I made a simple app to demonstrate how off-site payments for Worldpay and Rails/Activemerchant can work together.
Demo Rails App-
https://github.com/daemonsy/Worldpay-Rails--Off-Site--Integration-Example
For World Pay hosted payment, basically a post to their payment URL is required. Add test- to secure.worldpay.com for testing mode. WP requires amount, currency, installation ID and cartId to render the page to the customer.
<form action="https://test-secure.worldpay.com/wcc/purchase" method=POST>
<!-- This next line contains the testMode parameter - it specifies that the submission is a test submission -->
<input type="hidden" name="testMode" value="100">
<!-- This next line contains a mandatory parameter. Put your Installation ID inside the quotes after value= -->
<input type="hidden" name="instId" value="Your installation ID ">
<!-- Another mandatory parameter. Put your own reference identifier for the item purchased inside the quotes after value= -->
<input type="hidden" name="cartId" value="Your ID for the product ">
<!-- Another mandatory parameter. Put the total cost of the item inside the quotes after value= -->
<input type="hidden" name="amount" value="The cost of the product ">
<!-- Another mandatory parameter. Put the code for the purchase currency inside the quotes after value= -->
<input type="hidden" name="currency" value="currency code e.g. GBP, USD ">
<!-- This creates the button. When it is selected in the browser, the form submits the purchase details to us. -->
<input type=submit value=" Buy This ">
Source: http://www.worldpay.com/support/kb/bg/htmlredirect/rhtml.html
This creates a simple button that carries your order to World Pay where the customer will enter credit card details and complete the purchase. I've embedded the above code in the show page of an orders controller. e,g, <input type="hidden" name="amount" value="<%[email protected]"%>>. So you can click buy this after submitting the order. There are many ways to achieve a POST to World Pay.
After which, World Pay can show a shopper response page, send you payment response etc. For payment response to work, you can setup the payment response callback URL to one of your controllers. e.g. =>http://mysite.com/payment-backend
This will be a POST request so you have to setup your controller to handle it. This is where Activemerchant kicks in. For example,
class BackendsController < ApplicationController
include ActiveMerchant::Billing::Integrations
protect_from_forgery :except=>[:worldpay_return]
#in routes => match '/payment-backend'=>'backends#worldpay_return'
def worldpay_return
notification = WorldPay::Notification.new(request.raw_post)
order = Order.find(notification.item_id)
if notification.acknowledge
begin
if notification.complete?
order.status = 'success'
end
rescue
order.status = "failed"
raise
ensure
order.save
end
end
render :text =>"Order status for #{order.id} is #{order.status}"
end
end
So the Notification object will read the params in request.raw_post and set them up the an object where you can query. I found the active merchant docs useful in telling what return params are mapped by it.
Note that this controller is a very crude example. World Pay provides a few methods for you to validate the response and this is supported by Active Merchant.
ActiveMerchant Docs on WorldPay::Notifications
http://rdoc.info/github/Shopify/active_merchant/master/ActiveMerchant/Billing/Integrations/WorldPay
World Pay Payment Response Docs
http://www.worldpay.com/support/kb/bg/paymentresponse/payment_response.html
POSTto a worldpay URL? Like the Paypal button API. – Munda