Added Current Grade Rest API

lms/djangoapps/grades/api/tests/test_views.py

+"""
+Tests for the views
+"""
+from datetime import datetime
+
+import ddt
+from django.core.urlresolvers import reverse
+from mock import patch
+from opaque_keys import InvalidKeyError
+from pytz import UTC
+from rest_framework import status
+from rest_framework.test import APITestCase
+
+from lms.djangoapps.grades.tests.utils import mock_get_score
+from student.tests.factories import CourseEnrollmentFactory, UserFactory
+from xmodule.modulestore.tests.factories import CourseFactory, ItemFactory
+from xmodule.modulestore.tests.django_utils import SharedModuleStoreTestCase, TEST_DATA_SPLIT_MODULESTORE
+
+
+@ddt.ddt
+class CurrentGradeViewTest(SharedModuleStoreTestCase, APITestCase):
+    """
+    Tests for the Current Grade View
+
+    The following tests assume that the grading policy is the edX default one:
+    {
+        "GRADER": [
+            {
+                "drop_count": 2,
+                "min_count": 12,
+                "short_label": "HW",
+                "type": "Homework",
+                "weight": 0.15
+            },
+            {
+                "drop_count": 2,
+                "min_count": 12,
+                "type": "Lab",
+                "weight": 0.15
+            },
+            {
+                "drop_count": 0,
+                "min_count": 1,
+                "short_label": "Midterm",
+                "type": "Midterm Exam",
+                "weight": 0.3
+            },
+            {
+                "drop_count": 0,
+                "min_count": 1,
+                "short_label": "Final",
+                "type": "Final Exam",
+                "weight": 0.4
+            }
+        ],
+        "GRADE_CUTOFFS": {
+            "Pass": 0.5
+        }
+    }
+    """
+    MODULESTORE = TEST_DATA_SPLIT_MODULESTORE
+
+    @classmethod
+    def setUpClass(cls):
+        super(CurrentGradeViewTest, cls).setUpClass()
+
+        cls.course = CourseFactory.create(display_name='test course', run="Testing_course")
+
+        chapter = ItemFactory.create(
+            category='chapter',
+            parent_location=cls.course.location,
+            display_name="Chapter 1",
+        )
+        # create a problem for each type and minimum count needed by the grading policy
+        # A section is not considered if the student answers less than "min_count" problems
+        for grading_type, min_count in (("Homework", 12), ("Lab", 12), ("Midterm Exam", 1), ("Final Exam", 1)):
+            for num in xrange(min_count):
+                section = ItemFactory.create(
+                    category='sequential',
+                    parent_location=chapter.location,
+                    due=datetime(2013, 9, 18, 11, 30, 00),
+                    display_name='Sequential {} {}'.format(grading_type, num),
+                    format=grading_type,
+                    graded=True,
+                )
+                vertical = ItemFactory.create(
+                    category='vertical',
+                    parent_location=section.location,
+                    display_name='Vertical {} {}'.format(grading_type, num),
+                )
+                ItemFactory.create(
+                    category='problem',
+                    parent_location=vertical.location,
+                    display_name='Problem {} {}'.format(grading_type, num),
+                )
+
+        cls.course_key = cls.course.id
+
+        cls.password = 'test'
+        cls.student = UserFactory(username='dummy', password=cls.password)
+        cls.other_student = UserFactory(username='foo', password=cls.password)
+        cls.other_user = UserFactory(username='bar', password=cls.password)
+        date = datetime(2013, 1, 22, tzinfo=UTC)
+        for user in (cls.student, cls.other_student, ):
+            CourseEnrollmentFactory(
+                course_id=cls.course.id,
+                user=user,
+                created=date,
+            )
+
+        cls.namespaced_url = 'grades_api:user_grade_detail'
+
+    def setUp(self):
+        super(CurrentGradeViewTest, self).setUp()
+        self.client.login(username=self.student.username, password=self.password)
+
+    def get_url(self, username):
+        """
+        Helper function to create the url
+        """
+        base_url = reverse(
+            self.namespaced_url,
+            kwargs={
+                'course_id': self.course_key,
+            }
+        )
+        return "{0}?username={1}".format(base_url, username)
+
+    def test_anonymous(self):
+        """
+        Test that an anonymous user cannot access the API and an error is received.
+        """
+        self.client.logout()
+        resp = self.client.get(self.get_url(self.student.username))
+        self.assertEqual(resp.status_code, status.HTTP_401_UNAUTHORIZED)
+
+    def test_self_get_grade(self):
+        """
