Add setting for disabling inline image preview.

(imported from commit 2321390eb14cfe5701347861b9ae5ad6fdac0cbb)

zerver/lib/bugdown/__init__.py

@@ -158,6 +158,8 @@ class InlineHttpsProcessor(markdown.treeprocessors.Treeprocessor):
 
 class InlineInterestingLinkProcessor(markdown.treeprocessors.Treeprocessor):
     def is_image(self, url):
+        if not settings.INLINE_IMAGE_PREVIEW:
+            return False
         parsed_url = urlparse.urlparse(url)
         # List from http://support.google.com/chromeos/bin/answer.py?hl=en&answer=183093
         for ext in [".bmp", ".gif", ".jpg", "jpeg", ".png", ".webp"]:
@@ -175,6 +177,8 @@ class InlineInterestingLinkProcessor(markdown.treeprocessors.Treeprocessor):
         return None
 
     def youtube_image(self, url):
+        if not settings.INLINE_IMAGE_PREVIEW:
+            return None
         # Youtube video id extraction regular expression from http://pastebin.com/KyKAFv1s
         # If it matches, match.group(2) is the video id.
         youtube_re = r'^((?:https?://)?(?:youtu\.be/|(?:\w+\.)?youtube(?:-nocookie)?\.com/)(?:(?:(?:v|embed)/)|(?:(?:watch(?:_popup)?(?:\.php)?)?(?:\?|#!?)(?:.+&)?v=)))?([0-9A-Za-z_-]+)(?(1).+)?$'
@@ -328,8 +332,7 @@ class InlineInterestingLinkProcessor(markdown.treeprocessors.Treeprocessor):
                 if embedly_client.is_supported(url):
                     embedly_urls.append(url)
                     continue
-            # NOTE: The youtube code below is inactive at least on
-            # staging because embedy.ly is currently handling those
+            # NOTE: settings.USING_EMBEDLY will prevent the below from running
             youtube = self.youtube_image(url)
             if youtube is not None:
                 add_a(root, youtube, url)

zproject/local_settings_template.py

@@ -61,6 +61,10 @@ ENABLE_FEEDBACK = True
 # questions.
 ERROR_REPORTING = True
 
+# Controls whether or not Zulip will provide inline image preview when
+# a link to an image is referenced in a message.
+INLINE_IMAGE_PREVIEW = True
+
 # By default, files uploaded by users and user avatars are stored
 # directly on the Zulip server.  If file storage in Amazon S3 (or
 # elsewhere, e.g. your corporate fileshare) is desired, please contact

zproject/settings.py

@@ -258,6 +258,7 @@ DEFAULT_SETTINGS = {'TWITTER_CONSUMER_KEY': '',
                     'FEEDBACK_BOT_NAME': 'Zulip Feedback Bot',
                     'API_SUPER_USERS': set(),
                     'ADMINS': '',
+                    'INLINE_IMAGE_PREVIEW': True,
                     'ENABLE_FEEDBACK': True,
                     }