Book Image

Get Your Hands Dirty on Clean Architecture

By : Tom Hombergs
Book Image

Get Your Hands Dirty on Clean Architecture

By: Tom Hombergs

Overview of this book

Building for maintainability is key to keeping development costs low and processes easy. The second edition of Get Your Hands Dirty on Clean Architecture is here to equip you with the essential skills and knowledge to build maintainable software. With this comprehensive guide, you’ll explore the drawbacks of conventional layered architecture and the advantages of domain-centric styles such as Robert C. Martin's Clean Architecture and Alistair Cockburn's Hexagonal Architecture. Then, you’ll dive into hands-on explanations on how to convert hexagonal architecture into actual code. You'll learn in detail about different mapping strategies between the layers of hexagonal architecture and discover how to assemble the architectural elements into an application. Additionally, you’ll understand how to enforce architecture boundaries, which shortcuts produce what types of technical debt, and how, sometimes, it is a good idea to willingly take on those debts. By the end of this second edition, you'll be armed with a deep understanding of the hexagonal architecture style and be ready to create maintainable web applications that save money and time.
Table of Contents (13 chapters)

Boundaries and Dependencies

Before we talk about different ways of enforcing architecture boundaries, let's discuss where the boundaries lie within our architecture and what "enforcing a boundary" actually means:

Figure 10.1: Enforcing architecture boundaries means enforcing that dependencies point in the right direction. Dashed arrows mark dependencies that are not allowed according to our architecture

The preceding figure shows how the elements of our hexagonal architecture might be distributed across four layers resembling the generic clean architecture approach introduced in Chapter 2, Inverting Dependencies.

The innermost layer contains domain entities. The application layer may access those domain entities to implement use cases within application services. Adapters access those services through incoming ports or are being accessed by those services through outgoing ports. Finally, the configuration layer contains factories that create adapter and service...