BLD-837: Fix download transcript behavior.

cms/djangoapps/contentstore/features/video-editor.py

@@ -45,7 +45,7 @@ def correct_video_settings(_step):
         ['HTML5 Transcript', '', False],
         ['Show Transcript', 'True', False],
         ['Start Time', '00:00:00', False],
-        # ['Transcript Download Allowed', 'False', False],
+        ['Transcript Download Allowed', 'False', False],
         ['Video Download Allowed', 'False', False],
         ['Video Sources', '', False],
         ['Youtube ID', 'OEoXaMPEzfM', False],

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

@@ -277,6 +277,36 @@ class VideoDescriptorImportTestCase(unittest.TestCase):
             'data': ''
         })
 
+    def test_from_xml_missing_download_track(self):
+        """
+        Ensure that attributes have the right values if they aren't
+        explicitly set in XML.
+        """
+        module_system = DummySystem(load_error_modules=True)
+        xml_data = '''
+            <video display_name="Test Video"
+                   youtube="1.0:p2Q6BrNhdh8,1.25:1EeWXzPdhSA"
+                   show_captions="true">
+              <source src="http://www.example.com/source.mp4"/>
+              <track src="http://www.example.com/track"/>
+            </video>
+        '''
+        output = VideoDescriptor.from_xml(xml_data, module_system, Mock())
+        self.assert_attributes_equal(output, {
+            'youtube_id_0_75': '',
+            'youtube_id_1_0': 'p2Q6BrNhdh8',
+            'youtube_id_1_25': '1EeWXzPdhSA',
+            'youtube_id_1_5': '',
+            'show_captions': True,
+            'start_time': datetime.timedelta(seconds=0.0),
+            'end_time': datetime.timedelta(seconds=0.0),
+            'track': 'http://www.example.com/track',
+            'download_track': True,
+            'download_video': True,
+            'html5_sources': ['http://www.example.com/source.mp4'],
+            'data': ''
+        })
+
     def test_from_xml_no_attributes(self):
         """
         Make sure settings are correct if none are explicitly set in XML.

common/lib/xmodule/xmodule/video_module.py

@@ -13,12 +13,12 @@ in XML.
 import json
 import logging
 
-from HTMLParser import HTMLParser
 from lxml import etree
 from pkg_resources import resource_string
 import datetime
 import copy
 from webob import Response
+from pysrt import SubRipTime, SubRipItem
 
 from django.conf import settings
 
@@ -116,8 +116,6 @@ class VideoFields(object):
         display_name="Video Sources",
         scope=Scope.settings,
     )
-    # `track` is deprecated field and should not be used in future.
-    # `download_track` is used instead.
     track = String(
         help="The external URL to download the timed transcript track. This appears as a link beneath the video.",
         display_name="Download Transcript",
@@ -215,14 +213,11 @@ class VideoModule(VideoFields, XModule):
             elif self.html5_sources:
                 sources['main'] = self.html5_sources[0]
 
-        # Commented due to the reason described in BLD-811.
-        # if self.download_track:
-        #     if self.track:
-        #         track_url = self.track
-        #     elif self.sub:
-        #         track_url = self.runtime.handler_url(self, 'download_transcript')
-
-        track_url = self.track
+        if self.download_track:
+            if self.track:
+                track_url = self.track
+            elif self.sub:
+                track_url = self.runtime.handler_url(self, 'download_transcript')
 
         return self.system.render_template('video.html', {
             'ajax_url': self.system.ajax_url + '/save_user_state',
@@ -250,14 +245,14 @@ class VideoModule(VideoFields, XModule):
 
     def get_transcript(self, subs_id):
         '''
-        Returns transcript without timecodes.
+        Returns transcript in *.srt format.
 
         Args:
             `subs_id`: str, subtitles id
 
         Raises:
             - NotFoundError if cannot find transcript file in storage.
-            - ValueError if transcript file is incorrect JSON.
+            - ValueError if transcript file is empty or incorrect JSON.
             - KeyError if transcript file has incorrect format.
         '''
 
@@ -265,11 +260,13 @@ class VideoModule(VideoFields, XModule):
         content_location = StaticContent.compute_location(
             self.location.org, self.location.course, filename
         )
+        sjson_transcripts = contentstore().find(content_location)
+        str_subs = _generate_srt_from_sjson(json.loads(sjson_transcripts.data), speed=1.0)
+        if not str_subs:
+            log.debug('generate_srt_from_sjson produces no subtitles')
+            raise ValueError
 
