nip static method

String? Function(String?) nip({
  1. String? message,
})

Validates employee ID (NIP)

Implementation

static String? Function(String?) nip({String? message}) {
  return (String? value) {
    if (value == null || value.trim().isEmpty) {
      return null;
    }

    final cleaned = value.replaceAll(RegExp(r'[\s-]'), '');

    // NIP is usually 18 digits
    if (cleaned.length != 18) {
      return message ?? _defaultMessages['nip'];
    }

    // Validate NIP format (18 digits)
    if (!RegExp(r'^[0-9]{18}$').hasMatch(cleaned)) {
      return message ?? _defaultMessages['nip'];
    }

    return null;
  };
}