@@ -581,6 +581,57 @@ class TableCellNode extends BlockInlineContainerNode {
581581 }
582582}
583583
584+ // Ref:
585+ // https://ogp.me/
586+ // https://oembed.com/
587+ class LinkPreviewNode extends BlockContentNode {
588+ const LinkPreviewNode ({
589+ super .debugHtmlNode,
590+ required this .hrefUrl,
591+ required this .imageSrcUrl,
592+ required this .title,
593+ required this .description,
594+ });
595+
596+ /// The URL from which this preview data was retrieved.
597+ final String hrefUrl;
598+
599+ /// The image URL representing the webpage, content value
600+ /// of `og:image` HTML meta property.
601+ final String imageSrcUrl;
602+
603+ /// Represents the webpage title, derived from either
604+ /// the content of the `og:title` HTML meta property or
605+ /// the <title> HTML element.
606+ final String ? title;
607+
608+ /// Description about the webpage, content value of
609+ /// `og:description` HTML meta property.
610+ final String ? description;
611+
612+ @override
613+ bool operator == (Object other) {
614+ return other is LinkPreviewNode
615+ && other.hrefUrl == hrefUrl
616+ && other.imageSrcUrl == imageSrcUrl
617+ && other.title == title
618+ && other.description == description;
619+ }
620+
621+ @override
622+ int get hashCode =>
623+ Object .hash ('LinkPreviewNode' , hrefUrl, imageSrcUrl, title, description);
624+
625+ @override
626+ void debugFillProperties (DiagnosticPropertiesBuilder properties) {
627+ super .debugFillProperties (properties);
628+ properties.add (StringProperty ('hrefUrl' , hrefUrl));
629+ properties.add (StringProperty ('imageSrcUrl' , imageSrcUrl));
630+ properties.add (StringProperty ('title' , title));
631+ properties.add (StringProperty ('description' , description));
632+ }
633+ }
634+
584635/// A content node that expects an inline layout context from its parent.
585636///
586637/// When rendered into a Flutter widget tree, an inline content node
@@ -1448,6 +1499,81 @@ class _ZulipContentParser {
14481499 return tableNode ?? UnimplementedBlockContentNode (htmlNode: tableElement);
14491500 }
14501501
1502+ static final _linkPreviewImageSrcRegexp = RegExp (r'background-image: url\("(.+)"\)' );
1503+
1504+ BlockContentNode parseLinkPreviewNode (dom.Element divElement) {
1505+ assert (_debugParserContext == _ParserContext .block);
1506+ assert (divElement.localName == 'div'
1507+ && divElement.className == 'message_embed' );
1508+
1509+ final result = () {
1510+ if (divElement.nodes.length != 2 ) return null ;
1511+
1512+ final first = divElement.nodes.first;
1513+ if (first is ! dom.Element ) return null ;
1514+ if (first.localName != 'a' ) return null ;
1515+ if (first.className != 'message_embed_image' ) return null ;
1516+ if (first.nodes.isNotEmpty) return null ;
1517+
1518+ final imageHref = first.attributes['href' ];
1519+ if (imageHref == null ) return null ;
1520+
1521+ final styleAttr = first.attributes['style' ];
1522+ if (styleAttr == null ) return null ;
1523+ final match = _linkPreviewImageSrcRegexp.firstMatch (styleAttr);
1524+ if (match == null ) return null ;
1525+ final imageSrcUrl = match.group (1 );
1526+ if (imageSrcUrl == null ) return null ;
1527+
1528+ final second = divElement.nodes.last;
1529+ if (second is ! dom.Element ) return null ;
1530+ if (second.localName != 'div' ) return null ;
1531+ if (second.className != 'data-container' ) return null ;
1532+ if (second.nodes.isEmpty) return null ;
1533+ if (second.nodes.length > 2 ) return null ;
1534+
1535+ String ? title, description;
1536+ for (final node in second.nodes) {
1537+ if (node is ! dom.Element ) return null ;
1538+ if (node.localName != 'div' ) return null ;
1539+
1540+ switch (node.className) {
1541+ case 'message_embed_title' :
1542+ if (node.nodes.length != 1 ) return null ;
1543+ final child = node.nodes.single;
1544+ if (child is ! dom.Element ) return null ;
1545+ if (child.localName != 'a' ) return null ;
1546+ if (child.className.isNotEmpty) return null ;
1547+ if (child.nodes.length != 1 ) return null ;
1548+
1549+ final titleHref = child.attributes['href' ];
1550+ // Make sure both image hyperlink and title hyperlink are same.
1551+ if (imageHref != titleHref) return null ;
1552+ final grandchild = child.nodes.single;
1553+ if (grandchild is ! dom.Text ) return null ;
1554+ title = grandchild.text;
1555+
1556+ case 'message_embed_description' :
1557+ if (node.nodes.length != 1 ) return null ;
1558+ final child = node.nodes.single;
1559+ if (child is ! dom.Text ) return null ;
1560+ description = child.text;
1561+
1562+ default :
1563+ return null ;
1564+ }
1565+ }
1566+
1567+ return LinkPreviewNode (
1568+ hrefUrl: imageHref,
1569+ imageSrcUrl: imageSrcUrl,
1570+ title: title,
1571+ description: description);
1572+ }();
1573+
1574+ return result ?? UnimplementedBlockContentNode (htmlNode: divElement);
1575+ }
1576+
14511577 BlockContentNode parseBlockContent (dom.Node node) {
14521578 assert (_debugParserContext == _ParserContext .block);
14531579 final debugHtmlNode = kDebugMode ? node : null ;
@@ -1545,6 +1671,10 @@ class _ZulipContentParser {
15451671 }
15461672 }
15471673
1674+ if (localName == 'div' && className == 'message_embed' ) {
1675+ return parseLinkPreviewNode (element);
1676+ }
1677+
15481678 // TODO more types of node
15491679 return UnimplementedBlockContentNode (htmlNode: node);
15501680 }
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