public IEnumerable <ValidationResult> Validate(ValidationContext validationContext)
{
if (!IsCreditCardValid(CreditCardNumber))
{
yield return(new ValidationResult("Credit card number invalid"));
}
if (!string.IsNullOrEmpty(ExpiryDate))
{
var dateDigits = ExpiryDate.Replace("/", "");
if (dateDigits.Length == 4 && ValidationHelper.IsNumeric(dateDigits))
{
var month = int.Parse(dateDigits.Substring(0, 2));
var year = int.Parse("20" + dateDigits.Substring(2, 2));
if (month >= 1 && month <= 12 && year >= 2000 && year <= 2099)
{
// Set the exp date to the last day of month
var expDate = new DateTime(year, month, DateTime.DaysInMonth(year, month));
if (expDate < DateTime.Today)
{
yield return(new ValidationResult("Credit card expired"));
}
}
else
{
yield return(new ValidationResult("Expiry date invalid"));
}
}
else
{
yield return(new ValidationResult("Expiry date invalid"));
}
}
yield return(ValidationResult.Success);
}