Hi,

I don't know exactly what you mean by a "bespoke buy now button". You cannot add a plain html button with a form in the html content feature if that is what you mean for the same reason you cannot do it with PayPal, you must use an actual asp.net button that posts the existing form rather than add an html form. Obviously the html content feature could not generate the md5 secret for you but it also cannot have an html form element in the content.

If you are doing actual custom development developing custom features in Visual Studio you can do it the same way we do it in all of our ecommerce features. We have a WorldPayPurchaseButton included in mojoPortal core that can be used in custom development the same as it is used in all of our ecommerce features and it generates the md5 hash and signature field html based on properties set on the control. Or if that button control doesn't meet your needs you could implement your own using similar code. There is nothing that limits what can be done in bespoke custom development.

Hope that helps,

Joe

Glad that helps, if you want to see example code where that button is configured see the SetupWorldPay method in the Checkout page for webstore.

Note that what we set as the cartid on the button is not the actual cart guid but the guid of the worldpay log. The cart is serialized as a string and stored in the log and then reconstituted from the log if the transaction is completed. This prevents manipulation of the order. For example if we used the actual cart guid then the user could use 2 browser tabs and after they are posted over to WorldPay they could add items to the cart from the other browser tab and try to get more than they actually purchased at WorldPay. By serializing the current state of the cart just before sending them to WorldPay we can be sure we are re-constituting it just as it was. Each time the cart is modified we create a new log so the guid would not match if the user tries to engineer some manipulation with 2 browser windows. We use a similar technique in all cases where the user completes payment on another site like PayPal, Google, or WorldPay.