Applying Domain-Driven Design And Patterns: With Examples in C# and .net

Excerpt. © Reprinted by permission. All rights reserved.Preface: Bridging GapsPreface: Bridging GapsOn the cover of this book is a picture of the Øresund Bridge that connects Sweden and Denmark. It seems that all software architecture books must have a bridge on the cover, but there are some additional reasons the bridge is appropriate for this book.This bridge replaced a ferry that I took many times as a child. I enjoy very much driving over it even after dozens of times.On a personal note, my father was on the team that built the highest parts of the bridge.But beyond these, the main reason is that this book is very much about bridging gaps; bridging gaps between users and developers; bridging gaps between business and software; bridging gaps between logic and storage. Bridging gaps between "DB-guys" and "OO-guys"...I will refrain from making a joke about the Bridge pattern GoF Design -Patterns. Hey, how geeky can a preface be Focus of This BookThe main focus of the book is how a Domain Model could be constructed to be clean, yet still be persistence-friendly. It shows what the persistence solution could look like for such a Domain Model and especially how to bridge that gap between the Domain Model and the database.Put another way, my vision has been to provide a book that will put Eric Evans' Domain-Driven Design Evans DDD and Martin Fowler's Patterns of Enterprise Application Architecture Fowler PoEAA in context.DDD might be perceived as a bit abstract. Therefore, more concrete examples are helpful regarding persistence, for example. Mine may be fairly basic, but it is a platform to start from. This book not only explains how to use the patterns, but also how the patterns are used in O/R Mappers, for example.It has become very clear to me that "one size does not fit all" when it comes to architecture. Having said that, patterns have proven to be general enough to use and reuse in context after context.The focus isn't on the patterns themselves, but this book uses patterns in every chapter as a tool and language for discussing different design aspects. A nice side effect is that patterns-ignorant readers will also gain some insight and interest into patterns along the way.That also goes for TDD. Not all developers have become interested in this yet. I think it's especially common in the .NET community that TDD (just as patterns) is considered a niche technique at best, or it might even be totally unknown. Readers will learn how to apply TDD.Why This Book Writing my first book Nilsson NED was a really tough project on top of all my other ordinary projects and obligations. I was pretty sure I wouldn't write another, but the time came when I thought I had something to say that I couldn't leave unsaid.My change of heart started when I read two recent books that inspired me and changed my thinking. First, there was Martin Fowler's Patterns of Enterprise Application Architecture Fowler PoEAA. This book inspired me to give the Domain Model pattern another try after having failed with several earlier attempts.Then I read Eric Evans' book Domain-Driven Design Evans DDD. This book provided me with insights about how to think and act regarding development with a strong domain focus and with a certain style of how to apply the Domain Model pattern.Another important influence was all that I learned from teaching my patterns course over a couple of years. As I interacted with students and the material evolved, I had insights myself.My views of DDD transformed as I worked on an ambitious (though unfortunately unfinished) open source project called Valhalla, which I developed in collaboration with Christoffer Skjoldborg. (Christoffer did by far the most work.)To summarize all this, I felt that a book that dealt more with application than theory was needed, but one that was based on solid ground, such as the DDD and PoEAA books. "Applying" feels close to my heart because I consider myself a developer above anyth
Author: Nilsson, Jimmy

Publisher: Addison-Wesley Professional

Binding: Hardcover

Language: English

ISBN-10: 0321268202

ISBN-13: 9780321268204