DinnerNow中的Work Flow应用(上) --- 订单流程
作为微软最新技术应用的DEMO。dinnernow使用了: IIS7, ASP.NET Ajax Extensions, LINQ, WCF, WF,WPF,Windows PowerShell, Card Space以及 .NET Compact Framework. 本文将会继续订餐流程，来讨论关于WF(Windows Work Flow Foundation), 在"订单"这一应用场景中的设计思路:)
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首先请你们看一下这张图，它标明了在定单这一业务流程中WF在DinnerNow架构中所实际执行的方法顺序及所处位置．
继续上一篇中的选餐页面，当咱们选择了可口的饭菜以后，就要去进入定单及付费流程了．请单击选餐页面中的checkout按钮，这时页面会跳转了checkout.aspx页。当咱们输入了Delivery Address的相关信息并提交信息后，页面会继续停留在当前页上并要求咱们继续输入Payment Option，直到再次提交后，就会看到下面的页面了：
当咱们确认输入的相关信息后，点击bringmymeal按钮后，就开始建立相应的订单信息了．下面咱们就开始今天的内容:)web
首先请用VS2008打开下面两个解决方案:
安装目录下\solution\DinnerNow - Web\DinnerNow - Web.sln
\solution\DinnerNow - ServicePortfolio2\DinnerNow - ServicePortfolio2.sln数据库
先切换到DinnerNow - Web.sln下的DinnerNow.WebUX项目中的check.aspx文件，找到SubmitOrder()方法： 编程
{
DinnerNow.ShoppingCartService.SubmitOrder(
submitorder_onSuccess,service_onError, null );
}
由于上面的代码最终会去调用ShoppingCartService.cs（位于当前项目的Code文件夹下）中的同名方法: 架构
public void SubmitOrder()
{
ShoppingCartDataSource datasource = (ShoppingCartDataSource)HttpContext.Current.Session[StateKeys.ShoppingCart];
Order order = (Order)HttpContext.Current.Session[StateKeys.Order]; // 获取刚才输入的订单信息
order.SubmittedDate = DateTime.Now;
order.OrderItems = (from oi in shoppingCart.Items
select new OrderItem()
{
Eta = DateTime.Now.AddMinutes(oi.DeliveryTime),
MenuItemId = new Guid(oi.MenuItemIdentifier),
MenuItemName = oi.MenuItemName,
Quantity = oi.Quantity,
RestaurantId = new Guid(oi.RestaurantIdentifier),
RestaurantName = oi.RestaurantName,
Status = " Ordered " ,
StatusUpdatedTime = DateTime.Now,
UnitCost = oi.Price
}).ToArray < DinnerNow.WebUX.OrderProcessingService.OrderItem > ();
order.Total = (from oi in shoppingCart.Items
select new { orderAmount = oi.Price * oi.Quantity }).Sum(o => o.orderAmount);
datasource.SubmitOrder(order);
HttpContext.Current.Session[StateKeys.ShoppingCart] = null ;
}
上面代码中的HttpContext.Current.Session[StateKeys.Order]里面存储的就是刚才咱们输入的相关订单信息（我我的认为这里使用Session有些不妥）．ide
另外上面的OrderItems的类型声明以下(来自DinnerNow - ServicePortfolio2.sln下的DinnerNow.Business
项目中的Data\Order.cs文件): 网站
[Serializable]
public class OrderItem
{
[DataMember]
public string RestaurantName { get ; set ; }
[DataMember]
public Guid RestaurantId { get ; set ; }
[DataMember]
public Guid MenuItemId { get ; set ; }
[DataMember]
public string MenuItemName { get ; set ; }
[DataMember]
public string MenuItemImageLocation { get ; set ; }
[DataMember]
public int Quantity { get ; set ; }
[DataMember]
public decimal UnitCost { get ; set ; }
[DataMember]
public string Status { get ; set ; }
[DataMember]
public DateTime StatusUpdatedTime { get ; set ; }
[DataMember]
public Guid WorkflowId { get ; set ; }
[DataMember]
public DateTime Eta { get ; set ; }
}
这个类中的字段WorkflowId保存是订单所使用的工做流id, 这个值在订单建立时不会被赋值，但当订单状态更新时会被赋值．而相应的工做流的状态会持久化到SQLSERVER数据库中（会在接下来的内容中加以说明）。ui
目前咱们仍是要再回到 SubmitOrder() 代码段中，找到datasource.SubmitOrder(order)这行代码，而这行代码要执行的是下面的方法：this
{