+        Test that a user can successfully request her own grade.
+        """
+        resp = self.client.get(self.get_url(self.student.username))
+        self.assertEqual(resp.status_code, status.HTTP_200_OK)
+
+    def test_nonexistent_user(self):
+        """
+        Test that a request for a nonexistent username returns an error.
+        """
+        resp = self.client.get(self.get_url('IDoNotExist'))
+        self.assertEqual(resp.status_code, status.HTTP_404_NOT_FOUND)
+        self.assertIn('error_code', resp.data)  # pylint: disable=no-member
+        self.assertEqual(resp.data['error_code'], 'user_mismatch')  # pylint: disable=no-member
+
+    def test_other_get_grade(self):
+        """
+        Test that if a user requests the grade for another user, she receives an error.
+        """
+        self.client.logout()
+        self.client.login(username=self.other_student.username, password=self.password)
+        resp = self.client.get(self.get_url(self.student.username))
+        self.assertEqual(resp.status_code, status.HTTP_404_NOT_FOUND)
+        self.assertIn('error_code', resp.data)  # pylint: disable=no-member
+        self.assertEqual(resp.data['error_code'], 'user_mismatch')  # pylint: disable=no-member
+
+    def test_self_get_grade_not_enrolled(self):
+        """
+        Test that a user receives an error if she requests
+        her own grade in a course where she is not enrolled.
+        """
+        # a user not enrolled in the course cannot request her grade
+        self.client.logout()
+        self.client.login(username=self.other_user.username, password=self.password)
+        resp = self.client.get(self.get_url(self.other_user.username))
+        self.assertEqual(resp.status_code, status.HTTP_404_NOT_FOUND)
+        self.assertIn('error_code', resp.data)  # pylint: disable=no-member
+        self.assertEqual(
+            resp.data['error_code'],  # pylint: disable=no-member
+            'user_or_course_does_not_exist'
+        )
+
+    def test_wrong_course_key(self):
+        """
+        Test that a request for an invalid course key returns an error.
+        """
+        def mock_from_string(*args, **kwargs):  # pylint: disable=unused-argument
+            """Mocked function to always raise an exception"""
+            raise InvalidKeyError('foo', 'bar')
+        with patch('opaque_keys.edx.keys.CourseKey.from_string', side_effect=mock_from_string):
+            resp = self.client.get(self.get_url(self.student.username))
+        self.assertEqual(resp.status_code, status.HTTP_404_NOT_FOUND)
+        self.assertIn('error_code', resp.data)  # pylint: disable=no-member
+        self.assertEqual(
+            resp.data['error_code'],  # pylint: disable=no-member
+            'invalid_course_key'
+        )
+
+    def test_course_does_not_exist(self):
+        """
+        Test that requesting a valid, nonexistent course key returns an error as expected.
+        """
+        base_url = reverse(
+            self.namespaced_url,
+            kwargs={
+                'course_id': 'course-v1:MITx+8.MechCX+2014_T1',
+            }
+        )
+        url = "{0}?username={1}".format(base_url, self.student.username)
+        resp = self.client.get(url)
+        self.assertEqual(resp.status_code, status.HTTP_404_NOT_FOUND)
+        self.assertIn('error_code', resp.data)  # pylint: disable=no-member
+        self.assertEqual(
+            resp.data['error_code'],  # pylint: disable=no-member
+            'user_or_course_does_not_exist'
+        )
+
+    def test_no_grade(self):
+        """
+        Test the grade for a user who has not answered any test.
+        """
+        resp = self.client.get(self.get_url(self.student.username))
+        self.assertEqual(resp.status_code, status.HTTP_200_OK)
+        expected_data = [{
+            'username': self.student.username,
+            'letter_grade': None,
+            'percent': 0.0,
+            'course_key': str(self.course_key),
+            'passed': False
+        }]
+        self.assertEqual(resp.data, expected_data)  # pylint: disable=no-member
+
+    @ddt.data(
+        ((2, 5), {'letter_grade': None, 'percent': 0.4, 'passed': False}),
+        ((5, 5), {'letter_grade': 'Pass', 'percent': 1, 'passed': True}),
+    )
+    @ddt.unpack
+    def test_grade(self, grade, result):
+        """
+        Test that the user gets her grade in case she answered tests with an insufficient score.
+        """
+        with mock_get_score(*grade):
+            resp = self.client.get(self.get_url(self.student.username))
+        self.assertEqual(resp.status_code, status.HTTP_200_OK)
+        expected_data = {
+            'username': self.student.username,
+            'course_key': str(self.course_key),
+        }
+        expected_data.update(result)
+        self.assertEqual(resp.data, [expected_data])  # pylint: disable=no-member

