required<T> static method
Implementation
static FormFieldValidator<T> required<T>({String? errorText}) {
return (T? valueCandidate) {
if (valueCandidate == null ||
(valueCandidate is String && valueCandidate.trim().isEmpty) ||
(valueCandidate is Iterable && valueCandidate.isEmpty) ||
(valueCandidate is Map && valueCandidate.isEmpty)) {
return errorText ?? BasicFormValidatorMessageError().required;
}
return null;
};
}