notInFn method
check is the value is not in values
Implementation
FieldValidator<T, R> notInFn(ValueGetter<List<R>> values,
[MessageCallBack<R>? message]) {
return next((messages, value) {
var val = values();
if (val.contains(value)) {
return message?.call(messages, value) ?? messages.isNotIn(val);
}
return null;
});
}