Professional SharePoint® 2007 Development

15.1. Workflow Foundation Basics

The Windows Workflow Foundation (WF) is a process automation platform that is integrated into SharePoint as well as many other Microsoft initiatives, including future versions of BizTalk Server and the Microsoft Dynamics product line. WF is the way to build workflow enabled solutions on the Windows platform. It provides a generalized architecture for delivering feature-rich business automation solutions while at the same time preserving the ability to integrate its various components into existing solutions. This includes applications on the server and on the client. It is this flexibility that adds to both its complexity and its power. You can embed custom workflow components into any .NET application, such as a WinForms application, and you can expose the same workflow components as a web service and access them over the Internet. The following sections explore the architectural features that enable this flexibility and highlight those most relevant to SharePoint solution development.

Workflow consists of a runtime engine and a programming model with tools for workflow developers. Windows Workflow Foundation is part of the .NET Framework 3.0 (formally known as WinFX) that includes the Windows Communication Foundation (WCF, formally known as Indigo) and the Windows Presentation Foundation (WPF, formally known as Avalon). WF provides a common infrastructure that Microsoft as well as third-party vendors will implement.

There are several key concepts ...