Question

Sorry for the very basic nature of the question, but I’ve been searching for two days and I’m still not sure how to do this.

I’ve got a paypal cart/store set up. How do I leverage either paypal IPN or a third party service to identify one specific item of the three items I have for sale, and send me a notification that a copy has been purchased, and then update a counter on my original website?

Again, just suggestions or a guideline would be greatly appreciated – even to point me in the right direction. Thank you.

Answer 1

A basic guideline for you:

• have a sandbox account (I assume you already do)
• create there a seller and buyer account
• set IPN setting for seller account to your testing URL (where you will be checking for certain data returned)
• for the URL mentioned above create a php file with IPN validator
• and go here https://cms.paypal.com/us/cgi-bin/?cmd=_render-content&content_ID=developer/e_howto_html_IPNandPDTVariables#id08CTB0S055Z to check variables you will be searching for.

I assume you would need to pick num_cart_items and loop throug possible item_nameX variables returned.

You don’t need to code anything to validate IPN, use some of these classes:
http://www.micahcarrick.com/php-paypal-ipn-integration-class.html
http://www.phpclasses.org/package/2249-PHP-Process-Paypal-payment-interactions.html