Book Image

MVVM Survival Guide for Enterprise Architectures in Silverlight and WPF

Book Image

MVVM Survival Guide for Enterprise Architectures in Silverlight and WPF

Overview of this book

MVVM (Model View View Model) is a Microsoft best practices pattern for working in WPF and Silverlight that is highly recommended by both Microsoft and industry experts alike. This book will look at the reasons for the pattern still being slow to become an industry standard, addressing the pain points of MVVM. It will help Silverlight and WPF programmers get up and running quickly with this useful pattern.MVVM Survival Guide for Enterprise Architectures in Silverlight and WPF will help you to choose the best MVVM approach for your project while giving you the tools, techniques, and confidence that you will need to succeed. Implementing MVVM can be a challenge, and this book will walk you through the main issues you will come across when using the pattern in real world enterprise applications.This book will help you to improve your WPF and Silverlight application design, allowing you to tackle the many challenges in creating presentation architectures for enterprise applications. You will be given examples that show the strengths and weaknesses of each of the major patterns. The book then dives into a full 3 tier enterprise implementation of MVVM and takes you through the various options available and trade-offs for each approach. During your journey you will see how to satisfy all the demands of modern WPF and Silverlight enterprise applications including scalability, testability, extensibility, and blendability.Complete your transition from ASP.NET and WinForms to Silverlight and WPF by embracing the new tools of these platforms, and the new design style that they allow for. MVVM Survival Guide for Enterprise Architectures in Silverlight and WPF will get you up to speed and ready to take advantage of this powerful new presentation platform.
Table of Contents (21 chapters)
MVVM Survival Guide for Enterprise Architectures in Silverlight and WPF
Credits
Foreword
About the Authors
About the Reviewer
www.PacktPub.com
Preface
MVVM Frameworks
Index

Chapter 1. Presentation Patterns

By Ryan Vice

Separation of Concerns or SoC is a core principle of enterprise software development which provides many benefits and has been a key driving force behind many presentation (or UI) design patterns that have emerged over the last 30 years. In the arena of Silverlight and WPF development, Model View View Model or MVVM has quickly become the de-facto pattern for achieving SoC in UIs. However, this pattern often leaves developers and architects frustrated and at the time of this writing, can be difficult to implement in an effective way that provides more benefits than some of the older, more familiar presentation patterns (MVC, MVP, and so on).

In this chapter we will cover the evolution of presentational patterns along with the problems that are solved by each pattern along the evolutionary path. We will also dive into the shortcomings of each pattern which led to the next pattern in the evolution and will finish this chapter ready to look at MVVM.

We will begin this chapter by reviewing the functionality of the Project Billing sample application that we will use throughout this book. We will follow this by briefly talking about the various types of state that must be managed in UI applications. Then we dive into the history of presentational patterns and as we go through the history we will implement Project Billing using each pattern to show you explicitly the benefits and the shortcomings of each pattern that lead to the next pattern in the evolution. This will help you understand why you'd want to use MVVM through examples and make the benefits of MVVM easier to appreciate when we dive into that topic in the next chapter. This would also help you evangelize the pattern on your projects if needed and be able to explain what benefits MVVM would offer over other presentation patterns.

If you are already familiar with (or not interested in) the history of presentation patterns, you should still at a minimum review the following sections:

  • The Project Billing sample application: This section will review the functionality of the sample application that will be used in the first two chapters

  • Types of state: This section defines and discusses the various types of state that need to be managed in a UI application

  • Monolithic design: The introduction of this section discusses the coupling that results from not using some kind of presentational design pattern

    • The problems with Monolithic design: This section discusses the many problems that result from not using presentational design patterns

  • Data service stub: This section covers creating the data service stub that will be used by the Project Billing application throughout this book

  • Memory leaks: This section covers how .NET events can cause memory leaks

However, I'd recommend that unless you are intimately familiar with patterns such as Model 2 and Passive View that you take the time to go through this chapter as this knowledge will be very useful in driving home some of the fundamentals of presentation patterns which will help you adapt these notoriously flexible patterns to your needs