Syrve POS API SDK

Payment screen (cash screen) allows modifications initiated by a plugin

[ v9preview3  v9  ]

Starting from V9Preview3, a plugin can edit the current order opened on the cash register via the API without receiving an EntityAlreadyInUseException :-)

Previously, in V7Preview5, the ability to edit an order opened on the editing screen at any time when no other operations are being performed was added (details).

To make changes to an order opened on the payment screen, the plugin needs to call the method TryEditCurrentPaymentScreen and pass a reference to a callback that syrveFront will invoke as soon as the opportunity arises. If there is no activity, this will happen immediately; if other operations are being performed, the callback will be invoked right after their completion. In any case, the TryEditCurrentPaymentScreen method will return control after the callback is invoked. If the callback throws an exception, it will propagate from TryEditCurrentPaymentScreen. In the event that another operation was being performed at the time of the TryEditCurrentPaymentScreen call, which eventually led to exiting the order payment screen, the callback cannot be invoked immediately or later, and the TryEditCurrentPaymentScreen method will generate an OperationCanceledException.

A progress bar is displayed while the callback is executing. The following will be passed to the callback:

The callback has a return value, which for most users should be null.

Example:

private void EditPayScreen()
{
    PluginContext.Operations.TryEditCurrentPaymentScreen(x =>
    {
        // In "Split by Amount" mode (currently unavailable to most users), we add a new guest to the order,
        // subtract 10 from the resulting sum of existing guests, aggregate them, and add to the new guest.
        if (x.context.PaymentSplitMode == PaymentSplitMode.SplitByPrice)
        {
            var guestsSums = new List<(Guid, decimal)>();
            var newGuest = x.os.AddOrderGuest($"Guest {x.context.PaymentSplitGuestInfos.Count + 1}", x.order, x.os.GetDefaultCredentials());

            var newGuestResultSum = 0m;
            foreach (var guestInfo in x.context.PaymentSplitGuestInfos)
            {
                if (guestInfo.ResultSum > 10)
                {
                    guestsSums.Add((guestInfo.GuestId.Value, guestInfo.ResultSum - 10));
                    newGuestResultSum += 10;
                }
                else
                {
                    guestsSums.Add((guestInfo.GuestId.Value, guestInfo.ResultSum));
                }
            }
            guestsSums.Add((newGuest.Id, newGuestResultSum));
            // Return the distribution of amounts by guests in "Split by Amount" mode.
            return guestsSums;
        }

        // In "Split by Dish" mode (currently unavailable to most users), we add a new dish to the last guest.
        if (x.context.PaymentSplitMode == PaymentSplitMode.SplitByDish)
        {
            var product = x.os.GetActiveProducts().Single(p => p.Name == "Flyer dish");
            x.os.AddOrderProductItem(1m, product, x.order, x.order.Guests.Last(), null, x.os.GetDefaultCredentials());
            // Return null, as sum distribution by guests is unavailable in "Split by Dish" mode.
            return null;
        }

        // In "Whole Order" mode (default), we add a VISA payment type to the order for the full amount.
        if (x.context.PaymentSplitMode == PaymentSplitMode.WholeOrder)
        {
            x.os.AddPaymentItem(x.context.PaymentSplitGuestInfos.Single().ResultSum, null, x.os.GetPaymentTypes().First(p => p.Name.ToUpper() == "VISA"), x.order, x.os.GetDefaultCredentials());
            // Return null, as sum distribution by guests is unavailable in "Whole Order" mode.
            return null;
        }

        throw new InvalidEnumArgumentException(nameof(x.context.PaymentSplitMode), (int)x.context.PaymentSplitMode, typeof(PaymentSplitMode));
    });
}