Add timeline of public posts about a trending link in web UI (#30840)

app/javascript/mastodon/features/link_timeline/index.tsx

@@ -0,0 +1,76 @@
+import { useRef, useEffect, useCallback } from 'react';
+
+import { Helmet } from 'react-helmet';
+import { useParams } from 'react-router-dom';
+
+import ExploreIcon from '@/material-icons/400-24px/explore.svg?react';
+import { expandLinkTimeline } from 'mastodon/actions/timelines';
+import Column from 'mastodon/components/column';
+import { ColumnHeader } from 'mastodon/components/column_header';
+import StatusListContainer from 'mastodon/features/ui/containers/status_list_container';
+import type { Card } from 'mastodon/models/status';
+import { useAppDispatch, useAppSelector } from 'mastodon/store';
+
+export const LinkTimeline: React.FC<{
+  multiColumn: boolean;
+}> = ({ multiColumn }) => {
+  const { url } = useParams<{ url: string }>();
+  const decodedUrl = url ? decodeURIComponent(url) : undefined;
+  const dispatch = useAppDispatch();
+  const columnRef = useRef<Column>(null);
+  const firstStatusId = useAppSelector((state) =>
+    decodedUrl
+      ? // eslint-disable-next-line @typescript-eslint/no-unsafe-call, @typescript-eslint/no-unsafe-member-access
+        (state.timelines.getIn([`link:${decodedUrl}`, 'items', 0]) as string)
+      : undefined,
+  );
+  const story = useAppSelector((state) =>
+    firstStatusId
+      ? (state.statuses.getIn([firstStatusId, 'card']) as Card)
+      : undefined,
+  );
+
+  const handleHeaderClick = useCallback(() => {
+    columnRef.current?.scrollTop();
+  }, []);
+
+  const handleLoadMore = useCallback(
+    (maxId: string) => {
+      dispatch(expandLinkTimeline(decodedUrl, { maxId }));
+    },
+    [dispatch, decodedUrl],
+  );
+
+  useEffect(() => {
+    dispatch(expandLinkTimeline(decodedUrl));
+  }, [dispatch, decodedUrl]);
+
+  return (
+    <Column bindToDocument={!multiColumn} ref={columnRef} label={story?.title}>
+      <ColumnHeader
+        icon='explore'
+        iconComponent={ExploreIcon}
+        title={story?.title}
+        onClick={handleHeaderClick}
+        multiColumn={multiColumn}
+        showBackButton
+      />
+
+      <StatusListContainer
+        timelineId={`link:${decodedUrl}`}
+        onLoadMore={handleLoadMore}
+        trackScroll
+        scrollKey={`link_timeline-${decodedUrl}`}
+        bindToDocument={!multiColumn}
+      />
+
+      <Helmet>
+        <title>{story?.title}</title>
+        <meta name='robots' content='noindex' />
+      </Helmet>
+    </Column>
+  );
+};
+
+// eslint-disable-next-line import/no-default-export
+export default LinkTimeline;