Book Image

Hands-On Domain-Driven Design with .NET Core

By : Alexey Zimarev
Book Image

Hands-On Domain-Driven Design with .NET Core

By: Alexey Zimarev

Overview of this book

Developers across the world are rapidly adopting DDD principles to deliver powerful results when writing software that deals with complex business requirements. This book will guide you in involving business stakeholders when choosing the software you are planning to build for them. By figuring out the temporal nature of behavior-driven domain models, you will be able to build leaner, more agile, and modular systems. You’ll begin by uncovering domain complexity and learn how to capture the behavioral aspects of the domain language. You will then learn about EventStorming and advance to creating a new project in .NET Core 2.1; you’ll also and write some code to transfer your events from sticky notes to C#. The book will show you how to use aggregates to handle commands and produce events. As you progress, you’ll get to grips with Bounded Contexts, Context Map, Event Sourcing, and CQRS. After translating domain models into executable C# code, you will create a frontend for your application using Vue.js. In addition to this, you’ll learn how to refactor your code and cover event versioning and migration essentials. By the end of this DDD book, you will have gained the confidence to implement the DDD approach in your organization and be able to explore new techniques that complement what you’ve learned from the book.
Table of Contents (14 chapters)

Handling commands

In the previous section, we created a simple web API and learned that the API is the edge of our application. The edge talks with the outside world and accepts requests via HTTP or another communication protocol. To execute these requests, we need an application service that works as an intermediary between edge components and the domain model. The application service is also responsible for persisting entities.

Going forward, we will learn more about handling commands and persistence. Also, we will discuss handling exceptions and checking whether incoming requests are valid.

The command handler pattern

There are several ways to handle commands in CQRS. One established pattern is to use command handlers....