Question

I’m trying to add a payment method to working website that is using a wordpress auction plugin. The output should be that for every bid made, the user MUST pay a certain fee.

The question is: how to create a function, which:

1. receives the information
2. send the user to an external payment page
3. receive the answer from the payment page (can take some time because the users manually enter the information.
4. save the information to the database.

the 2nd and 3rd stages are a problem for me.

Answer 1

You can’t do it because a PHP script execution typically runs only during one request. It’s not possible to forward the user, suspend the execution of the script, and then continue with the same script.

A solution typically involves:

• Saving state before forwarding (typically with a session)
• Forward to external payment page
• The payment page must now forward to another page of yours where you can continue to process the request. Typically the external payment page can be parameterized with your callback URL and the forward back to your site will include information that will allow you to make a further query to the payment site to obtain the result of payment (failed/success).
• Your callback page retrieves the state it’s saved, the payment result, and does the rest.