In a previous post I tried to give an introduction on how to get started with PayPal Payment Data Transfers (PDT). PDT is very handy in several cases, but you can’t always rely on it since it requires the user to return to your page after doing the payment. That will often happen, but it’s not guaranteed to happen. If you for example want to mark an order in your system as paid or something like that, you most likely want to use PayPal Instant Payment Notifications (IPN) in addition to PDT.
Instant Payment Notification (IPN) is a message service that notifies you of events related to PayPal transactions. You can use it to automate back-office and administrative functions, such as fulfilling orders, tracking customers, and providing status and other information related to a transaction. — PayPal
Once again the documentation, tutorials and code samples I found on this was a bit all over the place. Sort of messy and outdated. So, once again I decided to do my own thing and just follow the steps required and implement them myself. And since the tutorial on PDT turned out to be a bit of a success, I decided to share this too. Hopefully it can make the lives of fellow developers easier
Say you have a PayPal “Buy Now”-button on your website and you have assigned return URLs like
http://example.com/order?canceled. You can then welcome the user back after a successful payment. But what if you wanted to say something more interesting than just “hey, welcome back” when they click on that “Return to Merchant”-button? And can you know if the order was actually done or canceled? Maybe you’d like to log the transaction in your database and mark a payment as complete or something like that too? In that case you sure can’t trust a simple flag in the address bar…
Payment Data Transfer (PDT) is a secure method to retrieve the details about a PayPal transaction so that you can display them to your customer. It is used in combination with Website Payments Standard, so that after a customer returns to your website after paying on the PayPal site, they can instantly view a confirmation message with the details of the transaction. — PayPal
I’ve tried to figure out how to use PDT and found that most samples and classes to build from are usually quite ugly, old or outdated. I didn’t find them too useful anyways… So, therefore, I’ve tried to do my own thing based on the documentation found on the PayPal Developer websites. (Seriously, how many versions of documents and developer websites do they have anyways? It’s like a complete jungle…)
Since the documentation was a bit of a mess, I thought I make a small tutorial on the steps needed to get started. That way I can learn it better myself and hopefully help some other poor souls that need to figure this stuff out as well. Please provide feedback if you have any! Would love to make this page nicer and clearer if possible
I need to figure out how to use the PayPal IPN thing. And for experimentation with PayPal things, you should of course not use live accounts. You could, but it’s probably not the best idea. Luckily, PayPal has something they call a Sandbox where you can create and manage fake PayPal accounts that you can experiment with.
It’s not very difficult to get started, but there was a couple of points that wasn’t totally clear to me at first. Therefore I thought I could document it here.