isValidDateString method
isValidDateString returns an error if the date is not in the correct format.
Returns a formatted dateString according to the designated format if is a valid date string.
format defaults to "M-d-yyyy", eg. "1-12-2022";
Implementation
String? isValidDateString({String? format = "M-d-yyyy"}) {
final result = DateTime.tryParse(this!);
if (result == null) {
return 'Invalid date format.';
}
final _formattedDate = DateFormat(format).format(result.toLocal());
return _formattedDate;
}