OpenACS Paypal Support package

paypal-support provides a convenient way to handle paypal IPN (Instant Payment Notifications). IPN in a nutshell is paypal POSTing all the details of a transaction to a pre-agreed url on your server. To ensure it's validity, you then post that back to a PayPal url which either verifies or rejects it.

My code currently supports only buy now links, which are suitable for my purposes as I just want to charge a single calculated amount at a time.

Your package would do the following:

1) Implement a tcl callback(s) that you want to run when Paypal has correctly notified you of a payment
2) Use the tcl API to generate the Buy Now link(s) (one of the arguments that you pass to the api is later used to determine which tcl callback to call)

When Paypal sends it's notification, the package will v