Merge pull request #36 from edx/gprice/add-order-alt

Add sorting parameters to get_videos_for_ids

edxval/api.py

@@ -3,6 +3,7 @@
 """
 The internal API for VAL. This is not yet stable
 """
+from enum import Enum
 import logging
 
 from edxval.models import Video, EncodedVideo
@@ -52,6 +53,21 @@ class ValCannotCreateError(ValError):
     pass
 
 
+class VideoSortField(Enum):
+    """An enum representing sortable fields in the Video model"""
+    created = "created"
+    edx_video_id = "edx_video_id"
+    client_video_id = "client_video_id"
+    duration = "duration"
+    # status omitted because user-facing strings do not match data
+
+
+class SortDirection(Enum):
+    """An enum representing sort direction"""
+    asc = "asc"
+    desc = "desc"
+
+
 def create_video(video_data):
     """
     Called on to create Video objects in the database
@@ -234,17 +250,30 @@ def get_videos_for_course(course_id):
     return (VideoSerializer(video).data for video in videos)
 
 
-def get_videos_for_ids(edx_video_ids):
+def get_videos_for_ids(
+        edx_video_ids,
+        sort_field=None,
+        sort_dir=SortDirection.asc
+):
     """
     Returns an iterator of videos that match the given list of ids
 
     Args:
         edx_video_ids (list)
+        sort_field (VideoSortField)
+        sort_dir (SortDirection)
 
     Returns:
-        A generator expression that contains the videos found
+        A generator expression that contains the videos found, sorted by the
+        given field and direction, with ties broken by edx_video_id to ensure a
+        total order
     """
     videos = Video.objects.filter(edx_video_id__in=edx_video_ids)
+    if sort_field:
+        # Refining by edx_video_id ensures a total order
+        videos = videos.order_by(sort_field.value, "edx_video_id")
+        if sort_dir == SortDirection.desc:
+            videos = videos.reverse()
     return (VideoSerializer(video).data for video in videos)
 
 

edxval/tests/test_api.py

@@ -14,7 +14,7 @@ from ddt import ddt, data
 
 from edxval.models import Profile, Video, EncodedVideo, CourseVideo
 from edxval import api as api
-from edxval.api import ValCannotCreateError
+from edxval.api import SortDirection, ValCannotCreateError, VideoSortField
 from edxval.serializers import VideoSerializer
 from edxval.tests import constants, APIAuthTestCase
 
@@ -334,6 +334,44 @@ class GetVideosForIds(TestCase):
         videos = list(api.get_videos_for_ids([edx_video_id, edx_video_id]))
         self.assertEqual(len(videos), 1)
 
+    def test_get_videos_for_ids_sort(self):
+        fish_id = constants.VIDEO_DICT_FISH["edx_video_id"]
+        star_id = constants.VIDEO_DICT_STAR["edx_video_id"]
+        other_id = "other-video"
+        Video.objects.create(**constants.VIDEO_DICT_STAR)
+        # This is made to sort with the other videos differently by each field
+        Video.objects.create(
+            client_video_id="other video",
+            duration=555.0,
+            edx_video_id=other_id
+        )
+
+        def check_sort(sort_field, expected_ids_for_asc):
+            """
+            Assert that sorting by given field returns videos in the expected
+            order (checking both ascending and descending)
+            """
+            def check_direction(sort_dir, expected_ids):
+                """Assert that the given videos match the expected ids"""
+                actual_videos = api.get_videos_for_ids(
+                    # Make sure it's not just returning the order given
+                    list(reversed(expected_ids)),
+                    sort_field,
+                    sort_dir
+                )
+                actual_ids = [video["edx_video_id"] for video in actual_videos]
+                self.assertEqual(actual_ids, expected_ids)
+            check_direction(SortDirection.asc, expected_ids_for_asc)
+            check_direction(
+                SortDirection.desc,
+                list(reversed(expected_ids_for_asc))
+            )
+
+        check_sort(VideoSortField.client_video_id, [fish_id, star_id, other_id])
+        check_sort(VideoSortField.edx_video_id, [star_id, other_id, fish_id])
+        # Check a field with a tie
+        check_sort(VideoSortField.duration, [star_id, fish_id, other_id])
+
 
 class GetVideoInfoTestWithHttpCalls(APIAuthTestCase):
     """

requirements.txt

 django>=1.4,<1.5
 djangorestframework<2.4
+enum34==1.0.4
 South==0.7.6
 -e git+https://github.com/edx/django-oauth2-provider.git@0.2.7-fork-edx-1#egg=django-oauth2-provider