Allow displaying videos without transcripts

cms/envs/common.py

@@ -247,6 +247,11 @@ FEATURES = {
     # Show the language selector in the header
     'SHOW_HEADER_LANGUAGE_SELECTOR': False,
 
+    # At edX it's safe to assume that English transcripts are always available
+    # This is not the case for all installations.
+    # The default value in {lms,cms}/envs/common.py and xmodule/tests/test_video.py should be consistent.
+    'FALLBACK_TO_ENGLISH_TRANSCRIPTS': True,
+
     # Set this to False to facilitate cleaning up invalid xml from your modulestore.
     'ENABLE_XBLOCK_XML_VALIDATION': True,
 

common/lib/xmodule/xmodule/tests/test_video.py

@@ -792,67 +792,44 @@ class VideoExportTestCase(VideoDescriptorTestBase):
 
 
 @ddt.ddt
+@patch.object(settings, 'YOUTUBE', create=True, new={
+    # YouTube JavaScript API
+    'API': 'www.youtube.com/iframe_api',
+
+    # URL to get YouTube metadata
+    'METADATA_URL': 'www.googleapis.com/youtube/v3/videos/',
+
+    # Current youtube api for requesting transcripts.
+    # For example: http://video.google.com/timedtext?lang=en&v=j_jEn79vS3g.
+    'TEXT_API': {
+        'url': 'video.google.com/timedtext',
+        'params': {
+            'lang': 'en',
+            'v': 'set_youtube_id_of_11_symbols_here',
+        },
+    },
+})
+@patch.object(settings, 'CONTENTSTORE', create=True, new={
+    'ENGINE': 'xmodule.contentstore.mongo.MongoContentStore',
+    'DOC_STORE_CONFIG': {
+        'host': 'edx.devstack.mongo' if 'BOK_CHOY_HOSTNAME' in os.environ else 'localhost',
+        'db': 'test_xcontent_%s' % uuid4().hex,
+    },
+    # allow for additional options that can be keyed on a name, e.g. 'trashcan'
+    'ADDITIONAL_OPTIONS': {
+        'trashcan': {
+            'bucket': 'trash_fs'
+        }
+    }
+})
+@patch.object(settings, 'FEATURES', create=True, new={
+    # The default value in {lms,cms}/envs/common.py and xmodule/tests/test_video.py should be consistent.
+    'FALLBACK_TO_ENGLISH_TRANSCRIPTS': True,
+})
 class VideoDescriptorIndexingTestCase(unittest.TestCase):
     """
     Make sure that VideoDescriptor can format data for indexing as expected.
     """
-    def setUp(self):
-        """
-        Overrides YOUTUBE and CONTENTSTORE settings
-        """
-        super(VideoDescriptorIndexingTestCase, self).setUp()
-        self.youtube_setting = getattr(settings, "YOUTUBE", None)
-        self.contentstore_setting = getattr(settings, "CONTENTSTORE", None)
-        settings.YOUTUBE = {
-            # YouTube JavaScript API
-            'API': 'www.youtube.com/iframe_api',
-
-            # URL to get YouTube metadata
-            'METADATA_URL': 'www.googleapis.com/youtube/v3/videos/',
-
-            # Current youtube api for requesting transcripts.
-            # For example: http://video.google.com/timedtext?lang=en&v=j_jEn79vS3g.
-            'TEXT_API': {
-                'url': 'video.google.com/timedtext',
-                'params': {
-                    'lang': 'en',
-                    'v': 'set_youtube_id_of_11_symbols_here',
-                },
-            },
-        }
-
-        settings.CONTENTSTORE = {
-            'ENGINE': 'xmodule.contentstore.mongo.MongoContentStore',
-            'DOC_STORE_CONFIG': {
-                'host': 'edx.devstack.mongo' if 'BOK_CHOY_HOSTNAME' in os.environ else 'localhost',
-                'db': 'test_xcontent_%s' % uuid4().hex,
-            },
-            # allow for additional options that can be keyed on a name, e.g. 'trashcan'
-            'ADDITIONAL_OPTIONS': {
-                'trashcan': {
-                    'bucket': 'trash_fs'
-                }
-            }
-        }
-
-        self.addCleanup(self.cleanup)
-
-    def cleanup(self):
-        """
-        Returns YOUTUBE and CONTENTSTORE settings to a default value
-        """
-        if self.youtube_setting:
-            settings.YOUTUBE = self.youtube_setting
-            self.youtube_setting = None
-        else:
-            del settings.YOUTUBE
-
-        if self.contentstore_setting:
-            settings.CONTENTSTORE = self.contentstore_setting
-            self.contentstore_setting = None
-        else:
-            del settings.CONTENTSTORE
-
     def test_video_with_no_subs_index_dictionary(self):
         """
         Test index dictionary of a video module without subtitles.
@@ -993,7 +970,7 @@ class VideoDescriptorIndexingTestCase(unittest.TestCase):
         '''
 
         descriptor = instantiate_descriptor(data=xml_data_transcripts)
-        translations = descriptor.available_translations(descriptor.get_transcripts_info(), verify_assets=False)
+        translations = descriptor.available_translations(descriptor.get_transcripts_info())
         self.assertEqual(translations, ['hr', 'ge'])
 
     def test_video_with_no_transcripts_translation_retrieval(self):
@@ -1003,8 +980,14 @@ class VideoDescriptorIndexingTestCase(unittest.TestCase):
         does not throw an exception.
         """
         descriptor = instantiate_descriptor(data=None)
-        translations = descriptor.available_translations(descriptor.get_transcripts_info(), verify_assets=False)
-        self.assertEqual(translations, ['en'])
+        translations_with_fallback = descriptor.available_translations(descriptor.get_transcripts_info())
+        self.assertEqual(translations_with_fallback, ['en'])
+
+        with patch.dict(settings.FEATURES, FALLBACK_TO_ENGLISH_TRANSCRIPTS=False):
+            # Some organizations don't have English transcripts for all videos
+            # This feature makes it configurable
+            translations_no_fallback = descriptor.available_translations(descriptor.get_transcripts_info())
+            self.assertEqual(translations_no_fallback, [])
 
