Aside extension for Markdown

src/Commands/BaseBuildCommand.php

@@ -3,6 +3,7 @@
 namespace Ibis\Commands;
 
 use Ibis\Config;
+use Ibis\Markdown\Extensions\AsideExtension;
 use SplFileInfo;
 
 use Illuminate\Filesystem\Filesystem;
@@ -71,6 +72,7 @@ protected function buildHtml(string $path, array $config): Collection
         $environment->addExtension(new GithubFlavoredMarkdownExtension());
         $environment->addExtension(new TableExtension());
         $environment->addExtension(new FrontMatterExtension());
+        $environment->addExtension(new AsideExtension());
 
         $environment->addRenderer(FencedCode::class, new FencedCodeRenderer([
             'html', 'php', 'js', 'bash', 'json'

src/Markdown/Extensions/Aside.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace Ibis\Markdown\Extensions;
+
+use League\CommonMark\Node\Block\AbstractBlock;
+
+class Aside extends AbstractBlock
+{
+    public function __construct()
+    {
+        parent::__construct();
+    }
+
+}

src/Markdown/Extensions/AsideBlockParser.php

@@ -0,0 +1,52 @@
+<?php
+
+namespace Ibis\Markdown\Extensions;
+
+use League\CommonMark\Node\Block\AbstractBlock;
+use League\CommonMark\Parser\Block\BlockContinue;
+use League\CommonMark\Parser\Block\BlockContinueParserInterface;
+use League\CommonMark\Parser\Cursor;
+
+class AsideBlockParser implements BlockContinueParserInterface
+{
+    private readonly Aside $aside;
+
+    public function __construct()
+    {
+        $this->aside = new Aside();
+    }
+
+    public function getBlock(): AbstractBlock
+    {
+        return $this->aside;
+    }
+
+    public function isContainer(): bool
+    {
+        return true;
+    }
+
+    public function canHaveLazyContinuationLines(): bool
+    {
+        return false;
+    }
+
+    public function canContain(AbstractBlock $childBlock): bool
+    {
+        return true;
+    }
+
+    public function tryContinue(Cursor $cursor, BlockContinueParserInterface $activeBlockParser): ?BlockContinue
+    {
+        if ($cursor->getLine() === ":::") {
+            return BlockContinue::finished();
+        }
+
+        return BlockContinue::at($cursor);
+    }
+
+    public function addLine(string $line): void {}
+
+    public function closeBlock(): void {}
+
+}

src/Markdown/Extensions/AsideExtension.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace Ibis\Markdown\Extensions;
+
+use League\CommonMark\Environment\EnvironmentBuilderInterface;
+use League\CommonMark\Extension\ExtensionInterface;
+
+class AsideExtension implements ExtensionInterface
+{
+    public function register(EnvironmentBuilderInterface $environment): void
+    {
+        $environment->addBlockStartParser(new AsideParser())
+            ->addRenderer(Aside::class, new AsideRenderer());
+    }
+}

src/Markdown/Extensions/AsideParser.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace Ibis\Markdown\Extensions;
+
+use League\CommonMark\Parser\Block\BlockStart;
+use League\CommonMark\Parser\Block\BlockStartParserInterface;
+use League\CommonMark\Parser\Cursor;
+use League\CommonMark\Parser\MarkdownParserStateInterface;
+
+class AsideParser implements BlockStartParserInterface
+{
+    public function tryStart(Cursor $cursor, MarkdownParserStateInterface $parserState): ?BlockStart
+    {
+        if (!str_starts_with($cursor->getRemainder(), ':::note')) {
+            return BlockStart::none();
+        }
+
+        $cursor->advanceToNextNonSpaceOrTab();
+        $cursor->advanceToEnd();
+
+        return BlockStart::of(new AsideBlockParser())->at($cursor);
+    }
+}

src/Markdown/Extensions/AsideRenderer.php

@@ -0,0 +1,25 @@
+<?php
+
+namespace Ibis\Markdown\Extensions;
+
+use League\CommonMark\Node\Node;
+use League\CommonMark\Renderer\ChildNodeRendererInterface;
+use League\CommonMark\Renderer\NodeRendererInterface;
+use League\CommonMark\Util\HtmlElement;
+
+class AsideRenderer implements NodeRendererInterface
+{
+    public function render(Node $node, ChildNodeRendererInterface $childRenderer)
+    {
+        Aside::assertInstanceOf($node);
+
+        $attrs = $node->data->getData('attributes');
+        $contents = $childRenderer->renderNodes($node->children());
+
+        return new HtmlElement(
+            'blockquote',
+            ['class' => 'notice'],
+            new HtmlElement('div', $attrs->export(), $contents)
+        );
+    }
+}