creditCard method
FormFieldValidator
that requires the field's value to be a valid credit card number.
Implementation
static FormFieldValidator creditCard({
String errorText = "This field requires a valid credit card number.",
}) {
return (valueCandidate) {
if (valueCandidate != null && valueCandidate.isNotEmpty) {
if (!isCreditCard(valueCandidate)) return errorText;
}
return null;
};
}