Book Image

Programming Windows Workflow Foundation: Practical WF Techniques and Examples using XAML and C#

By : Kenneth Scott Allen
Book Image

Programming Windows Workflow Foundation: Practical WF Techniques and Examples using XAML and C#

By: Kenneth Scott Allen

Overview of this book

Windows Workflow Foundation (WF) is a technology for defining, executing, and managing workflows. It is part of the .NET Framework 3.0 and will be available natively in the Windows Vista operating system. Windows Workflow Foundation might be the most significant piece of middleware to arrive on the Windows platform since COM+ and the Distributed Transaction Coordinator. The difference is, not every application needs a distributed transaction, but nearly every application does have a workflow encoded inside it. In this book, K Scott Allen, author of renowned .NET articles at www.odetocode.com, provides you with all the information needed to develop successful products with Windows Workflow. From the basics of how Windows Workflow can solve the difficult problems inherent in workflow solutions, through authoring workflows in code, learning about the base activity library in Windows Workflow and the different types of workflow provided, and on to building event-driven workflows using state machines, workflow communications, and finally rules and conditions in Windows Workflow, this book will give you the in-depth information you need. Throughout the book, an example "bug reporting" workflow system is developed, showcasing the technology and techniques used.
Table of Contents (14 chapters)
Programming Windows Workflow Foundation: Practical WF Techniques and Examples using XAML and C#
Credits
About the Author
About the Reviewer
Preface

Our First State Machine


As detailed in Chapter 2, we can author workflows using code only, XAML only, or a combination of code and XAML (code-separation). State machine workflows are no different in this respect. We will build the workflows in this chapter using the code-separation approach, although any of the authoring modes would work.

Our workflow will support a bug-tracking application. Specifically, we will be tracking the life cycle of a software bug as the bug moves from an Open state to a Closed state. During its lifetime, a bug might also be in the Assigned, Resolved, and Deferred states.

Why use a state machine to model the workflow of bug fixes? Because is it impossible to model the choices a bug will need to reach a completed state. Think about the decision-making required at each step in a bug's life. A newly opened bug requires some evaluation. Is the bug a duplicate? Is the bug really a bug? Even if the bug really is a defect, not all defects move directly to someone's work...