Initial release of Link Heading Plugin

syntax.php

@@ -0,0 +1,120 @@
+<?php
+
+/**
+ * DokuWiki Plugin linkheading (Syntax Component)
+ *
+ * Creates clickable headings linking to internal DokuWiki pages.
+ *
+ * @license MIT
+ * @author Jens Mohr
+ */
+
+use dokuwiki\Extension\SyntaxPlugin;
+
+class syntax_plugin_linkheading extends SyntaxPlugin
+{
+    /**
+     * @return string Syntax mode type
+     */
+    public function getType()
+    {
+        return 'substition';
+    }
+
+    /**
+     * @return string Paragraph type
+     */
+    public function getPType()
+    {
+        return 'block';
+    }
+
+    /**
+     * @return int Sort order
+     */
+    public function getSort()
+    {
+        return 155;
+    }
+
+    /**
+     * Connect syntax pattern to lexer.
+     *
+     * @param string $mode Parser mode
+     */
+    public function connectTo($mode)
+    {
+        $this->Lexer->addSpecialPattern(
+            '\{\{linkheading>[^}]+\}\}',
+            $mode,
+            'plugin_linkheading'
+        );
+    }
+
+    /**
+     * Parse plugin syntax.
+     *
+     * Supported forms:
+     *
+     * {{linkheading>target|Heading}}
+     * {{linkheading>4|target|Heading}}
+     *
+     * @inheritDoc
+     */
+    public function handle($match, $state, $pos, Doku_Handler $handler)
+    {
+        $content = substr($match, 14, -2);
+        $parts = explode('|', $content);
+
+        if (
+            count($parts) >= 3 &&
+            preg_match('/^[1-6]$/', trim($parts[0]))
+        ) {
+            $level  = (int) trim(array_shift($parts));
+            $target = trim(array_shift($parts));
+            $title  = trim(implode('|', $parts));
+        } else {
+            $level  = 2;
+            $target = trim(array_shift($parts));
+            $title  = trim(implode('|', $parts));
+        }
+
+        if ($title === '') {
+            $title = $target;
+        }
+
+        return [
+            'level'  => $level,
+            'target' => $target,
+            'title'  => $title,
+        ];
+    }
+
+    /**
+     * Render linked heading.
+     *
+     * @inheritDoc
+     */
+    public function render($mode, Doku_Renderer $renderer, $data)
+    {
+        $level  = max(1, min(6, (int) $data['level']));
+        $target = $data['target'];
+        $title  = $data['title'];
+
+        if ($mode === 'xhtml') {
+            $renderer->doc .= '<h' . $level . ' class="linkheading">';
+            $renderer->internallink($target, $title);
+            $renderer->doc .= '</h' . $level . '>';
+
+            return true;
+        }
+
+        if ($mode === 'metadata') {
+            $renderer->internallink($target, $title);
+
+            return true;
+        }
+
+        return false;
+    }
+}