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)

Using domain entities as the input or output model

If we have an Account domain entity and an incoming port, SendMoneyUseCase, we might be tempted to use the entity as the input and/or output model of the incoming port, as Figure 11.2 shows.

Figure 11.2 – Using a domain entity as the input or output model of a use case couples the domain entity to the use case

Figure 11.2 – Using a domain entity as the input or output model of a use case couples the domain entity to the use case

The incoming port has a dependency on the domain entity. The consequence of this is that we’ve added another reason for the Account entity to change.

Wait, the Account entity doesn’t have a dependency on the SendMoneyUseCase incoming port (it’s the other way around), so how can the incoming port be a reason to change for the entity?

Say we need some information about an account in the use case that is not currently available in the Account entity. This information is ultimately not to be stored in the Account entity, however, but in a different domain or bounded...