Book Image

Domain-Driven Design in PHP

By : Keyvan Akbary, Carlos Buenosvinos, Christian Soronellas
Book Image

Domain-Driven Design in PHP

By: Keyvan Akbary, Carlos Buenosvinos, Christian Soronellas

Overview of this book

Domain-Driven Design (DDD) has arrived in the PHP community, but for all the talk, there is very little real code. Without being in a training session and with no PHP real examples, learning DDD can be challenging. This book changes all that. It details how to implement tactical DDD patterns and gives full examples of topics such as integrating Bounded Contexts with REST, and DDD messaging strategies. In this book, the authors show you, with tons of details and examples, how to properly design Entities, Value Objects, Services, Domain Events, Aggregates, Factories, Repositories, Services, and Application Services with PHP. They show how to apply Hexagonal Architecture within your application whether you use an open source framework or your own.
Table of Contents (24 chapters)
Title Page
Credits
Foreword
About the Authors
Acknowledgments
www.PacktPub.com
Customer Feedback
Dedication
Preface
14
Bibliography
15
The End

Wrap-Up


As we've seen, Services represent operations inside our system, and we can differentiate between three versions of them:

  • Application Services: Help coordinate requests from the outside world into the Domain. These Services should not contain Domain logic. Transactions are handled in the application level; wrapping your services inside transnational decorators will make your code transaction agnostic.
  • Domain Services: Operate with Domain concepts only, which are expressed by the Ubiquitous Language. Remember to postpone implementation details and think of behavior first, as abuse of Domain Services will lead to Anemic Domain Models and bad Object-Oriented Design.
  • Infrastructure Services: Operate over Infrastructure, doing things like sending emails or logging information.

Our most important recommendation is that you should consider all your options before deciding on creating a Domain Service. First try to move your business logic inside an Entity or Value. Check with some workmates...