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)

Skipping Incoming Ports

While the outgoing ports are necessary to invert the dependency between the application layer and the outgoing adapters (to make the dependencies point inward), we don't need the incoming ports for dependency inversion. We could decide to let the incoming adapters access our application services directly, without incoming ports in between, as shown in the following figure:

Figure 11.3: Without incoming ports, we lose clearly marked entry points to the domain logic

By removing the incoming ports, we have reduced a layer of abstraction between incoming adapters and the application layer. Removing layers of abstraction usually feels rather good.

The incoming ports, however, define the entry points into our application core. Once we remove them, we must know more about the internals of our application to find out which service method we can call to implement a certain use case. By maintaining dedicated incoming ports, we can identify the entry points...