Book Image

Get Your Hands Dirty on Clean Architecture - Second Edition

By : Tom Hombergs
4 (1)
Book Image

Get Your Hands Dirty on Clean Architecture - Second Edition

4 (1)
By: Tom Hombergs

Overview of this book

Building for maintainability is key to keep development costs low (and developers happy). 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. Building upon the success of the first edition, this comprehensive guide explores the drawbacks of conventional layered architecture and highlights the advantages of domain-centric styles such as Robert C. Martin's Clean Architecture and Alistair Cockburn's Hexagonal Architecture. Then, the book dives into hands-on chapters that show you how to manifest a Hexagonal Architecture in actual code. You'll learn in detail about different mapping strategies between the layers of a Hexagonal Architecture and see how to assemble the architecture elements into an application. The later chapters demonstrate how to enforce architecture boundaries, what 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. Whether you're a seasoned developer or a newcomer to the field, "Get Your Hands Dirty on Clean Architecture" will empower you to take your software architecture skills to new heights and build applications that stand the test of time.
Table of Contents (18 chapters)

Organizing By Layer

The first approach to organizing our code is by layer. We might organize the code like this:

For each of our layers – web, domain, and persistence – we have a dedicated package. As discussed in Chapter 2, What’s Wrong with Layers?, simple layers may not be the best structure for our code for several reasons, so we have already applied the Dependency Inversion Principle here, only allowing dependencies toward the domain code in the domain package. We did this by introducing the AccountRepository interface in the domain package and implementing it in the persistence package.

We can find at least three reasons why this package structure is suboptimal, however:

  • First, we have no package boundary between functional slices or features of our application. If we add a feature for managing users, we’ll add a UserController to the web package; a UserService, UserRepository, and User to the domain package; and...