decodeHtmlEntities function

String decodeHtmlEntities(String text)

Decodes the small set of HTML entities seen in search results and page content (named, decimal, and hexadecimal forms).

Implementation

String decodeHtmlEntities(String text) {
  if (!text.contains('&')) return text;
  return text.replaceAllMapped(
    RegExp(r'&(#x?[0-9a-fA-F]+|[a-zA-Z][a-zA-Z0-9]*);'),
    (match) {
      final body = match.group(1)!;
      if (body.startsWith('#x') || body.startsWith('#X')) {
        final code = int.tryParse(body.substring(2), radix: 16);
        return code == null ? match.group(0)! : String.fromCharCode(code);
      }
      if (body.startsWith('#')) {
        final code = int.tryParse(body.substring(1));
        return code == null ? match.group(0)! : String.fromCharCode(code);
      }
      return _namedEntities[body.toLowerCase()] ?? match.group(0)!;
    },
  );
}