Hi,
If I put a PayPal.Me donate button in a Desktop.HTMLViewer, can I retrieve the payment status (eg, true/false) in my app? to possibly generate a validation code.
Thanks
From what I see, Paypal.Me seems to be a subset of Paypal.
Paypal has a system named IPN (Instant Payment Notification) when Paypal will post a message to a listener web app, to inform it that a transaction took place, together with the status of it.
I use this to automatically deliver software to my customers.
You could have an IPN listener set on a web host, which logs the transactions, so the desktop app can fetch that and check the transaction completeness.
Examples of listeners code are posted on github:
Thanks.
Seems to me to be quite complex to install, right?
So I have to go through web hosting, which JavaScript or PHP code do you use?
I used Perl a while ago, then I used Php, and today Xojo Cloud with a Xojo Web app.
For a Php script, hosting is extremely affordable these days. See hostgator.com or namecheap.com.
That said, you need to evaluate the interest of the IPN versus very simply generating the validation code when you receive email notice of payment from Paypal. Sure, it will take longer when you are not in front of your computer, but in terms of engineering, it is way simpler.
Say you sell one or two licenses per week, the IPN is probably overkill.
Yes, you’re right. In my case, it is better to generate a validation code on receipt of the payment email. but then, how to customize this code so that it is not exchanged with other users?
There is no bullet proof method. You will never be able to prevent buyers from passing their code to others. It takes no time to find license codes for Microsoft or Adobe on the web.
In a similar scheme, I required users to enter their name, as used to buy from Paypal. Then from that name and the time of purchase, I generated a code by hash or other encryption.
The app verifies that the name entered matches the code with the same kind of algorithm used to generate the code. If so, it unlocks.
The fact that the buyer needs to enter his full name can somewhat mitigate the possibility that he may post the app on the Internet.