This document provides an overview of using Google Checkout with Ruby on Rails. It discusses setting up merchant accounts in the sandbox and production environments, using the HTML and XML APIs to create purchase requests, and handling purchase notifications to update orders in the application. A simple example is shown to create a purchase, register for notifications, and update the order status based on financial changes reported in the notifications. More advanced features and additional resources are also mentioned.

1. Google
Checkout with
Ruby on Rails

2. Software Engineer, Consultant, Trainer
http://simplabs.com
Open Source
http://github.com/marcoow
http://github.com/simplabs
Marco Otte-Witte

3. USA/UK only!

4. Merchant Accounts
• Production Merchant Account
https://checkout.google.com/sell
• Sandbox Merchant Accournt
http://sandbox.google.com/checkout/sell
• => Merchant ID, Merchant Key

5. APIs
• HTML and XML APIs
• Notification APIs
• Example uses HTML API via HTTParty

6. Very(!) simple example
• Create Purchase with Google Checkout
• When Google Checkout confirms the
payment handle the Purchase in the app

7. Create Purchase
• Post an HTML Form to Google
• or create via HTML API:
post("/requestForm/Merchant/#{merchant_id}", :body => {
:_type => 'checkout-shopping-cart',
:'shopping-cart.items.item-1.item-name' => product.name,
:'shopping-cart.items.item-1.item-description' => product.description,
:'shopping-cart.items.item-1.quantity' => 1,
:'shopping-cart.items.item-1.unit-price' => price,
:'shopping-cart.items.item-1.unit-price.currency' => currency
})
• => returns serial-number to later identify
the purchase

8. Create Purchase

9. Notifications
• Register for Notifications:
(need SSH tunnel for local development)

10. Complete Purchase
• State Change Notifications:
def callback
type = params[:'_type']
serial_number = params[:'serial-number']
if type == 'order-state-change-notification'
order_state = params[:'new-financial-order-state']
purchase = GoogleCheckoutPurchase.find_by_serial_number(serial_number)
case order_state.try(:downcase)
when 'charged'
purchase.book!
when 'payment_declined', 'cancelled', 'cancelled_by_google'
purchase.fail!
end
end
render :text => "serial-number=#{serial_number}", :status => :ok
rescue
head :internal_server_error
end

11. A lot more can
be done!

12. Resources
• http://code.google.com/intl/de-DE/apis/checkout/
• https://rubygems.org/gems/google4r-checkout

13. Q&A