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)

Responsibilities of a web adapter

What does a web adapter actually do? Let’s say we want to provide a REST API for our BuckPal application. Where do the responsibilities of the web adapter start and where do they end?

A web adapter usually does these things:

  1. Maps the incoming HTTP request to objects.
  2. Performs authorization checks.
  3. Validates the input.
  4. Maps the request objects to the input model of the use case.
  5. Calls the use case.
  6. Maps the output of the use case back to HTTP.
  7. Returns the HTTP response.

First of all, a web adapter must listen to HTTP requests that match certain criteria such as a URL path, HTTP method, and content type. The parameters and the content of a matching HTTP request must then be deserialized into objects we can work with.

Commonly, a web adapter then does an authentication and authorization check and returns an error if it fails.

The state of the incoming objects can then be validated. But haven’...