hasLengthFn method

FieldValidator<String?, String?> hasLengthFn(
  1. ValueGetter<int> length, [
  2. MessageCallBack<String>? message
])

check is the value has length of length

Implementation

FieldValidator<String?, String?> hasLengthFn(ValueGetter<int> length,
    [MessageCallBack<String>? message]) {
  return next((messages, value) {
    var len = length();
    if (value != null && value.length != len) {
      return message?.call(messages, value) ?? messages.hasLength(len);
    }
    return null;
  });
}