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


A Repository is a mechanism that acts as a storage location. The difference between a DAO and a Repository is that a DAO follows a database-first approach, decreasing cohesion with many low-level methods to query the database. Depending on the underlying persistence mechanics, we've seen different Repository approaches:

  • Collection-oriented Repositories tend to be purer to the Domain model, even if they persist Entities. From the client's point of view, a collection-oriented Repository looks like a collection (Set). There's no need for explicit persistence calls on Entity updates, as the Repository tracks changes on the objects. We explored how to use Doctrine as the underlying persistence mechanism for this type of Repository.
  • Persistence-oriented Repositories require explicit persistence calls, as they don't track object changes. We explored Redis and plain SQL implementations.

Along the way, we discovered Specifications as a pattern that helps us query the database without sacrificing...