Patterns, Principles, and Practices of Domain-Driven Design

Methods for managing complex software construction following the practices, principles and patterns of Domain-Driven Design with code examples in C#

This book presents the philosophy of Domain-Driven Design (DDD) in a down-to-earth and practical manner for experienced developers building applications for complex domains. A focus is placed on the principles and practices of decomposing a complex problem space as well as the implementation patterns and best practices for shaping a maintainable solution space. You will learn how to build effective domain models through the use of tactical patterns and how to retain their integrity by applying the strategic patterns of DDD. Full end-to-end coding examples demonstrate techniques for integrating a decomposed and distributed solution space while coding best practices and patterns advise you on how to architect applications for maintenance and scale.

• Offers a thorough introduction to the philosophy of DDD for professional developers
• Includes masses of code and examples of concept in action that other books have only covered theoretically
• Covers the patterns of CQRS, Messaging, REST, Event Sourcing and Event-Driven Architectures
• Also ideal for Java developers who want to better understand the implementation of DDD

Auteur

Scott Millett is the Director of IT for Iglu.com, and has been working with .NET since version 1.0. He was awarded the ASP.NET MVP in 2010 and 2011, and is the author of Professional ASP.NET Design Patterns and Professional Enterprise .NET. Nick Tune is a software developer delivering solutions to complex business problems using technology, collaboration, and Domain-Driven Design. He continually seeks improvement by working on ambitious products and with enthusiastic people.

Texte du rabat

Build solutions for complex business problems more effectively with Domain-Driven Design This book distills the ideas and theories of the Domain-Driven Design (DDD) philosophy into a practical playbook that you can leverage to simplify application development for complex problem domains. A focus is placed on the principles and practices of decomposing a complex problem space as well as the implementation patterns and best practices for shaping a maintainable solution space. You will learn how to build effective domain models through the use of tactical patterns and how to retain their integrity by applying the strategic patterns of DDD. Full end-to-end coding examples demonstrate techniques for integrating a decomposed and distributed solution space while coding best practices and patterns advise you on how to architect applications for maintenance and scale.

• Offers a thorough introduction to the philosophy of DDD for professional developers
• Simplifies the theories of Domain-Driven Design into practical principles and practices
• Includes masses of code and examples of concepts in action that other books have only covered theoretically
• Covers the patterns of CQRS, Messaging, REST, Event Sourcing and Event-Driven Architectures
• Ideal for developers using Java, Ruby, and other languages who want to learn common DDD implementation patterns
• Code examples presented in C# demonstrating concepts that can be applied in any language Wrox Professional guides are planned and written by working programmers to meet the real-world needs of programmers, developers, and IT professionals.Focused and relevant, they address the issues technology professionals face every day. They provide examples, practical solutions, and expert education in new technologies, all designed to help programmers do a better job.

Contenu

INTRODUCTION xxxv

PART I: THE PRINCIPLES AND PRACTICES OF DOMAIN DRIVEN DESIGN

CHAPTER 1: WHAT IS DOMAIN DRIVEN DESIGN? 3

The Challenges of Creating Software for Complex Problem Domains 4

Code Created Without a Common Language 4

A Lack of Organization 5

The Ball of Mud Pattern Stifles Development 5

A Lack of Focus on the Problem Domain 6

How the Patterns of Domain Driven Design Manage Complexity 6

The Strategic Patterns of DDD 6

Distilling the Problem Domain to Reveal What Is Important 7

Creating a Model to Solve Domain Problems 7

Using a Shared Language to Enable Modeling Collaboration 7

Isolate Models from Ambiguity and Corruption 8

Understanding the Relationships between Contexts 9

The Tactical Patterns of DDD 9

The Problem Space and the Solution Space 9

The Practices and Principles of Domain Driven Design 11

Focusing on the Core Domain 11

Learning through Collaboration 11

Creating Models through Exploration and Experimentation 11

Communication 11

Understanding the Applicability of a Model 12

Constantly Evolving the Model 12

Popular Misconceptions of Domain Driven Design 12

Tactical Patterns Are Key to DDD 12

DDD Is a Framework 13

DDD Is a Silver Bullet 13

The Salient Points 13

CHAPTER 2: DISTILLING THE PROBLEM DOMAIN 15

Knowledge Crunching and Collaboration 15

Reaching a Shared Understanding through a Shared Language 16

The Importance of Domain Knowledge 17

The Role of Business Analysts 17

An Ongoing Process 17

Gaining Domain Insight with Domain Experts 18

Domain Experts vs Stakeholders 18

Deeper Understanding for the Business 19

Engaging with Your Domain Experts 19

Patterns for Effective Knowledge Crunching 19

Focus on the Most Interesting Conversations 19

Start from the Use Cases 20

Ask Powerful Questions 20

Sketching 20

Class Responsibility Collaboration Cards 21

Defer the Naming of Concepts in Your Model 21

Behavior Driven Development 22

Rapid Prototyping 23

Look at Paper Based Systems 24

Look For Existing Models 24

Understanding Intent 24

Event Storming 25

Impact Mapping 25

Understanding the Business Model 27

Deliberate Discovery 28

Model Exploration Whirlpool 29

The Salient Points 29

CHAPTER 3: FOCUSING ON THE CORE DOMAIN 31

Why Decompose a Problem Domain? 31

How to Capture the Essence of the Problem 32

Look Beyond Requirements 32

Capture the Domain Vision for a Shared Understanding of What Is Core 32

How to Focus on the Core Problem 33

Distilling a Problem Domain 34

Core Domains 35

Treat Your Core Domain as a Product Rather than a Project 36

Generic Domains 37

Supporting Domains 37

How Subdomains Shape a Solution 37

Not All Parts of a System will be Well Designed 37

Focus on Clean Boundaries over Perfect Models 38

The Core Domain Doesn't Always Have to Be Perfect the First Time 39

Build Subdomains for Replacement Rather than Reuse 39

What if You Have no Core Domain? 39

The Salient Points 40

CHAPTER 4: MODEL DRIVEN DESIGN 41

What Is a Domain Model? 42

The Domain versus the Domain Model 42

The Analysis Model 43

The Code Model 43

The Code Model Is the Primary Expression of the Domain Model 44

Model Driven Design 44

The Challenges with Upfront Design 44

Team Modeling 45

Using a Ubiquitous Language to Bind the Analysis to the Code Model 47

A Language Will Outlive Your Software 47

The Language of the Business 48

Translation between the Developers and the Business 48

Collaborating on a Ubiquitous Language 48

Carving Out a Language by Working with Concrete Examples 49

Teach Your Domain Experts to Focus on the Problem and Not Jump to a Solution 50

Best Practices for Shaping the Language 51

How to Create Effective Domain Models 52

Don't Let the Truth Get in the Way of a Good Model 52

Model Only What Is Relevant 54

Domain Models Are Temporarily Useful 54

Be Explicit with Terminology 54

Limit Your Abstractions 54

Focus Your Code at the Right Level of Abstraction 55

Abstract Behavior Not Implementations 55

Implement the Model in Code Early and Often 56

Don't Stop at t…