Capturing payment; express checkout - paypal

Hi
I have paypal express checkout working on my site, when user buys something the transaction goes through and the merchant is able to capture payment by clicking on the capture button on the sandbox site. Problem is that I need 'capture status' returned to the site as I need to store it in database for future use, is there a way that paypal sends some notification whenever the payment is captured by the merchant.
Thanks

PayPal IPN: https://www.paypal.com/ipn
In short, include NOTIFYURL in your SetExpressCheckout and DoExpresscheckoutPayment call and you'll receive a POST on that URL when the transaction has been captured. Look for 'PAYMENTSTATUS', as that should read 'Complete'.
Don't forget to validate the POST by sending it back to https://www.paypal.com/cgi-bin/webscr?cmd=_notify-validate and checking for a VERIFIED / INVALID response.

Related

SetExpressCheckout callback

Is there any way I can be notified that someone has approved a payment through SetExpressCheckout, if they don't get redirected back to my website?
ie. After they approve the payment I would receive a callback or payment notification.
If so, how would I do it?
Thanks.
Users will always be redirected to your site when using Express Checkout. They have to because the payment isn't final until you call DoExpressCheckoutPayment which can't occur until after they've been redirected back to your site. Maybe I don't understand what you're asking here..??
In any case, take a look at IPN (Instant Payment Notification). It will POST transaction data to a listener script you have on your server so you can automate post-order processing in real-time. Again, though, no IPN would be triggered form SetExpressCheckout alone because no payment has actually been made at that point.

Paypal PhP api security issue

I was trying to use the express checkout php api. Everything is working well in the sandbox environment. My question is regarding security.
After payment the sample code redirects to GetExpressCheckout.php?token=...$PayerID=.....; But after clicking "confirm payment" in my site and logging in to paypal account (did not confirm payment in paypal); I directly opened the same page in another tab, and it showed payment successful (which is not the case). Is there a way to prevent this or am I missing some thing.
I'm not following exactly what you're trying to say here.
The process needs to be...
1) Call SetExpressCheckout to retrieve your token and redirect to PayPal accordingly.
2) PayPal will return the user back to your ReturnURL if they confirm payment, at which point you can call GetExpressCheckoutDetails (optionally) and DoExpressCheckoutPayment to finalize the payment.
Not until DECP is completed does any transaction actually take place. The success message you're seeing probably came from GetExpressCheckoutDetails, which does nothing more than retrieve the buyer/order info so that you can finalize the payment on your site.

Paypal NVP with IPN for confirmation - what ties them together

I am using PayPal with NVP API (using PHP) for express checkout. I am creating an invoice record in the database before redirecting the user to Paypal. In case the user doesn't return to my site after processing, I am using IPN to confirm the purchase and then update the invoice record that the payment is confirmed. I am still in the sandbox mode and trying to figure out how I will tie the transaction started with NVP to the confirmation I get with IPN.
I need to verify if the "PAYMENTREQUEST_n_INVNUM" sent in the NVP will come back as "invoice" in the IPN post.
It appears I cannot actually test this until I am live since the Sandbox IPN does not seem to be active with NVP initiated sandbox transactions - is this correct?
Thanks for your help.
You can test this in Sandbox. But if you're using "PayPal NVP", I assume you're using PayPal Express Checkout and calling the SetExpressCheckout and DoExpressCheckoutPayment API's.
If that's the case, you don't really need IPN, because a transaction will only be completed as soon as you call DoExpressCheckoutPayment.
In other words, buyers will always be redirected to the RETURNURL you specified in SetExpressCheckout, and the transaction is completed (or not) when you call DoExpressCheckoutPayment on this return page.
To get the invoice number, you could call GetExpressCheckoutDetails and supply the TOKEN you retrieved earlier (it's also appended to the GET of the RETURNURL).
Finally, check PAYMENTSTATUS=Completed in the DoExpressCheckoutPayment API response to see whether the transaction has completed or not.
Thank you Robert for the clarity on the process - especially useraction=commit.
I finally realized that I could turn on IPN in the Sandbox for my test seller and test NVP with IPN together. I was able to verify that PAYMENTREQUEST_0_INVNUM matches the 'INVOICE' parameter in the IPN POST.
I will use the custom field to pass customer email from my system in case they use a different email to log into paypal with, therefore allowing me to have email/invoice number pair for confirmation.

Not receiving money through Paypal Express Checkout API

I developed a small payment process that uses the Express Checkout API. I'm testing the code with my friend's account with $1. My payment process is redirecting to the live paypal site, he enters his information and pays, he is redirected to my confirmation thank you page, but I never receive funds. I've checked my API credentials in the code, and they are OK. I'm receiving a token and paypal payerid info on my confirmation screen. What could be the problem?
Thank you in advance.
See my answer in Why is DoExpressCheckoutPayment required for Paypal?
In order to use Express Checkout, you must call at least the following API calls:
1. SetExpressCheckout -- to set up the transaction.
2. DoExpressCheckoutPayment -- to finalize the transaction.
If you don't call DoExpressCheckoutPayment on the 'Thank you' page, the transaction is not completed. This is by design to allow for greater flexibility
Express Checkout is intended as a drop-in solution in your own checkout process. After Express Checkout redirects you back to your site, you're supposed to show an order confirmation where the buyer can review his/her final order details before initiating a button / link which initiates the final DoExpressCheckoutPayment API call. This is why DoExpressCheckoutPayment is required.

DNN and PayPal, how to sent email to customer after payment has been made

In my DNN website, using Paypal's Checkout button, when user has click the buy button and sent to Paypal. Make a payment and then redirect back to my site.
Question:
How can I get that customer email address (from Paypal) so that i can sent a conformation email to him/her from my DNN website?
thanks.
Two ways; you can either call the GetTransactionDetails API and supply the TRANSACTIONID as a parameter. 'EMAIL' will contain the buyer's (PayPal) email address.
Or you can use PayPal IPN to get notified through POST whenever a payment / action has been made.
GetTransactionDetails API doc is at https://cms.paypal.com/us/cgi-bin/?cmd=_render-content&content_ID=developer/e_howto_api_nvp_r_GetTransactionDetails
You can also have a look at TransactionSearch for past transactions.
In case you want to use IPN, just supply NOTIFYURL in your SetExpressCheckout and DoExpressCheckoutPayment call if you're using Express Checkout, or if you're using Website Payments Standard.
Remember to send the POST back to PayPal for validation at paypal.com/cgi-bin/webscr?cmd=_notify-validate and check for a VERIFIED / INVALID response.
Some sample code and docs for IPN is available at https://www.paypal.com/ipn/