lms/djangoapps/grades/api/urls.py

+""" Grades API URLs. """
+from django.conf import settings
+from django.conf.urls import (
+    patterns,
+    url,
+)
+
+from lms.djangoapps.grades.api import views
+
+urlpatterns = patterns(
+    '',
+    url(
+        r'^v0/course_grade/{course_id}/users/$'.format(
+            course_id=settings.COURSE_ID_PATTERN
+        ),
+        views.UserGradeView.as_view(), name='user_grade_detail'
+    ),
+)

lms/djangoapps/grades/api/views.py

+""" API v0 views. """
+import logging
+
+from django.http import Http404
+from opaque_keys import InvalidKeyError
+from opaque_keys.edx.keys import CourseKey
+from rest_framework import status
+from rest_framework.authentication import SessionAuthentication
+from rest_framework.generics import GenericAPIView
+from rest_framework.permissions import IsAuthenticated
+from rest_framework.response import Response
+
+from lms.djangoapps.ccx.utils import prep_course_for_grading
+from lms.djangoapps.courseware import courses
+from lms.djangoapps.grades.new.course_grade import CourseGradeFactory
+from openedx.core.lib.api.authentication import OAuth2AuthenticationAllowInactiveUser
+from openedx.core.lib.api.view_utils import DeveloperErrorViewMixin
+
+log = logging.getLogger(__name__)
+
+
+class UserGradeView(DeveloperErrorViewMixin, GenericAPIView):
+    """
+    **Use Case**
+
+        * Get the current course grades for users in a course.
+          Currently, getting the grade for only an individual user is supported.
+
+    **Example Request**
+
+        GET /api/grades/v0/course_grade/{course_id}/users/?username={username}
+
+    **GET Parameters**
+
+        A GET request must include the following parameters.
+
+        * course_id: A string representation of a Course ID.
+        * username: A string representation of a user's username.
+
+    **GET Response Values**
+
+        If the request for information about the course grade
+        is successful, an HTTP 200 "OK" response is returned.
+
+        The HTTP 200 response has the following values.
+
+        * username: A string representation of a user's username passed in the request.
+
+        * course_id: A string representation of a Course ID.
+
+        * passed: Boolean representing whether the course has been
+                  passed according the course's grading policy.
+
+        * percent: A float representing the overall grade for the course
+
+        * letter_grade: A letter grade as defined in grading_policy (e.g. 'A' 'B' 'C' for 6.002x) or None
+
+
+    **Example GET Response**
+
+        [{
+            "username": "bob",
+            "course_key": "edX/DemoX/Demo_Course",
+            "passed": false,
+            "percent": 0.03,
+            "letter_grade": None,
+        }]
+
+    """
+    authentication_classes = (
+        OAuth2AuthenticationAllowInactiveUser,
+        SessionAuthentication,
+    )
+    permission_classes = (IsAuthenticated, )
+
+    def get(self, request, course_id):
+        """
+        Gets a course progress status.
+
+        Args:
+            request (Request): Django request object.
+            course_id (string): URI element specifying the course location.
+
+        Return:
+            A JSON serialized representation of the requesting user's current grade status.
+        """
+        username = request.GET.get('username')
+
+        # only the student can access her own grade status info
+        if request.user.username != username:
+            log.info(
+                'User %s tried to access the grade for user %s.',
+                request.user.username,
+                username
+            )
+            return self.make_error_response(
+                status_code=status.HTTP_404_NOT_FOUND,
+                developer_message='The user requested does not match the logged in user.',
+                error_code='user_mismatch'
+            )
+
+        # build the course key
+        try:
+            course_key = CourseKey.from_string(course_id)
+        except InvalidKeyError:
+            return self.make_error_response(
+                status_code=status.HTTP_404_NOT_FOUND,
+                developer_message='The provided course key cannot be parsed.',
+                error_code='invalid_course_key'
+            )
+        # load the course
+        try:
+            course = courses.get_course_with_access(
+                request.user,
+                'load',
+                course_key,
+                depth=None,
+                check_if_enrolled=True
+            )
+        except Http404:
+            log.info('Course with ID "%s" not found', course_id)
+            return self.make_error_response(
+                status_code=status.HTTP_404_NOT_FOUND,
+                developer_message='The user, the course or both do not exist.',
+                error_code='user_or_course_does_not_exist'
+            )
+        prep_course_for_grading(course, request)
+        course_grade = CourseGradeFactory(request.user).create(course)
+        if not course_grade.has_access_to_course:
+            # This means the student didn't have access to the course
+            log.info('User %s not allowed to access grade for course %s', request.user.username, username)
+            return self.make_error_response(
+                status_code=status.HTTP_403_FORBIDDEN,
+                developer_message='The user does not have access to the course.',
+                error_code='user_does_not_have_access_to_course'
+            )
+
+        return Response([{
+            'username': username,
+            'course_key': course_id,
+            'passed': course_grade.passed,
+            'percent': course_grade.percent,
+            'letter_grade': course_grade.letter_grade,
+        }])

lms/djangoapps/grades/new/course_grade.py

@@ -52,6 +52,18 @@ class CourseGrade(object):
                 locations_to_weighted_scores.update(subsection_grade.locations_to_weighted_scores)
         return locations_to_weighted_scores
 
