pin static method

String? pin(
  1. String? value, {
  2. int length = 6,
  3. String? errorMsg,
})

3️⃣ OTP PIN Number Validator

Implementation

static String? pin(String? value, {int length = 6, String? errorMsg}) {
  if (value == null || value.isEmpty) return 'PIN is required';
  final regex = RegExp(r'^\d{' + length.toString() + r'}$');
  return regex.hasMatch(value)
      ? null
      : errorMsg ?? 'Enter a $length-digit PIN';
}