The example order management system server web app processes orders in a single function, payment (described in Chapter 4, Payment Processing Workflow), which clients execute through an HTTP POST request to the http://red:12345/payment URI.
First, the function attempts to charge the customer card. If the charge is successful, the function adds a record to the Order collection using the order information that the client provided. When done, the function returns information about the payment transaction and the new order (if it was created) to the client.
Refer to the Process Phase section in Chapter 4, Payment Processing Workflow, for details about the implementation of the payment function.
