// Add to the waitlist
private void btnAddToWaitlist(object sender, EventArgs e)
{
lblMessages.Text = ""; // clear lables of error before checking.
// must check IF any seat is empty.
try
{
// if flight is full, throw exception
if (!AirplaneService.IsFull())
{
throw new ConstraintException();
}
var attempt = WaitlistService.AddToWaitlist(txtName.Text);
if (!attempt)
{
lblMessages.Text += "Waitlist is full!\r\n";
}
lblMessages.Text += $"Added {txtName.Text} to the Waitlist\r\n";
btnShowWaitingList(sender, e); // update dialog status
ResetSelection();
}
catch (ConstraintException) // full flight
{
lblMessages.Text += "Waitlist is only available after all\n\r seats are assigned.\r\n";
}
catch (NullReferenceException) // empty name
{
lblMessages.Text += "Name must not be empty or white spaced\r\n";
}
}
