AZURE .NET SERVICES WORKFLOWS in Visual C#

Creator Data Matrix ECC200 in Visual C# AZURE .NET SERVICES WORKFLOWS

Go back to the State Machine Workflow design surface and drag and drop four state artifacts onto the design surface and name them WaitingForShoppingCartItem, ShoppingCartItemPlaced, ItemCheckOut, and CartClosed, as shown in Figure 7-8. The process to work out the logic of state transaction is the same as the process to work on the standard WF state machine. Please see http://msdn.microsoft.com/ en-us/netframework/aa663328.aspx to understand Microsoft Windows Workflow Foundation and how to work on the WF state machine design in Visual Studio.

Figure 7-8. States defined in ShoppingCartWorkflow state machine 5. Now let's build up the state machine used to handle a shopping cart service. Implement a code-behind for the ShoppingCartItemWorkflow state machine as shown in Listing 7-8. The event handler functions in the code-behind will be bound to events in the state machine during the next state machine design. This shopping cart example has four state transaction handlers from the code-behind. These handlers are generated from the WF design surface; insert the code from the listing into the handlers bodies. (Right-click the design surface and select View Code, or press F7, to get into the state transaction handler body.) There is an array called NextItem defined in each handler, which is the data contract of the WCF services in this example. The member items in the array also have the type of NextItem that is used to simulate the business activities, such as shopping cart data insert, update, or delete. The state will be transacted depending on the activities in the handler.

Listing 7-8. Code-behind for ShoppingCartWorkflow using using using using using using using using using using using using using using using using System; System.ComponentModel; System.ComponentModel.Design; System.Collections; System.Drawing; System.Linq; System.Workflow.ComponentModel.Compiler; System.Workflow.ComponentModel.Serialization; System.Workflow.ComponentModel; System.Workflow.ComponentModel.Design; System.Workflow.Runtime; System.Workflow.Activities; System.Workflow.Activities.Rules; System.ServiceModel.Web; ShoppingCartServiceLibrary; System.ServiceModel;

namespace ShoppingCartWorkflows { using ShoppingCartServiceLibrary; public sealed partial class ShoppingCartItemWorkflow : StateMachineWorkflowActivity { public ShoppingCartItem receivedShoppingCartItem; public string receivedId; public ShoppingCartItem currentShoppingCartItem; public CreditCardPayment ShoppingCartItemCreditCardPayment; public ShoppingCartItemWorkflow() { InitializeComponent(); } private void OnShoppingCartItemPlacedCode_ExecuteCode(object sender, EventArgs { var id = WorkflowEnvironment.WorkflowInstanceId.ToString(); currentShoppingCartItem = new ShoppingCartItem(); currentShoppingCartItem.ShoppingCartItemId = id; currentShoppingCartItem.Price = receivedShoppingCartItem.Price; currentShoppingCartItem.ItemName = receivedShoppingCartItem.ItemName; currentShoppingCartItem.NextItem = new NextItem[] { new NextItem { Relative = ShoppingCartItem.ENDPOINT_CREDITCARD_PAYMENT, Uri = string.Format("{0}{1}", ShoppingCartItem.CREDIT_CARD_PAYMENT_URI, WorkflowEnvironment.WorkflowInstanceId.ToString()), e)