-        data = contentstore().find(content_location).data
-        text = json.loads(data)['text']
-
-        return HTMLParser().unescape("\n".join(text))
+        return str_subs
 
 
     @XBlock.handler
@@ -289,9 +286,9 @@ class VideoModule(VideoFields, XModule):
         response = Response(
             subs,
             headerlist=[
-                ('Content-Disposition', 'attachment; filename="{0}.txt"'.format(self.sub)),
+                ('Content-Disposition', 'attachment; filename="{0}.srt"'.format(self.sub)),
             ])
-        response.content_type="text/plain; charset=utf-8"
+        response.content_type="application/x-subrip"
 
         return response
 
@@ -317,15 +314,6 @@ class VideoDescriptor(VideoFields, TabsEditingDescriptor, EmptyDataRawDescriptor
         '''
         Mostly handles backward compatibility issues.
 
-        Track was deprecated field, but functionality was reverted,
-        this is commented out because might be used in future.
-        ###
-        `track` is deprecated field.
-        If `track` field exists show `track` field on front-end as not-editable
-        but clearable. Dropdown `download_track` is a new field and it has value
-        True.
-        ###
-
         `source` is deprecated field.
         a) If `source` exists and `source` is not `html5_sources`: show `source`
             field on front-end as not-editable but clearable. Dropdown is a new
@@ -344,14 +332,6 @@ class VideoDescriptor(VideoFields, TabsEditingDescriptor, EmptyDataRawDescriptor
 
         editable_fields = self.editable_metadata_fields
 
-        # Commented due to the reason described in BLD-811.
-        # self.track_visible = False
-        # if self.track:
-        #     self.track_visible = True
-        #     download_track = editable_fields['download_track']
-        #     if not download_track['explicitly_set']:
-        #         self.download_track = True
-
         self.source_visible = False
         if self.source:
             # If `source` field value exist in the `html5_sources` field values,
@@ -369,16 +349,6 @@ class VideoDescriptor(VideoFields, TabsEditingDescriptor, EmptyDataRawDescriptor
     def editable_metadata_fields(self):
         editable_fields = super(VideoDescriptor, self).editable_metadata_fields
 
-        # Commented due to the reason described in BLD-811.
-        # if hasattr(self, 'track_visible'):
-        #     if self.track_visible:
-        #         editable_fields['track']['non_editable'] = True
-        #     else:
-        #         editable_fields.pop('track')
-
-        if 'download_track' in editable_fields:
-            editable_fields.pop('download_track')
-
         if hasattr(self, 'source_visible'):
             if self.source_visible:
                 editable_fields['source']['non_editable'] = True
@@ -577,10 +547,17 @@ class VideoDescriptor(VideoFields, TabsEditingDescriptor, EmptyDataRawDescriptor
                     value = deserialize_field(cls.fields[attr], value)
                 field_data[attr] = value
 
-        # Add `source` for backwards compatibility if xml doesn't  have `download_video`.
+        # For backwards compatibility: Add `source` if XML doesn't have `download_video`
+        # attribute.
         if 'download_video' not in field_data and sources:
             field_data['source'] = field_data['html5_sources'][0]
 
+        # For backwards compatibility: if XML doesn't have `download_track` attribute,
+        # it means that it is an old format. So, if `track` has some value,
+        # `download_track` needs to have value `True`.
+        if 'download_track' not in field_data and track is not None:
+            field_data['download_track'] = True
+
         return field_data
 
