PAYPAL IPN problem

Question

It's not a problem but i don't know how to do this; let's say that I have a sign up form with some fields: username, password, email, as you know the user clicks on the BUY BUTTON and pay's up.

Well, how can I know the username that just made the payment, I mean how can I link those two things together, one idea it's to use the email address, but mose of the people sign up with different email addresses, mabe they have a different paypal address...you know...I need this information because I need a way to activate the account.

And I also need to know, if the user canceled a subscription will paypal post a message to my IPN link?

I'm doing this for the first time, any help it's appreciated!

Answer 1

I suggest you use the following PHP script for easy integration with PayPal's service (assuming you're using PHP): http://www.micahcarrick.com/04-19-2005/php-paypal-ipn-integration-class.html

If you do, the e-mail you will be looking for will be supplied in

$paypal->ipn_data['payer_email']

(again, assuming that $paypal is your object of the paypal_class class)

Obviously you have to follow the setup steps first. I suggest using the example script. It is really easy to do - in only four steps.

Answer 2

I suggest you read the official paypal documentation about IPN and recurring payments.

PayPal issues a IPN for every event that occurs to the user subscription, for example:

subscr_signup subscr_eot subscr_cancel subscr_failed

About the parameter, you can use a parameter named "custom" to pass a value, for example the user id or email, and that parameter will be sent you in every IPN.

Answer 3

Here are implementations of the PayPal IPN in both C# and VB:

http://www.xdevsoftware.com/PPIPNDesc.aspx

Here's an account of how I incorporated it into a PayPal subscriptions scenario:

http://www.codersbarn.com/post/2008/07/10/ASPNET-PayPal-Subscriptions-IPN.aspx