}, new NextItem { Relative = ShoppingCartItem.ENDPOINT_ITEM_UPDATE, Uri = string.Format("{0}{1}", WorkflowEnvironment.WorkflowInstanceId.ToString()) }, new NextItem { ShoppingCartItem.SHOPPING_CART_URI, Relative = ShoppingCartItem.ENDPOINT_ITEM_DELETE, Uri = string.Format("{0}{1}", ShoppingCartItem.SHOPPING_CART_URI, WorkflowEnvironment.WorkflowInstanceId.ToString()) } }; WebOperationContext.Current.OutgoingResponse.StatusCode = System.Net.HttpStatusCode.Created; } private void codeUpdateShoppingCartItem_ExecuteCode(object sender, EventArgs e) { var id = WorkflowEnvironment.WorkflowInstanceId.ToString(); currentShoppingCartItem.ShoppingCartItemId = receivedId; currentShoppingCartItem.ItemName = receivedShoppingCartItem.ItemName; currentShoppingCartItem.Price = receivedShoppingCartItem.Price; currentShoppingCartItem.NextItem = new NextItem[] { new NextItem { Relative = ShoppingCartItem.ENDPOINT_CREDITCARD_PAYMENT, Uri = string.Format("{0}{1}", ShoppingCartItem.CREDIT_CARD_PAYMENT_URI, id.ToString()), }, new NextItem { Relative = ShoppingCartItem.ENDPOINT_ITEM_UPDATE, Uri = string.Format("{0}{1}", ShoppingCartItem.SHOPPING_CART_URI, id.ToString()), }, new NextItem { Relative = ShoppingCartItem.ENDPOINT_ITEM_DELETE, Uri = string.Format("{0}{1}", ShoppingCartItem.SHOPPING_CART_URI, id.ToString()), } };

WebOperationContext.Current.OutgoingResponse.StatusCode = System.Net.HttpStatusCode.OK; } private void codePayShoppingCartItem_ExecuteCode(object sender, EventArgs e) { var id = WorkflowEnvironment.WorkflowInstanceId.ToString(); currentShoppingCartItem.ShoppingCartItemId = receivedId; currentShoppingCartItem.ItemName = receivedShoppingCartItem.ItemName; currentShoppingCartItem.Price = receivedShoppingCartItem.Price; currentShoppingCartItem.NextItem = new NextItem[] { new NextItem { Relative = ShoppingCartItem.ENDPOINT_CREDITCARD_PAYMENT, Uri = string.Format("{0}{1}", ShoppingCartItem.CREDIT_CARD_PAYMENT_URI, id.ToString()), }, new NextItem { Relative = ShoppingCartItem.ENDPOINT_ITEM_UPDATE, Uri = string.Format("{0}{1}", ShoppingCartItem.SHOPPING_CART_URI, id.ToString()), }, new NextItem { Relative = ShoppingCartItem.ENDPOINT_ITEM_DELETE, Uri = string.Format("{0}{1}", ShoppingCartItem.SHOPPING_CART_URI, id.ToString()), } }; WebOperationContext.Current.OutgoingResponse.StatusCode = System.Net.HttpStatusCode.Created; } private void codeCheckOutShoppingCartItem_ExecuteCode(object sender, EventArgs e) { WebOperationContext.Current.OutgoingResponse.StatusCode = System.Net.HttpStatusCode.Created; } } }

Now we need to bind the state machine workflow item properties to the corresponding handler. Figure 7-9 shows the bindings for WaitingForShoppingCartItem:eventItemAdded.

The bindings for ShoppingCartItemPlaced:eventItemUpdated are shown in Figure 7-10.

Bindings for ShoppingCartItemWorkflow:ShoppingCartItemPlaced are shown in Figure 7-11.

Bindings for ShoppingCartItemWorkflow:StateCheckout are shown in Figure 7-12.

10. Bindings for ShoppingCartItemWorkFlow:Timeout are shown in Figure 7-13.

Figure 7-13. Bindings for ShoppingCartItemWorkFlow:Timeout 11. Create a host project, ShoppingCartWorkflowServiceHost, as Listing 7-9 shows. There are three callback delegates created in the Main() method. The first two are used to output trace information regarding the state transaction, and the third one is used to bind the persistence service for the workflow, so we can persist the workflow state. Listing 7-9. Create a Host Project ShoppingCartWorkflowServiceHost to Run the Workflow as a Service using using using using using using using using using System; System.Collections.Generic; System.Linq; System.Text; System.Threading; System.Workflow.Runtime; System.Workflow.Runtime.Hosting; System.ServiceModel; System.ServiceModel.Description;