Real-Time Phoenix

Wrapping Up

We’ve built a fully functioning shopping cart, using the tools we’ve covered throughout this book. We had to flex all of our Channel and real-time system skills to build this relatively complex feature. We used the basic handle_in and handle_out features in Phoenix Channels to take client commands and send data to the clients. We leveraged PubSub with dynamic subscriptions to keep track of when an item goes out-of-stock. We made our system work across distributed servers by using an order of operations in our inventory updates that provides our shoppers with a consistent view of their cart.

Acceptance tests, whether manual or automated, are extremely useful in finding bugs in the code that we write. We performed two complex acceptance ...