CQRS with Event Sourcing sample app using Rails Event Store. See it live.

This application simulates a process of managing orders.

We start with a list of exiting products and customers (populated with seeds).

• Add/remove some of the existing products to the order
• Choose the customer
• Submit the order
  • after this you can't update the order items or customer
  • it generates the order number like "2021/03/20" (the last part is random(100))
• Look at the order
• Look at the history of events (in the Rails Event Store Browser)

Domains exist in directories at the root level of the Rails app.

The Ordering::Order aggregate manages the state machine of an order:

• draft
• submitted
• paid
• expired

After each successful change an appropriate event is published in the Order stream. This object is fully event sourced.

The Payments::Payment aggregate manages the following states:

• authorized
• captured
• released This object is fully event sourced.

There's only one read model - which helps us listing all the orders and individual order details.

It consists of 2 ActiveRecord classes: Order and OrderItem.

There's a process manager responsible for dealing with the process of expiring orders.

It takes the following events as the input:

• Ordering::OrderSubmitted
• Ordering::OrderExpired
• Ordering::OrderPaid
• Payments::PaymentAuthorized
• Payments::PaymentReleased

When certain conditions are met the process manager return a ReleasePayment command.