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) {
  int valueLength = 0;

  if (valueCandidate is String) valueLength = valueCandidate.length;
  if (valueCandidate is Iterable) valueLength = valueCandidate.length;
  if (valueCandidate is Map) valueLength = valueCandidate.length;

  return valueLength != length && (!allowEmpty || valueLength > 0)
      ? errorText
      : null;
}