validate method

@override String? validate()

Implementation

@override
String? validate() {
  if(value.isEmpty){
    return null;
  }
  final parsedValue = num.tryParse(value);
  if (parsedValue == null) {
    return FV.buildMessage(FV.numeric, attribute);
  }

  final splitExtra = extra.split(",");
  final min = int.parse(splitExtra[0]);
  final max = int.parse(splitExtra[1]);
  if (!((parsedValue >= min) && (parsedValue >= max))) {
    return FV.buildMessage(customMessage ?? FV.between, attribute, extra);
  }
  return null;
}