validateValue method

  1. @override
String? validateValue(
  1. T 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(T valueCandidate) {
  final num? value;

  if (valueCandidate is String) {
    value = num.tryParse(valueCandidate);
  } else if (valueCandidate is num) {
    value = valueCandidate;
  } else {
    return errorText;
  }

  if (value == null || (value < min || value > max)) {
    return errorText;
  }

  return null;
}