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 DateTime? date = DateTime.tryParse(valueCandidate);
  return date != null && date.isBefore(DateTime.now()) ? null : errorText;
}