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)

Organizing by Feature

Let's try to address some of the issues of the "organize by layer" approach.

The next approach is to organize our code by feature:

Figure 3.2: When organizing code by feature, the underlying architecture tends not to be apparent

In essence, we have put all the code related to accounts into the high-level account package. We have also removed the layer packages.

Each new group of features will get a new high-level package next to account and we can enforce package boundaries between the features by using package-private visibility for the classes that should not be accessed from the outside.

The package boundaries, combined with package-private visibility, enable us to avoid unwanted dependencies between features.

We have also renamed AccountService to SendMoneyService to narrow its responsibility (we actually could have done that in the package-by-layer approach, too). We can now see that the code implements the "Send Money" use case...