We have to set up an Drupal 7 e-commerce site with Commerce module (Kickstart) that accepts payments via an off-site payment gateway. For which we are developing a commerce payment method that will accept payments from the payment gateway.
Now, We are stuck at this step where this page is shown to a user:
example.com/store/checkout/[transaction id]/review
After selecting the payment method (that we developed) on the above review page, the page redirects to the payment gateway site. The Payment gateway site, after a payment attempt, sends the payment status to a response page via POST method.
Now, we don't know where to 'catch' the post data sent by the payment gateway in the payment method module.
Also, after the POST data is processed, how to update the order/transaction
status in the database and show success/failure message to the user.
Any help would be appreciated.