+    @lazy
+    def grade_value(self):
+        """
+        Helper function to extract the grade value as calculated by the course's grader.
+        """
+        # Grading policy might be overriden by a CCX, need to reset it
+        self.course.set_grading_policy(self.course.grading_policy)
+        return self.course.grader.grade(
+            self.subsection_grade_totals_by_format,
+            generate_random_scores=settings.GENERATE_PROFILE_SCORES
+        )
+
     @property
     def has_access_to_course(self):
         """
@@ -60,22 +72,41 @@ class CourseGrade(object):
         """
         return len(self.course_structure) > 0
 
-    @lazy
+    @property
+    def percent(self):
+        """
+        Returns a rounded percent from the overall grade.
+        """
+        return round(self.grade_value['percent'] * 100 + 0.05) / 100
+
+    @property
+    def letter_grade(self):
+        """
+        Returns a letter representing the grade.
+        """
+        return self._compute_letter_grade(self.percent)
+
+    @property
+    def passed(self):
+        """
+        Check user's course passing status. Return True if passed.
+        """
+        nonzero_cutoffs = [cutoff for cutoff in self.course.grade_cutoffs.values() if cutoff > 0]
+        success_cutoff = min(nonzero_cutoffs) if nonzero_cutoffs else None
+        return success_cutoff and self.percent >= success_cutoff
+
+    @property
     def summary(self):
         """
         Returns the grade summary as calculated by the course's grader.
         """
-        # Grading policy might be overriden by a CCX, need to reset it
-        self.course.set_grading_policy(self.course.grading_policy)
-        grade_summary = self.course.grader.grade(
-            self.subsection_grade_totals_by_format,
-            generate_random_scores=settings.GENERATE_PROFILE_SCORES
-        )
+        grade_summary = self.grade_value
 
         # We round the grade here, to make sure that the grade is a whole percentage and
         # doesn't get displayed differently than it gets grades
-        grade_summary['percent'] = round(grade_summary['percent'] * 100 + 0.05) / 100
-        grade_summary['grade'] = self._compute_letter_grade(grade_summary['percent'])
+        grade_summary['percent'] = self.percent
+        grade_summary['grade'] = self.letter_grade
+
         grade_summary['totaled_scores'] = self.subsection_grade_totals_by_format
         grade_summary['raw_scores'] = list(self.locations_to_weighted_scores.itervalues())
 

lms/urls.py

@@ -492,6 +492,7 @@ urlpatterns += (
         name='courseware_position',
     ),
 
+    # progress page
     url(
         r'^courses/{}/progress$'.format(
             settings.COURSE_ID_PATTERN,
@@ -499,6 +500,7 @@ urlpatterns += (
         'courseware.views.views.progress',
         name='progress',
     ),
+
     # Takes optional student_id for instructor use--shows profile as that student sees it.
     url(
         r'^courses/{}/progress/(?P<student_id>[^/]*)/$'.format(
@@ -508,6 +510,13 @@ urlpatterns += (
         name='student_progress',
     ),
 
+    # rest api for grades
+    url(
+        r'^api/grades/',
+        include('lms.djangoapps.grades.api.urls', namespace='grades_api')
+    ),
+
+
     # For the instructor
     url(
         r'^courses/{}/instructor$'.format(

openedx/core/lib/api/view_utils.py

@@ -32,11 +32,14 @@ class DeveloperErrorViewMixin(object):
     (auth failure, method not allowed, etc.) by generating an error response
     conforming to our API conventions with a developer message.
     """
-    def make_error_response(self, status_code, developer_message):
+    def make_error_response(self, status_code, developer_message, error_code=None):
         """
         Build an error response with the given status code and developer_message
         """
-        return Response({"developer_message": developer_message}, status=status_code)
+        error_data = {"developer_message": developer_message}
+        if error_code is not None:
+            error_data['error_code'] = error_code
+        return Response(error_data, status=status_code)
 
     def make_validation_error_response(self, validation_error):
         """