public IList <MessageString> ValidateTrackingNumber()
{
TrackingNumber = StringHelper.TrimWhitespace(TrackingNumber);
if (String.IsNullOrEmpty(TrackingNumber))
{
return new List <MessageString>()
{
MessageString.Error("Tracking number is empty")
}
}
;
if (Carrier == ShippingServiceUtils.USPSCarrier)
{
if (TrackingNumber.Length != 22)
{
return new List <MessageString>()
{
MessageString.Error("Invalid tracking number format")
}
}
;
var checkDigitResult = TrackingHelper.GetCheckDigit(TrackingNumber);
if (checkDigitResult.IsFail)
{
return new List <MessageString>()
{
MessageString.Error(checkDigitResult.Message)
}
}
;
if (checkDigitResult.Data.ToString()[0] != TrackingNumber.Last())
{
return new List <MessageString>()
{
MessageString.Error("Invalid check sum. Expected: " + checkDigitResult.Data)
}
}
;
}
return(new List <MessageString>());
}