 
@@ -602,3 +579,60 @@ def _create_youtube_string(module):
                      for pair
                      in zip(youtube_speeds, youtube_ids)
                      if pair[1]])
+
+
+def _generate_subs(speed, source_speed, source_subs):
+    """
+    Generate transcripts from one speed to another speed.
+
+    Args:
+    `speed`: float, for this speed subtitles will be generated,
+    `source_speed`: float, speed of source_subs
+    `soource_subs`: dict, existing subtitles for speed `source_speed`.
+
+    Returns:
+    `subs`: dict, actual subtitles.
+    """
+    if speed == source_speed:
+        return source_subs
+
+    coefficient = 1.0 * speed / source_speed
+    subs = {
+        'start': [
+            int(round(timestamp * coefficient)) for
+            timestamp in source_subs['start']
+        ],
+        'end': [
+            int(round(timestamp * coefficient)) for
+            timestamp in source_subs['end']
+        ],
+        'text': source_subs['text']}
+    return subs
+
+
+def _generate_srt_from_sjson(sjson_subs, speed):
+    """Generate transcripts with speed = 1.0 from sjson to SubRip (*.srt).
+
+    :param sjson_subs: "sjson" subs.
+    :param speed: speed of `sjson_subs`.
+    :returns: "srt" subs.
+    """
+
+    output = ''
+
+    equal_len = len(sjson_subs['start']) == len(sjson_subs['end']) == len(sjson_subs['text'])
+    if not equal_len:
+        return output
+
+    sjson_speed_1 = _generate_subs(speed, 1, sjson_subs)
+
+    for i in range(len(sjson_speed_1['start'])):
+        item = SubRipItem(
+            index=i,
+            start=SubRipTime(milliseconds=sjson_speed_1['start'][i]),
+            end=SubRipTime(milliseconds=sjson_speed_1['end'][i]),
+            text=sjson_speed_1['text'][i]
+        )
+        output += (unicode(item))
+        output += '\n'
+    return output

lms/djangoapps/courseware/tests/test_video_mongo.py

@@ -5,7 +5,6 @@ from mock import patch, PropertyMock
 import os
 import tempfile
 import textwrap
-import unittest
 from functools import partial
 
 from xmodule.contentstore.content import StaticContent
@@ -20,7 +19,6 @@ from xmodule.exceptions import NotFoundError
 
 class TestVideo(BaseTestXmodule):
     """Integration tests: web client + mongo."""
-
     CATEGORY = "video"
     DATA = SOURCE_XML
     METADATA = {}
@@ -71,7 +69,7 @@ class TestVideoYouTube(TestVideo):
             'general_speed': 1.0,
             'start': 3603.0,
             'sub': u'a_sub_file.srt.sjson',
-            'track': '',
+            'track': None,
             'youtube_streams': _create_youtube_string(self.item_module),
             'autoplay': settings.FEATURES.get('AUTOPLAY_VIDEOS', False),
             'yt_test_timeout': 1500,
@@ -126,7 +124,7 @@ class TestVideoNonYouTube(TestVideo):
             'general_speed': 1.0,
             'start': 3603.0,
             'sub': u'a_sub_file.srt.sjson',
-            'track': '',
+            'track': None,
             'youtube_streams': '1.00:OEoXaMPEzfM',
             'autoplay': settings.FEATURES.get('AUTOPLAY_VIDEOS', True),
             'yt_test_timeout': 1500,
@@ -145,7 +143,6 @@ class TestGetHtmlMethod(BaseTestXmodule):
     '''
     CATEGORY = "video"
     DATA = SOURCE_XML
-    maxDiff = None
     METADATA = {}
 
     def setUp(self):
@@ -222,14 +219,13 @@ class TestGetHtmlMethod(BaseTestXmodule):
             )
 
             self.initialize_module(data=DATA)
-            # track_url = self.item_descriptor.xmodule_runtime.handler_url(self.item_module, 'download_transcript')
+            track_url = self.item_descriptor.xmodule_runtime.handler_url(self.item_module, 'download_transcript')
 
             context = self.item_module.render('student_view').content
 
             expected_context.update({
                 'ajax_url': self.item_descriptor.xmodule_runtime.ajax_url + '/save_user_state',
-                # 'track': track_url if data['expected_track_url'] == u'a_sub_file.srt.sjson' else data['expected_track_url'],
-                'track': u'http://www.example.com/track' if data['track'] else '',
+                'track': track_url if data['expected_track_url'] == u'a_sub_file.srt.sjson' else data['expected_track_url'],
                 'sub': data['sub'],
                 'id': self.item_module.location.html_id(),
             })
@@ -312,7 +308,7 @@ class TestGetHtmlMethod(BaseTestXmodule):
             'general_speed': 1.0,
             'start': 3603.0,
             'sub': u'a_sub_file.srt.sjson',
-            'track': '',
+            'track': None,
             'youtube_streams': '1.00:OEoXaMPEzfM',
             'autoplay': settings.FEATURES.get('AUTOPLAY_VIDEOS', True),
             'yt_test_timeout': 1500,
@@ -426,7 +422,7 @@ class TestVideoDescriptorInitialization(BaseTestXmodule):
             },
         }
         metadata = {
-            'track': '',
+            'track': None,
             'source': 'http://example.org/video.mp4',
             'html5_sources': ['http://youtu.be/OEoXaMPEzfM.mp4'],
         }
@@ -450,85 +446,6 @@ class TestVideoDescriptorInitialization(BaseTestXmodule):
         self.assertNotIn('source', fields)
         self.assertFalse(self.item_module.download_video)
 
