF_KEY
+from notifier_api.views import NotifierUsersViewSet
+from student.models import CourseEnrollment
+from student.tests.factories import UserFactory, CourseEnrollmentFactory
+from user_api.models import UserPreference
+from user_api.tests.factories import UserPreferenceFactory
+from util.testing import UrlResetMixin
+from xmodule.modulestore.tests.django_utils import mixed_store_config, ModuleStoreTestCase
+from xmodule.modulestore.tests.factories import CourseFactory
+
+
+@ddt.ddt
+@override_settings(EDX_API_KEY="test_api_key")
+class NotifierUsersViewSetTest(UrlResetMixin, ModuleStoreTestCase):
+    def setUp(self):
+        super(NotifierUsersViewSetTest, self).setUp()
+        self.courses = []
+        self.cohorts = []
+        self.user = UserFactory()
+        self.notification_pref = UserPreferenceFactory(
+            user=self.user,
+            key=NOTIFICATION_PREF_KEY,
+            value="notification pref test value"
+        )
+
+        self.list_view = NotifierUsersViewSet.as_view({"get": "list"})
+        self.detail_view = NotifierUsersViewSet.as_view({"get": "retrieve"})
+
+    def _set_up_course(self, is_course_cohorted, is_user_cohorted, is_moderator):
+        cohort_config = {"cohorted": True} if is_course_cohorted else {}
+        course = CourseFactory(
+            number=("TestCourse{}".format(len(self.courses))),
+            cohort_config=cohort_config
+        )
+        self.courses.append(course)
+        CourseEnrollmentFactory(user=self.user, course_id=course.id)
+        if is_user_cohorted:
+            cohort = CourseUserGroup.objects.create(
+                name="Test Cohort",
+                course_id=course.id,
+                group_type=CourseUserGroup.COHORT
+            )
+            cohort.users.add(self.user)
+            self.cohorts.append(cohort)
+        if is_moderator:
+            moderator_perm, _ = Permission.objects.get_or_create(name="see_all_cohorts")
+            moderator_role = Role.objects.create(name="Moderator", course_id=course.id)
+            moderator_role.permissions.add(moderator_perm)
+            self.user.roles.add(moderator_role)
+
+    def _assert_basic_user_info_correct(self, user, result_user):
+        self.assertEqual(result_user["id"], user.id)
+        self.assertEqual(result_user["email"], user.email)
+        self.assertEqual(result_user["name"], user.profile.name)
+
+    def test_without_api_key(self):
+        request = RequestFactory().get("dummy")
+        for view in [self.list_view, self.detail_view]:
+            response = view(request)
+            self.assertEqual(response.status_code, 403)
+
+    # Detail view tests
+
+    def _make_detail_request(self):
+        request = RequestFactory().get("dummy", HTTP_X_EDX_API_KEY=settings.EDX_API_KEY)
+        return self.detail_view(
+            request,
+            **{NotifierUsersViewSet.lookup_field: str(self.user.id)}
+        )
+
+    def _get_detail(self):
+        response = self._make_detail_request()
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(
+            set(response.data.keys()),
+            {"id", "email", "name", "preferences", "course_info"}
+        )
+        return response.data
+
+    def test_detail_invalid_user(self):
+        UserPreference.objects.all().delete()
+        response = self._make_detail_request()
+        self.assertEqual(response.status_code, 404)
+
+    def test_basic_user_info(self):
+        result = self._get_detail()
+        self._assert_basic_user_info_correct(self.user, result)
+
+    def test_course_info(self):
+        expected_course_info = {}
+        for is_course_cohorted, is_user_cohorted, is_moderator in (
+                itertools.product([True, False], [True, False], [True, False])
+        ):
+            self._set_up_course(is_course_cohorted, is_user_cohorted, is_moderator)
+            expected_course_info[unicode(self.courses[-1].id)] = {
+                "cohort_id": self.cohorts[-1].id if is_user_cohorted else None,
+                "see_all_cohorts": is_moderator or not is_course_cohorted
+            }
+        result = self._get_detail()
+        self.assertEqual(result["course_info"], expected_course_info)
+
+    def test_course_info_unenrolled(self):
+        self._set_up_course(False, False, False)
+        course_id = self.courses[0].id
+        CourseEnrollment.unenroll(self.user, course_id)
+        result = self._get_detail()
+        self.assertNotIn(unicode(course_id), result["course_info"])
+
+    def test_course_info_no_enrollments(self):
+        result = self._get_detail()
+        self.assertEqual(result["course_info"], {})
+
+    def test_preferences(self):
+        lang_pref = UserPreferenceFactory(
+            user=self.user,
+            key=LANGUAGE_KEY,
+            value="language pref test value"
+        )
+        UserPreferenceFactory(user=self.user, key="non_included_key")
+        result = self._get_detail()
+        self.assertEqual(
+            result["preferences"],
+            {
+                NOTIFICATION_PREF_KEY: self.notification_pref.value,
+                LANGUAGE_KEY: lang_pref.value,
+            }
+        )
+
+    # List view tests
+
+    def _make_list_request(self, page, page_size):
+        request = RequestFactory().get(
+            "dummy",
+            {"page": page, "page_size": page_size},
+            HTTP_X_EDX_API_KEY=settings.EDX_API_KEY
+        )
+        return self.list_view(request)
+
+    def _get_list(self, page=1, page_size=None):
+        response = self._make_list_request(page, page_size)
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(
+            set(response.data.keys()),
+            {"count", "next", "previous", "results"}
+        )
+        return response.data["results"]
+
+    def test_no_users(self):
+        UserPreference.objects.all().delete()
+        results = self._get_list()
+        self.assertEqual(len(results), 0)
+
+    def test_multiple_users(self):
+        other_user = UserFactory()
+        other_notification_pref = UserPreferenceFactory(
+            user=other_user,
+            key=NOTIFICATION_PREF_KEY,
+            value="other value"
+        )
+        self._set_up_course(is_course_cohorted=True, is_user_cohorted=True, is_moderator=False)
+        self._set_up_course(is_course_cohorted=False, is_user_cohorted=False, is_moderator=False)
+        # Users have different sets of enrollments
+        CourseEnrollmentFactory(user=other_user, course_id=self.courses[0].id)
+
+        result_map = {result["id"]: result for result in self._get_list()}
+        self.assertEqual(set(result_map.keys()), {self.user.id, other_user.id})
+        for user in [self.user, other_user]:
+            self._assert_basic_user_info_correct(user, result_map[user.id])
+        self.assertEqual(
+            result_map[self.user.id]["preferences"],
+            {NOTIFICATION_PREF_KEY: self.notification_pref.value}
+        )
+        self.assertEqual(
+            result_map[other_user.id]["preferences"],
+            {NOTIFICATION_PREF_KEY: other_notification_pref.value}
+        )
+        self.assertEqual(
+            result_map[self.user.id]["course_info"],
+            {
+                unicode(self.courses[0].id): {
+                    "cohort_id": self.cohorts[0].id,
+                    "see_all_cohorts": False,
+                },
+                unicode(self.courses[1].id): {
+                    "cohort_id": None,
+                    "see_all_cohorts": True,
+                },
+            }
+        )
+        self.assertEqual(
+            result_map[other_user.id]["course_info"],
+            {
+                unicode(self.courses[0].id): {
+                    "cohort_id": None,
+                    "see_all_cohorts": False,
+                },
+            }
+        )
+
+    @ddt.data(
+        3,  # Factor of num of results
+        5,  # Non-factor of num of results
+        12,  # Num of results
+        15  # More than num of results
+    )
+    def test_pagination(self, page_size):
+        num_users = 12
+        users = [self.user]
+        while len(users) < num_users:
+            new_user = UserFactory()
+            users.append(new_user)
+            UserPreferenceFactory(user=new_user, key=NOTIFICATION_PREF_KEY)
+
+        num_pages = (num_users - 1) / page_size + 1
+        result_list = []
+        for i in range(1, num_pages + 1):
+            result_list.extend(self._get_list(page=i, page_size=page_size))
+        result_map = {result["id"]: result for result in result_list}
+
+        self.assertEqual(len(result_list), num_users)
+        for user in users:
+            self._assert_basic_user_info_correct(user, result_map[user.id])
+        self.assertEqual(
+            self._make_list_request(page=(num_pages + 1), page_size=page_size).status_code,
+            404
+        )
+
+    def test_db_access(self):
+        for _ in range(10):
+            new_user = UserFactory()
+            UserPreferenceFactory(user=new_user, key=NOTIFICATION_PREF_KEY)
+
+        # The number of queries is one for the users plus one for each prefetch
+        # in NotifierUsersViewSet (roles__permissions does one for each table).
+        with self.assertNumQueries(6):
+            self._get_list()

