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)

The “Full” mapping strategy

Another mapping strategy is what I call the “Full” mapping strategy, as outlined in Figure 9.3.

Figure 9.3 – With each operation requiring its own model, the web adapter and application layer each map their model into the model expected by the operation they want to execute

Figure 9.3 – With each operation requiring its own model, the web adapter and application layer each map their model into the model expected by the operation they want to execute

This mapping strategy introduces a separate input and output model per operation. Instead of using the domain model to communicate across layer boundaries, we use a model specific to each operation, such as SendMoneyCommand, which acts as an input model to the SendMoneyUseCase port in the figure. We can call those models “commands,” “requests,” or similar.

The web layer is responsible for mapping its input into the command object of the application layer. Such a command makes the interface to the application layer very explicit, with little room for interpretation. Each use case has its own...