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)

The "No Mapping" Strategy

The first strategy is actually not mapping at all:

Figure 8.1: If the port interfaces use the domain model as the input and output model, we don't need to map between layers

The preceding figure shows the components that are relevant to the "Send Money" use case from our BuckPal example application.

In the web layer, the web controller calls the SendMoneyUseCase interface to execute the use case. This interface takes an Account object as an argument. This means that both the web layer and the application layer need access to the Account class – both are using the same model.

On the other side of the application, we have the same relationship between the persistence and application layers. Since all layers use the same model, we don't need to implement a mapping between them.

But what are the consequences of this design?

The web and persistence layers may have special requirements for their models. If our web layer exposes...