We want to create a new payment method in Magento which uses an iframe to display our payment gateway's credit card form (we are not PCI-compliant). We've found this so far to be very challenging. We have only been able to implement the "redirect" method, wherein the checkout page redirects to a brand new page hosted in our payment gateway's server that displays the credit card form. We would like to have this appear in an iframe in the checkout page instead.
Which built-in payment methods in Magento (or extensions in magentocommerce) offer an iframe option? We guess if we study the code of those payment methods, we could implement our own.
We've tried Ebizmarts Sage Pay (their magentocommerce page indicates they support iframe), but the code is too complex for us for now. We were hoping there are simpler ones out there.
By the way, we're using EE 1.13.