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)

What about Read-Only Use Cases?

Previously, we have discussed how we might implement a use case that modifies the state of our model. How do we go about implementing read-only cases?

Let's assume the UI needs to display the balance of an account. Do we create a specific use case implementation for this?

It's awkward to talk of use cases for read-only operations like this one. Sure, in the UI, the requested data is needed to implement a certain use case we might call "View Account Balance." If this is considered a use case in the context of the project, by all means we should implement it just like the other ones.

From the viewpoint of the application core, however, this is a simple query for data. So, if it's not considered a use case in the context of the project, we can implement it as a query to set it apart from the real use cases.

One way of doing this within our architecture style is to create a dedicated incoming port for the query and implement it in a &quot...