@@ -1453,6 +1453,61 @@ class _ZulipContentParser {
14531453 return tableNode ?? UnimplementedBlockContentNode (htmlNode: tableElement);
14541454 }
14551455
1456+ void parseMathBlocks (dom.NodeList nodes, List <BlockContentNode > result) {
1457+ assert (nodes.isNotEmpty);
1458+ assert ((() {
1459+ final first = nodes.first;
1460+ return first is dom.Element
1461+ && first.localName == 'span'
1462+ && first.className == 'katex-display' ;
1463+ })());
1464+
1465+ final firstChild = nodes.first as dom.Element ;
1466+ final texSource = _parseMath (firstChild, block: true );
1467+ if (texSource != null ) {
1468+ result.add (MathBlockNode (texSource: texSource, debugHtmlNode: firstChild));
1469+ } else {
1470+ result.add (UnimplementedBlockContentNode (htmlNode: firstChild));
1471+ }
1472+
1473+ // Skip further checks if there was only a single child.
1474+ if (nodes.length == 1 ) return ;
1475+
1476+ // The case with the `<br>\n` can happen when at the end of a quote;
1477+ // it seems like a glitch in the server's Markdown processing,
1478+ // so hopefully there just aren't any further such glitches.
1479+ bool hasTrailingBreakNewline = false ;
1480+ if (nodes
1481+ case [..., dom.Element (localName: 'br' ), dom.Text (text: '\n ' )]
1482+ ) {
1483+ hasTrailingBreakNewline = true ;
1484+ }
1485+
1486+ final length = hasTrailingBreakNewline
1487+ ? nodes.length - 2
1488+ : nodes.length;
1489+ for (int i = 1 ; i < length; i++ ) {
1490+ final child = nodes[i];
1491+
1492+ // If there are multiple <span class="katex-display"> nodes in a <p>
1493+ // each node is interleaved by '\n\n'. Whitespaces are ignored in HTML
1494+ // on web but each node has `display: block`, which renders each node
1495+ // on a newline. Since the emitted MathBlockNode are BlockContentNode,
1496+ // we skip these newlines here to replicate the same behavior as on web.
1497+ if (child case dom.Text (text: '\n\n ' )) continue ;
1498+
1499+ if (child case dom.Element (localName: 'span' , className: 'katex-display' )) {
1500+ final texSource = _parseMath (child, block: true );
1501+ if (texSource != null ) {
1502+ result.add (MathBlockNode (texSource: texSource, debugHtmlNode: child));
1503+ continue ;
1504+ }
1505+ }
1506+
1507+ result.add (UnimplementedBlockContentNode (htmlNode: child));
1508+ }
1509+ }
1510+
14561511 BlockContentNode parseBlockContent (dom.Node node) {
14571512 final debugHtmlNode = kDebugMode ? node : null ;
14581513 if (node is ! dom.Element ) {
@@ -1471,21 +1526,6 @@ class _ZulipContentParser {
14711526 }
14721527
14731528 if (localName == 'p' && className.isEmpty) {
1474- // Oddly, the way a math block gets encoded in Zulip HTML is inside a <p>.
1475- if (element.nodes case [dom.Element (localName: 'span' ) && var child, ...]) {
1476- if (child.className == 'katex-display' ) {
1477- if (element.nodes case [_]
1478- || [_, dom.Element (localName: 'br' ),
1479- dom.Text (text: "\n " )]) {
1480- // This might be too specific; we'll find out when we do #190.
1481- // The case with the `<br>\n` can happen when at the end of a quote;
1482- // it seems like a glitch in the server's Markdown processing,
1483- // so hopefully there just aren't any further such glitches.
1484- return parseMathBlock (child);
1485- }
1486- }
1487- }
1488-
14891529 final parsed = parseBlockInline (element.nodes);
14901530 return ParagraphNode (debugHtmlNode: debugHtmlNode,
14911531 links: parsed.links,
@@ -1599,6 +1639,18 @@ class _ZulipContentParser {
15991639 for (final node in nodes) {
16001640 if (node is dom.Text && (node.text == '\n ' )) continue ;
16011641
1642+ // Oddly, the way math blocks get encoded in Zulip HTML is inside a <p>.
1643+ // And there can be multiple math blocks inside the paragraph node, so
1644+ // handle it explicitly here.
1645+ if (node case
1646+ dom.Element (localName: 'p' , nodes: [
1647+ dom.Element (localName: 'span' , className: 'katex-display' ), ...])) {
1648+ if (currentParagraph.isNotEmpty) consumeParagraph ();
1649+ if (imageNodes.isNotEmpty) consumeImageNodes ();
1650+ parseMathBlocks (node.nodes, result);
1651+ continue ;
1652+ }
1653+
16021654 if (_isPossibleInlineNode (node)) {
16031655 if (imageNodes.isNotEmpty) {
16041656 consumeImageNodes ();
@@ -1642,6 +1694,17 @@ class _ZulipContentParser {
16421694 continue ;
16431695 }
16441696
1697+ // Oddly, the way math blocks get encoded in Zulip HTML is inside a <p>.
1698+ // And there can be multiple math blocks inside the paragraph node, so
1699+ // handle it explicitly here.
1700+ if (node case
1701+ dom.Element (localName: 'p' , nodes: [
1702+ dom.Element (localName: 'span' , className: 'katex-display' ), ...])) {
1703+ if (imageNodes.isNotEmpty) consumeImageNodes ();
1704+ parseMathBlocks (node.nodes, result);
1705+ continue ;
1706+ }
1707+
16451708 final block = parseBlockContent (node);
16461709 if (block is ImageNode ) {
16471710 imageNodes.add (block);
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