[khanacademy] Add support (Fixes #2066)

1 files changed, 10 insertions, 0 deletions

diff --git a/youtube_dl/extractor/common.py b/youtube_dl/extractor/common.py
index 2a5e8076c..0ec365eaa 100644
--- a/youtube_dl/extractor/common.py
+++ b/youtube_dl/extractor/common.py
@@ -1,4 +1,5 @@
 import base64
+import json
 import os
 import re
 import socket
@@ -260,6 +261,15 @@ class InfoExtractor(object):
             xml_string = transform_source(xml_string)
         return xml.etree.ElementTree.fromstring(xml_string.encode('utf-8'))
 
+    def _download_json(self, url_or_request, video_id,
+                       note=u'Downloading JSON metadata',
+                       errnote=u'Unable to download JSON metadata'):
+        json_string = self._download_webpage(url_or_request, video_id, note, errnote)
+        try:
+            return json.loads(json_string)
+        except ValueError as ve:
+            raise ExtractorError('Failed to download JSON', cause=ve)
+
     def report_warning(self, msg, video_id=None):
         idstr = u'' if video_id is None else u'%s: ' % video_id
         self._downloader.report_warning(