Domain-Driven Design in PHP
Domain-Driven Design in PHP
Discover DDD, Architectural Styles, Tactical Design Implementations, and Bounded Context Integration with PHP 7.4 examples
About the Book
In 2014, after two years of reading about and working with Domain-Driven Design, Carlos and Christian, friends and workmates, traveled to Berlin to participate in Vaughn Vernon's Implementing Domain-Driven Design Workshop. The training was fantastic, and all the concepts that were swirling around in their minds prior to the trip suddenly became very real. However, they were almost no PHP developers in a room full of Java and .NET developers.
Around the same time, Keyvan co-founded Funddy, a crowdfunding platform for the masses built on top of the concepts and building blocks of Domain-Driven Design. Domain-Driven Design proved itself effective in the exploratory process and modeling of building an early-stage startup like Funddy. It also helped handle the complexity of the company, with its constantly changing environment and requirements. And after connecting with Carlos and Christian and discussing the book, Keyvan proudly signed on as the third writer.
Domain-Driven Design has arrived to the PHP community with lots of talk but no real code detailing how to implement Tactical DDD patterns or how to integrate Bounded Contexts with REST and/or messaging strategies. Without being in a Training session and no PHP real examples, learning DDD can be challenging.
Together, we've written the book we wanted to have when we started with Domain-Driven Design. It's full of examples, production-ready code, shortcuts, and our recommendations based on our experiences of what worked and what didn't for our respective teams. We arrived at Domain-Driven Design via its building blocks — Tactical Patterns — which is why this book is mainly about them. Reading it will help you learn them, write them, and implement them. You'll also discover how to integrate Bounded Contexts using synchronous and asynchronous approaches, which will open your world to strategic design — though the latter is a road you'll have to discover on your own.
About the Contributors

Addicted to software development, who loves to share the knowledge he learns with others. Enjoys exploring many areas of the field, ranging from algorithms to software architectural design. Co-hosts a weekly development podcast found at ThreeDevsandAMaybe.com. Has worked in an agency setting, freelance and now at MyBuilder.
Reader Testimonials

Raúl Araya (@nubeiro)
Lead Developer at NordPay Financial
Last part of the book should be called “developer p0rn”. I really enjoyed the contents. Looking forward to see it actually finished.

Axxon (@PhronimaAxxon)
Coder and Musician
Thanks for that practical guide about EventStore in PHP. Just need to play with it now!

Paulo Victor (@Pv_Fusion)
Open Source Developer
Currency and Money its great practical example on @dddbook #DDDinPHP

Ignacio Sánchez (@isholgueras)
Front-end and Drupal Developer
I bought it yesterday, awesome book. Highly recommended! Thanks guys!

Tim Glabisch (@timglabisch)
Developer at SensioLabs Deutschland
I bought it yesterday and read all the night. Awesome #book, every #php dev should read!

Fernando Arconada (@farconadaT3)
Author of “Testing for Symfony 2 Applications”
It's an awesome book
Table of Contents
- Foreword by Matthias Noback
-
Preface
- Who Should Read This Book
- DDD and PHP Community
- Summary of Chapters
- Code and Examples
- Acknowledgements
-
About the Authors
- Carlos Buenosvinos
- Christian Soronellas
- Keyvan Akbary
-
Getting Started with Domain-Driven Design
- Why Domain-Driven Design Matters
- The Three Pillars of Domain-Driven Design
- Considering Domain-Driven Design
- The Tricky Parts
- Strategical Overview
- Related Movements: Microservices and Self-Contained Systems
- Wrap-Up
-
Architectural Styles
- Spaghetti Architecture
- Layered Architecture
- Hexagonal Architecture: Inverting Dependencies
- Command Query Responsibility Segregation (CQRS)
- Event Sourcing
- Wrap-Up
-
Value Objects
- Definition
- Value Object vs. Entity
- Currency and Money Example
- Characteristics
- Basic Types
- Testing Value Objects
- Persisting Value Objects
- Security
- Wrap-Up
-
Entities
- Introduction
- Objects vs. Primitive Types
- Identity Operation
- Persisting Entities
- Testing Entities
- Validation
- Entities and Domain Events
- Wrap-Up
-
Services
- Application Services
- Domain Services
- Domain Services and Infrastructure Services
- Testing Domain Services
- Anemic Domain Models vs. Rich Domain Models
- Wrap-Up
-
Domain Events
- Introduction
- Definition
- Characteristics
- Modeling Events
- Doctrine Events
- Persisting Domain Events
- Publishing Events from the Domain Model
- Spreading the News to Remote Bounded Contexts
- Wrap-Up
-
Modules
- General Overview
- Leverage Modules in PHP
- Bounded Contexts and Applications
- Structuring Code in Modules
- Wrap-Up
-
Aggregates
- Introduction
- Key Concepts
- What Is an Aggregate?
- Why Aggregates?
- A Bit of History
- Anatomy of an Aggregate
- Aggregate Design Rules
- Sample Application Service: User and Wishes
- Transactions
- Wrap Up
-
Factories
- Factory Method on Aggregate Root
- Factory on Service
- Testing Factories
- Wrap-Up
-
Repositories
- Definition
- Repositories Are Not DAOs
- Collection-Oriented Repositories
- Persistence-Oriented Repository
- Extra Behavior
- Querying Repositories
- Managing Transactions
- Testing Repositories
- Testing Your Services with In-Memory Implementations
- Wrap-Up
-
Application
- Requests
- Anatomy of an Application Service
- Testing Application Services
- Transactions
- Security
- Domain Events
- Command Handlers
- Wrap-Up
-
Integrating Bounded Contexts
- Integration Through the Data Store
- Integration Relationships
- Implementing Bounded Context Integrations
- Wrap-Up
-
Appendix: Hexagonal Architecture with PHP
- Introduction
- First Approach
- Repositories and the Persistence Edge
- Decoupling Business and Persistence
- Migrating our Persistence to Redis
- Decouple Business and Web Framework
- Rating an idea using the API
- Console app rating
- Testing Rating an Idea UseCase
- Testing Infrastructure
- Arggg, So Many Dependencies!
- Domain Services and Notification Hexagon Edge
- Let’s Recap
- Hexagonal Architecture
- Key Points
- What’s Next?
- The End
- Bibliography
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