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

Event Sourcing


CQRS is a powerful and flexible architecture. There's an added benefit to it in regard to gathering and saving the Domain Events (which occurred during an Aggregate operation), giving you a high-level degree of detail of what's going on within your Domain. Domain Events are one of the key tactical patterns because of their significance within the Domain, as they describe past occurrences.

 

Note

Be careful with recording too many events An ever-growing number of events is a smell. It might reveal an addiction to event recording at the Domain, most likely incentivized by the business. As a rule of thumb, remember to keep it simple.

By using CQRS, we've been able to record all the relevant events that occurred in the Domain Layer. The state of the Domain Model can be represented by reproducing the Domain Events we previously recorded. We just need a tool for storing all those events in a consistent way. We need an event store.

Note

The fundamental idea behind Event Sourcing is to...