issue-198 nesting shortcodes

src/php/front-end/class-front-end.php

@@ -28,6 +28,11 @@ class Front_End {
 	 */
 	const PRISM_HANDLE = 'code-snippets-prism';
 
+	/**
+	 * Maximum depth for shortcode recursion.
+	 */
+	const MAX_SHORTCODE_DEPTH = 5;
+
 	/**
 	 * Class constructor
 	 */
@@ -235,7 +240,7 @@ protected function convert_boolean_attribute_flags( array $atts, array $boolean_
 	 *
 	 * @return string Evaluated shortcode content.
 	 */
-	protected function evaluate_shortcode_content( Snippet $snippet, array $atts ): string {
+	protected function evaluate_shortcode_content( Snippet $snippet, array $atts ): string {	
 		if ( empty( $atts['php'] ) ) {
 			return $snippet->code;
 		}
@@ -325,8 +330,25 @@ public function render_content_shortcode( array $atts ): string {
 			// Remove this shortcode from the list to prevent recursion.
 			remove_shortcode( self::CONTENT_SHORTCODE );
 
-			// Evaluate shortcodes.
-			$content = do_shortcode( $atts['format'] ? shortcode_unautop( $content ) : $content );
+			// Recursion depth is limited to prevent infinite loops.
+			static $depth = 0;
+			$max_depth = self::MAX_SHORTCODE_DEPTH;
+
+			// Find the shortcode in the content and replace it with the evaluated content.
+			$content = preg_replace_callback(
+				'/\[' . self::CONTENT_SHORTCODE . '([^\]]*)\]/',
+				function ($matches) use (&$depth, $max_depth) {
+					if ($depth >= $max_depth) {
+						return '<!-- Max shortcode depth reached -->';
+					}
+					$depth++;
+					$atts = shortcode_parse_atts($matches[1]);
+					$result = $this->render_content_shortcode($atts);
+					$depth--;
+					return $result;
+				},
+				$content
+			);
 
 			// Add this shortcode back to the list.
 			add_shortcode( self::CONTENT_SHORTCODE, [ $this, 'render_content_shortcode' ] );