lms/djangoapps/notifier_api/urls.py

+from django.conf.urls import include, patterns, url
+from rest_framework import routers
+
+from notifier_api.views import NotifierUsersViewSet
+
+
+notifier_api_router = routers.DefaultRouter()
+notifier_api_router.register(r'users', NotifierUsersViewSet, base_name="notifier_users")
+urlpatterns = patterns(
+    '',
+    url(r'^v1/', include(notifier_api_router.urls)),
+)

lms/djangoapps/notifier_api/views.py

+from django.contrib.auth.models import User
+from rest_framework.viewsets import ReadOnlyModelViewSet
+
+from notification_prefs import NOTIFICATION_PREF_KEY
+from notifier_api.serializers import NotifierUserSerializer
+from user_api.views import ApiKeyHeaderPermission
+
+
+class NotifierUsersViewSet(ReadOnlyModelViewSet):
+    """
+    An endpoint that the notifier can use to retrieve users who have enabled
+    daily forum digests, including all information that the notifier needs about
+    such users.
+    """
+    permission_classes = (ApiKeyHeaderPermission,)
+    serializer_class = NotifierUserSerializer
+    paginate_by = 10
+    paginate_by_param = "page_size"
+
+    # See NotifierUserSerializer for notes about related tables
+    queryset = User.objects.filter(
+        preferences__key=NOTIFICATION_PREF_KEY
+    ).select_related(
+        "profile"
+    ).prefetch_related(
+        "preferences",
+        "courseenrollment_set",
+        "course_groups",
+        "roles__permissions"
+    )

lms/envs/common.py

@@ -1417,6 +1417,8 @@ INSTALLED_APPS = (
     # Notification preferences setting
     'notification_prefs',
 
+    'notifier_api',
+
     # Different Course Modes
     'course_modes',
 

lms/urls.py

@@ -62,6 +62,8 @@ urlpatterns = ('',  # nopep8
 
     url(r'^user_api/', include('user_api.urls')),
 
+    url(r'^notifier_api/', include('notifier_api.urls')),
+
     url(r'^lang_pref/', include('lang_pref.urls')),
 
     url(r'^i18n/', include('django.conf.urls.i18n')),