WHAT'S IN THIS CHAPTER?
Understanding how WCF supports long-running business processes
Creating a declarative workflow in Visual Studio
Implementing service contracts in XAML and calling external services during the workflow
Setting up the SQLWorkflowInstanceStore
Working with Send and Receive activities and correlating outgoing and incoming messages
This chapter is an interactive walkthrough on how to create a business process in Visual Studio 2010 using WCF and workflow services. It starts with defining requirements for a case and shows how to develop the solution step by step. At the end of this chapter, you will have developed the business process, a host for the process, the clients, and other services that interact with this process. This is a complete example so you can test the process and see it in action.
Let's take a simple process (see Figure 13-1). This should be a kind of proof-of-concept to learn how to develop workflow processes. It's a classic example of a business process that deals with holiday requests.
Figure 13.1. The holiday request process
A company wants to expose a workflow as a service that receives a holiday request from its employees, waits for approval from a manager, and sends the request to the HR service.
This workflow is started by the request from the employee and the requester receives a reference ...