url preview: Show inline images as previews for oEmbed photo pages.

zerver/lib/bugdown/__init__.py

@@ -368,7 +368,23 @@ def add_a(
         desc_div = markdown.util.etree.SubElement(summary_div, "desc")
         desc_div.set("class", "message_inline_image_desc")
 
+def add_oembed_data(root: Element, link: str, extracted_data: Dict[str, Any]) -> bool:
+    type_ = extracted_data.get('type', '')
+    title = extracted_data.get('title', link)
+
+    if type_ == 'photo':
+        image = extracted_data.get('image')
+        if image:
+            add_a(root, image, link, title=title)
+            return True
+
+    return False
+
 def add_embed(root: Element, link: str, extracted_data: Dict[str, Any]) -> None:
+    oembed = extracted_data.get('oembed', False)
+    if oembed and add_oembed_data(root, link, extracted_data):
+        return
+
     container = markdown.util.etree.SubElement(root, "div")
     container.set("class", "message_embed")
 

zerver/lib/url_preview/oembed/__init__.py

@@ -11,4 +11,10 @@ def get_oembed_data(url: str,
         return None
 
     data['image'] = data.get('thumbnail_url')
+    type_ = data.get('type', '')
+    image = data.get('url', data.get('image'))
+    if type_ == 'photo' and image:
+        # Add a key to identify oembed metadata as opposed to other metadata
+        data['oembed'] = True
+
     return data

zerver/lib/url_preview/preview.py

@@ -81,6 +81,8 @@ def get_link_embed_data(url: str,
     # 2. Open Graph
     # 3. Meta tags
     data = get_oembed_data(url, maxwidth=maxwidth, maxheight=maxheight) or {}
+    if data.get('oembed'):
+        return data
     response = requests.get(url, stream=True, headers=HEADERS, timeout=TIMEOUT)
     if response.ok:
         og_data = OpenGraphParser(response.text).extract_data()

zerver/tests/test_link_embed.py

@@ -59,6 +59,31 @@ class OembedTestCase(ZulipTestCase):
         assert data is not None  # allow mypy to infer data is indexable
         self.assertEqual(data['title'], response_data['title'])
 
+    @mock.patch('pyoembed.requests.get')
+    def test_photo_provider(self, get: Any) -> None:
+        get.return_value = response = mock.Mock()
+        response.headers = {'content-type': 'application/json'}
+        response.ok = True
+        response_data = {
+            'type': 'photo',
+            'thumbnail_url': 'https://scontent.cdninstagram.com/t51.2885-15/n.jpg',
+            'url': 'https://scontent.cdninstagram.com/t51.2885-15/n.jpg',
+            'thumbnail_width': 640,
+            'thumbnail_height': 426,
+            'title': 'NASA',
+            'html': '<p>test</p>',
+            'version': '1.0',
+            'width': 658,
+            'height': 400}
+        response.text = ujson.dumps(response_data)
+        url = 'http://imgur.com/photo/158727223'
+        data = get_oembed_data(url)
+        self.assertIsInstance(data, dict)
+        self.assertIn('title', data)
+        assert data is not None  # allow mypy to infer data is indexable
+        self.assertEqual(data['title'], response_data['title'])
+        self.assertTrue(data['oembed'])
+
     @mock.patch('pyoembed.requests.get')
     def test_error_request(self, get: Any) -> None:
         get.return_value = response = mock.Mock()