I'll be precise, i have been trying to add a custom gateway to bigcommerce, i have been somewhat successful till now, now i am stuck on bypassing the checkout page, i am unable to add additional option in checkout payment options, i'm able to do it using javascript, but then order is not being processed, and second thing, even if i am able to add option, and redirect user using javascript, how am i suppose to empty the cart once user has returned to the site?
I'm completely stuck here, any help or pointing to the right direction would be greatly appreciated.
For anyone who wish to achieve the same as i needed to, here is i went about it, i didn't touch the actual flow of the order and checkout, what i did, i renamed one of the offline payment method as the third-party gateway i wanted to integrate, then after checkout, user lands of thank-you page, on thank-you page, i embedded my script, which picked up order-id from thank-you page, and checked the payment method that was used during checkout, if it matches the one i required, then i redirected user to external url ( additional domain on another hosting ), where user and order details were fetched using order_id ( which i sent via ajax ) and the payment was processed, and in the end, user is redirected back to the bigcommerce store.
Things that you will need
It is kind of a complicated process, but once you get the hang of it, it becomes pretty simple after that.