snapshot of https://github.com/zulip/zulip.git @ 48c69911c7dd4e03b20552eb3bd77ad8151c1357 (2026-09-15)

zerver/lib/url_preview/parsers/generic.py

@@ -0,0 +1,61 @@
+from urllib.parse import urlsplit
+
+from bs4.element import Tag
+from typing_extensions import override
+
+from zerver.lib.url_preview.parsers.base import BaseParser
+from zerver.lib.url_preview.types import UrlEmbedData
+
+
+class GenericParser(BaseParser):
+    @override
+    def extract_data(self) -> UrlEmbedData:
+        return UrlEmbedData(
+            title=self._get_title(),
+            description=self._get_description(),
+            image=self._get_image(),
+        )
+
+    def _get_title(self) -> str | None:
+        soup = self._soup
+        if soup.title and soup.title.text != "":
+            return soup.title.text
+        if soup.h1 and soup.h1.text != "":
+            return soup.h1.text
+        return None
+
+    def _get_description(self) -> str | None:
+        soup = self._soup
+        meta_description = soup.find("meta", attrs={"name": "description"})
+        if isinstance(meta_description, Tag) and meta_description.get("content", "") != "":
+            assert isinstance(meta_description["content"], str)
+            return meta_description["content"]
+        first_h1 = soup.find("h1")
+        if first_h1:
+            first_p = first_h1.find_next("p")
+            if first_p and first_p.text != "":
+                return first_p.text
+        first_p = soup.find("p")
+        if first_p and first_p.text != "":
+            return first_p.text
+        return None
+
+    def _get_image(self) -> str | None:
+        """
+        Finding a first image after the h1 header.
+        Presumably it will be the main image.
+        """
+        soup = self._soup
+        first_h1 = soup.find("h1")
+        if first_h1:
+            first_image = first_h1.find_next_sibling("img", src=True)
+            if isinstance(first_image, Tag) and first_image["src"] != "":
+                assert isinstance(first_image["src"], str)
+                try:
+                    # We use urlsplit and not URLValidator because we
+                    # need to support relative URLs.
+                    urlsplit(first_image["src"])
+                except ValueError:
+                    return None
+                return first_image["src"]
+        return None