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

Doctrine Events


Domain Events are not just for doing batch jobs such as sending emails or communicating to other Bounded Contexts; they're also interesting for performance and scalability improvements. Let's see an example.

Consider the following scenario. You have an e-commerce application. Your main persistence mechanism is MySQL, but for browsing and filtering your catalog, you're using a better approach, such as Elasticsearch or Solr. On Elasticsearch, you'll end up with a subset of the information stored in your full database. How do you keep the data in sync? What happens when the Content Team updates the catalog from the back office tool?

There have been people re-indexing the entire catalog from time to time. This is very expensive and slow. A smarter approach may be updating one or some of the documents related to the Product that has been updated. How can we do that? Using Domain Events.

However, if you've been working with Doctrine, this is likely not something that's new to you...