     @override_settings(ALL_LANGUAGES=ALL_LANGUAGES)
     def test_video_with_language_do_not_have_transcripts_translation(self):

common/lib/xmodule/xmodule/video_module/transcripts_utils.py

@@ -2,6 +2,7 @@
 Utility functions for transcripts.
 ++++++++++++++++++++++++++++++++++
 """
+from django.conf import settings
 import os
 import copy
 import json
@@ -556,7 +557,7 @@ class VideoTranscriptsMixin(object):
     This is necessary for both VideoModule and VideoDescriptor.
     """
 
-    def available_translations(self, transcripts, verify_assets=True):
+    def available_translations(self, transcripts, verify_assets=None):
         """Return a list of language codes for which we have transcripts.
 
         Args:
@@ -566,13 +567,16 @@ class VideoTranscriptsMixin(object):
                 we might do this is to avoid slamming contentstore() with queries
                 when trying to make a listing of videos and their languages.
 
-                Defaults to True.
+                Defaults to `not FALLBACK_TO_ENGLISH_TRANSCRIPTS`.
 
             transcripts (dict): A dict with all transcripts and a sub.
 
                 Defaults to False
         """
         translations = []
+        if verify_assets is None:
+            verify_assets = not settings.FEATURES.get('FALLBACK_TO_ENGLISH_TRANSCRIPTS')
+
         sub, other_langs = transcripts["sub"], transcripts["transcripts"]
 
         # If we're not verifying the assets, we just trust our field values

common/lib/xmodule/xmodule/video_module/video_handlers.py

@@ -276,7 +276,7 @@ class VideoStudentViewHandlers(object):
 
         elif dispatch.startswith('available_translations'):
 
-            available_translations = self.available_translations(transcripts)
+            available_translations = self.available_translations(transcripts, verify_assets=True)
             if available_translations:
                 response = Response(json.dumps(available_translations))
                 response.content_type = 'application/json'

common/lib/xmodule/xmodule/video_module/video_module.py

@@ -991,7 +991,7 @@ class VideoDescriptor(VideoFields, VideoTranscriptsMixin, VideoStudioViewHandler
         transcripts_info = self.get_transcripts_info()
         transcripts = {
             lang: self.runtime.handler_url(self, 'transcript', 'download', query="lang=" + lang, thirdparty=True)
-            for lang in self.available_translations(transcripts_info, verify_assets=False)
+            for lang in self.available_translations(transcripts_info)
         }
 
         return {

lms/djangoapps/mobile_api/video_outlines/serializers.py

@@ -209,7 +209,7 @@ def video_summary(video_profiles, course_id, video_descriptor, request, local_ca
 
     # Transcripts...
     transcripts_info = video_descriptor.get_transcripts_info()
-    transcript_langs = video_descriptor.available_translations(transcripts_info, verify_assets=False)
+    transcript_langs = video_descriptor.available_translations(transcripts_info)
 
     transcripts = {
         lang: reverse(

lms/djangoapps/mobile_api/video_outlines/tests.py

@@ -8,8 +8,10 @@ from collections import namedtuple
 from uuid import uuid4
 
 import ddt
+from django.conf import settings
 from edxval import api
 from milestones.tests.utils import MilestonesTestCaseMixin
+from mock import patch
 from nose.plugins.attrib import attr
 
 from mobile_api.models import MobileApiConfig
@@ -515,6 +517,16 @@ class TestVideoSummaryList(TestVideoAPITestCase, MobileAuthTestMixin, MobileCour
             'size': 111
         }
 
+        # The transcript was not entered, so it should not be found!
+        # This is the default behaviour at courses.edX.org, based on `FALLBACK_TO_ENGLISH_TRANSCRIPTS`
+        transcripts_response = self.client.get(expected_output['transcripts']['en'])
+        self.assertEqual(404, transcripts_response.status_code)
+
+        with patch.dict(settings.FEATURES, FALLBACK_TO_ENGLISH_TRANSCRIPTS=False):
+            # Other platform installations may override this setting
+            # This ensures that the server don't return empty English transcripts when there's none!
+            self.assertFalse(self.api_response().data[0]['summary'].get('transcripts'))
+
         # Testing when video_profiles='mobile_low,mobile_high,youtube'
         course_outline = self.api_response().data
         course_outline[0]['summary'].pop("id")

lms/envs/common.py

@@ -346,6 +346,11 @@ FEATURES = {
     # Show the language selector in the header
     'SHOW_HEADER_LANGUAGE_SELECTOR': False,
 
+    # At edX it's safe to assume that English transcripts are always available
+    # This is not the case for all installations.
+    # The default value in {lms,cms}/envs/common.py and xmodule/tests/test_video.py should be consistent.
+    'FALLBACK_TO_ENGLISH_TRANSCRIPTS': True,
+
     # Show the language selector in the footer
     'SHOW_FOOTER_LANGUAGE_SELECTOR': False,