I have been building a shop for a client who has the Barclays ePDQ Merchant Account. They have been wanting to integrate this within their shop but trying to figure out creating a module is a bit of a mine field.
What I am after is a full payment module where users select to pay via Debit or Credit Card, then be transferred to Barclays secure site where the order number and amount is charged, users fill out their card details, pay then be returned to the shop's order complete page.
When drafting up a module like this, what would I need? How many different files would I need and what do I use to transfer the order amount and number to this page?