Professional SharePoint® 2007 Web Content Management Development: Building Publishing Sites with Office SharePoint Server 2007

12.1. Understanding Windows Workflow Foundation

Before diving into how to leverage existing workflows or developing custom workflows, it is important for developers to have a solid grasp of WF and the motivation behind it. As with any software company, product teams develop new capabilities as they are needed within each product. At times this can result in two or more groups developing a similar component for use in different applications. The concept of workflow falls squarely in this camp. Applications such as WSS 2.0 and Content Management Server (MCMS) 2002 both had a need for workflow. At the time, the best option for adding extensible workflow to these products was to purchase a third-party solution that integrated into each of them. This was a costly proposition, both in terms of configuration and implementation, as workflow engines are typically quite sophisticated applications.

Microsoft recognized this problem of applications either developing their own workflow engine or having to rely on third parties. The logical solution was to create a core workflow engine that all applications could leverage and extend for their own specific uses and implementations. This was the motivation behind WF: to create a robust and extensible workflow engine that could be utilized not only by Microsoft's products but also by other independent software vendors (ISVs) and developers. The first release of WF was included in the .NET Framework 3.0 and is the primary reason why one of the ...