User Checked Out (v1.0.0)

Represents an integration event when a user has completed the checkout process

Event Checkout Flow Order Initiation

Overview

The UserCheckedOutIntegrationEvent is a critical integration event that signals the completion of a customer’s checkout process in the BookWorm e-commerce system. This event serves as the primary trigger for initiating the order processing workflow across multiple services, particularly the Finance service which orchestrates the order state machine.

Architecture

Event Structure

The event contains the following key properties:

PropertyTypeDescription
OrderIdGuidUnique identifier for the newly created order
BasketIdGuidIdentifier of the basket being converted to an order
Emailstring?Customer’s email address (optional) for notifications and order association
TotalMoneydecimalTotal monetary value of the order

Technical Implementation

The UserCheckedOutIntegrationEvent is implemented as a simple record in C#:

Terminal window
public sealed record UserCheckedOutIntegrationEvent(
    Guid OrderId,
    Guid BasketId,
    string? Email,
    decimal TotalMoney
) : IntegrationEvent;

Workflow Context

This event plays a pivotal role in the order processing workflow:

  1. It is published by the Ordering service when a user completes checkout
  2. The Finance service receives this event and initiates the order state machine
  3. The event triggers the transition from basket to order in the system
  4. It serves as the correlation identifier for the entire order processing saga

Cross-Service Communication

This event facilitates communication between several bounded contexts:

  • Ordering → Finance: Initiates the order processing saga
  • Finance → Basket: Signals that the basket should be marked as processed

Business Impact

From a business perspective, this event represents a critical moment in the customer journey:

  • Conversion of a shopping intent (basket) to a purchase commitment (order)
  • Beginning of the fulfillment process
  • Opportunity for order confirmation communications
  • Point of financial transaction initiation