One of the most appreciated features of .NET Framework 4/Windows Workflow Foundation namespaces is the ability to (re)host the Workflow Designer within a line-of-business design ‘surface’ (application) with relative ease. This is especially important for ISVs that prefer to provide a domain specific Workflow authoring application instead of the Visual Studio environment - the default platform for the Workflow Designer. Of course nothing wrong with using Visual Studio if you are a developer; however imagine a supply chain engineer or a auto parts purchase manager designing or monitoring a Workflow via Visual Studio, a total non-starter. While you could ‘technically’ host the .NET3.n Workflow Designer; it was not vigorously pursued due to the complexity involved and limited feature set exposed by the Designer when hosted outside of Visual Studio.
This feature alone has excited the .NET Workflow user community and has received rave reviews and actually endeared the Workflow technology to the ISV community especially those with tight budgets and daunting project deadlines. A couple of interesting quotes are posted below.
WF 4.0 Designer Rehosting: we’ve see the light!! If you’ve done projects with WF 3.5 and you’ve tryed to make in production the Designer Rehosting feature, you can understand what I mean: in WF 3.5 hosting the Workflow Designer inside an application (a WPF application for example) is too hard, not so flexible and not so intuitive for the end user. WF team has made it much easier to rehost the designer. Using XAML for WF 4.0 has made it possible to rehost the designer on a WPF form using about three lines of code. This makes is possible to construct your custom designer in Expression; which looks pretty snazzy compared to the rehosted designers of 3.x. Read more here.
Rehosting the Workflow Designer in WF4 With Windows Workflow Foundation 4 live has become much better on the rehosting front In fact it is possible to create the fully functional and useful workflow editor below in about 200 lines of code. Now that is more like it! Read more here.
Our team is in working on a series of blog posts relating to hosting the Workflow Designer, especially focused around the specific needs of the ISV community. We expect to publish these over the next few weeks. Meanwhile do learn and acquaint yourself about hosting Workflows. Additional literature on Workflow hosting is listed below.
MSDN guidance on Rehosting .NET4 Workflow Designer: http://msdn.microsoft.com/en-us/library/dd489451(VS.100).aspx
MWinkle’s blogs on Rehosting Workflow Designer: Part 1: introductions and concepts http://blogs.msdn.com/mwinkle/archive/2009/06/17/introduction-to-wf-designer-rehosting-part-1.aspx and Part 2: implementation http://blogs.msdn.com/mwinkle/archive/2009/06/17/introduction-to-wf-designer-rehosting-part-2.aspx