validateValue method

  1. @override
String? validateValue(
  1. String valueCandidate
)
override

Validates the value. Returns null if the value is valid, otherwise an error message. Call validate() instead of this method when using the validator.

Implementation

@override
String? validateValue(String valueCandidate) {
  final int? cvc = int.tryParse(valueCandidate);
  if (cvc == null || valueCandidate.length < 3 || valueCandidate.length > 4) {
    return errorText;
  }
  return null;
}