Upgrade markdown parser for tables and footnotes

src/Service/SnipParser/Markdown/MarkdownParser.php

@@ -6,6 +6,9 @@ use App\Repository\SnipRepository;
 use App\Service\SnipParser\AbstractParser;
 use League\CommonMark\Event\DocumentParsedEvent;
 use League\CommonMark\Extension\CommonMark\Node\Inline\Link;
+use League\CommonMark\Extension\DefaultAttributes\DefaultAttributesExtension;
+use League\CommonMark\Extension\Footnote\FootnoteExtension;
+use League\CommonMark\Extension\Table\Table;
 use League\CommonMark\GithubFlavoredMarkdownConverter;
 use League\CommonMark\Node\Inline\Text;
 use League\CommonMark\Node\Query;
@@ -23,12 +26,24 @@ class MarkdownParser extends AbstractParser
 
     public function safeParseView(string $content): string
     {
-        $converter = new GithubFlavoredMarkdownConverter();
+        $config = [
+            'default_attributes' => [
+                Table::class => [
+                    'class' => 'table table-hover',
+                ],
+                Link::class => [
+                    'class' => 'btn btn-sm btn-secondary',
+                    'target' => '_blank',
+                ],
+            ],
+        ];
+
+        $converter = new GithubFlavoredMarkdownConverter($config);
         $converter
             ->getEnvironment()
-            ->addExtension(new HighlightExtension(
-                new Highlighter()->withGutter()
-            ))
+            ->addExtension(new HighlightExtension(new Highlighter()->withGutter()))
+            ->addExtension(new FootnoteExtension())
+            ->addExtension(new DefaultAttributesExtension())
             ->addEventListener(DocumentParsedEvent::class, $this->documentParsed(...))
         ;
         return $converter->convert($content);
@@ -43,9 +58,14 @@ class MarkdownParser extends AbstractParser
             ->findAll($document)
         ;
 
+        /** @var Link $linkNode */
         foreach ($linkNodes as $linkNode) {
             $url = $linkNode->getUrl();
 
+            if (!is_int($url)) {
+                continue;
+            }
+
             $snip = $this->snipRepo->find($url);
             if ($snip === null) {
                 continue;