-    @unittest.skip('Skipped due to the reason described in BLD-811')
-    def test_track_is_not_empty(self):
-        metatdata = {
-            'track': 'http://example.org/track',
-        }
-
-        self.initialize_module(metadata=metatdata)
-        fields = self.item_descriptor.editable_metadata_fields
-
-        self.assertIn('track', fields)
-        self.assertEqual(self.item_module.track, 'http://example.org/track')
-        self.assertTrue(self.item_module.download_track)
-        self.assertTrue(self.item_module.track_visible)
-
-    @unittest.skip('Skipped due to the reason described in BLD-811')
-    @patch('xmodule.x_module.XModuleDescriptor.editable_metadata_fields', new_callable=PropertyMock)
-    def test_download_track_is_explicitly_set(self, mock_editable_fields):
-        mock_editable_fields.return_value = {
-            'download_track': {
-                'default_value': False,
-                'explicitly_set': True,
-                'display_name': 'Transcript Download Allowed',
-                'help': 'Show a link beneath the video to allow students to download the transcript.',
-                'type': 'Boolean',
-                'value': False,
-                'field_name': 'download_track',
-                'options': [
-                    {'display_name': "True", "value": True},
-                    {'display_name': "False", "value": False}
-                ],
-            },
-            'track': {
-                'default_value': '',
-                'explicitly_set': False,
-                'display_name': 'Download Transcript',
-                'help': 'The external URL to download the timed transcript track.',
-                'type': 'Generic',
-                'value': u'http://example.org/track',
-                'field_name': 'track',
-                'options': [],
-            },
-            'source': {
-                'default_value': '',
-                'explicitly_set': False,
-                'display_name': 'Download Video',
-                'help': 'The external URL to download the video.',
-                'type': 'Generic',
-                'value': u'',
-                'field_name': 'source',
-                'options': [],
-            },
-        }
-        metadata = {
-            'source': '',
-            'track': 'http://example.org/track',
-        }
-
-        self.initialize_module(metadata=metadata)
-        fields = self.item_descriptor.editable_metadata_fields
-
-        self.assertIn('track', fields)
-        self.assertEqual(self.item_module.track, 'http://example.org/track')
-        self.assertFalse(self.item_module.download_track)
-        self.assertTrue(self.item_module.track_visible)
-
-    @unittest.skip('Skipped due to the reason described in BLD-811')
-    def test_track_is_empty(self):
-        metatdata = {
-            'track': '',
-        }
-
-        self.initialize_module(metadata=metatdata)
-        fields = self.item_descriptor.editable_metadata_fields
-
-        self.assertNotIn('track', fields)
-        self.assertEqual(self.item_module.track, '')
-        self.assertFalse(self.item_module.download_track)
-        self.assertFalse(self.item_module.track_visible)
-
 
 class TestVideoGetTranscriptsMethod(TestVideo):
     """
@@ -552,7 +469,7 @@ class TestVideoGetTranscriptsMethod(TestVideo):
         self.item_module.render('student_view')
         item = self.item_descriptor.xmodule_runtime.xmodule_instance
 
-        good_sjson = _create_file(content="""
+        good_sjson = _create_file(content=textwrap.dedent("""\
                 {
                   "start": [
                     270,
@@ -567,13 +484,22 @@ class TestVideoGetTranscriptsMethod(TestVideo):
                     "Let's start with what is on your screen right now."
                   ]
                 }
-            """)
+            """))
 
         _upload_file(good_sjson, self.item_module.location)
         subs_id = _get_subs_id(good_sjson.name)
 
         text = item.get_transcript(subs_id)
-        expected_text = "Hi, welcome to Edx.\nLet's start with what is on your screen right now."
+        expected_text = textwrap.dedent("""\
+            0
+            00:00:00,270 --> 00:00:02,720
+            Hi, welcome to Edx.
+
+            1
+            00:00:02,720 --> 00:00:05,430
+            Let's start with what is on your screen right now.
+
+            """)
 
         self.assertEqual(text, expected_text)