using (DinnerNow.WebUX.OrderProcessingService.ProcessOrderClient proxy = new ProcessOrderClient())
{
proxy.Processorder(order); // 该行代码未来执行绑定到SVC服务上的工做流
}
this .items = new List < ShoppingCartItem > ();
}
上面代码中的ProcessOrderClient类实际上添加SVC引用时系统自动生成的类．
而引用的路径即: http://localhost/dinnernow/service/OrderProcess.svc
该文件位于ServicePortfolio2.sln下的DinnerNow.ServiceHost/OrderProcess.svcspa
因此这里咱们要切换到ServicePortfolio2.sln解决方案下．并打开DinnerNow.ServiceHost项目中的
OrderProcess.svc ，这个文件中的头部是这样声明的:
Factory = " System.ServiceModel.Activation.WorkflowServiceHostFactory "
Service = " DinnerNow.OrderProcess.ProcessOrder " %>
其中的Factory="System.ServiceModel.Activation.WorkflowServiceHostFactory"会绑定到一个工
做流，且这个工做流会有持久化访问数据库的属性．固然咱们能够在web.config(位于这个项目中)找到下面的内容:
enablePerformanceCounters = " true " >
< services >
< add type = " System.Workflow.Runtime.Hosting.SharedConnectionWorkflowCommitWorkBatchService, System.Workflow.Runtime, Version=3.0.00000.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35 " />
< add type = " System.Workflow.Runtime.Hosting.SqlWorkflowPersistenceService, System.Workflow.Runtime, Version=3.0.00000.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35 " />
< add type = " System.Workflow.Runtime.Tracking.SqlTrackingService,System.Workflow.Runtime,Version=3.0.00000.0, Culture=neutral,PublicKeyToken=31bf3856ad364e35 " />
</ services >
< commonParameters >
< add name = " ConnectionString " value = " Data Source=daizhj\daizhj;User ID=sa;Password=123123;Initial Catalog=dinnernow;Pooling=true " />
</ commonParameters >
</ workflowRuntime >
而属性ConnectionString就是持久化时用到的数据库连接串.
看到这里，本文的内容将会转到WF上了，由于上面的C#代码中的proxy.Processorder(order)方法在是WF中绑定的．按照上面的SVC声明，找到ProcessOrder.xoml文件(位于当前解决方案中DinnerNow.OrderProcess项目下)．
这里咱们经过双击该文件查看其工做流的大体流程:
咱们在第一个Activity上击鼠标右键在菜单中找到"属性"，以下图：
其中的ServiceOperationInfo中的绑定属性就是该Activity所实现的操做，这里写的是:
DinnerNow.OrderProcess.IProcessOrder.Processorder,看来对于外部发来的SOAP请求要先到达这里被活动处理．
经过上图中的属性咱们能够看出这个Activity是一个ReceiveActivity, 这个组件是.net 3.5 才引入的，以下图所示：
该组件主要用于处理Web服务请求．固然有进就有出，在这个顺序工做流中还使用了另一个新引入的组件：SendActivity, 将会在后面加以说明:)
即然找到了请求的操做，下一步就要好好看一下这个工做流了，由于顺序工做流本地比较好理解，这里就直接一个一个activity加以说明了.
首先请加开Workflow\ProcessOrder.xoml.cs文件，它的前半部分代码内容以下:
{
public static DependencyProperty incomingOrderProperty = DependencyProperty.Register( " incomingOrder " , typeof (DinnerNow.Business.Data.Order), typeof (DinnerNow.OrderProcess.ProcessOrder));
public static DependencyProperty orderIDProperty = DependencyProperty.Register( " orderID " , typeof (System.Guid), typeof (DinnerNow.OrderProcess.ProcessOrder));
public RestaurantOrder[] Order { get ; set ; }
[DesignerSerializationVisibilityAttribute(DesignerSerializationVisibility.Visible)]
[BrowsableAttribute( true )]
public DinnerNow.Business.Data.Order IncomingOrder
{
get
{
return ((DinnerNow.Business.Data.Order)( base .GetValue(DinnerNow.OrderProcess.ProcessOrder.incomingOrderProperty)));
}
set
{
base .SetValue(DinnerNow.OrderProcess.ProcessOrder.incomingOrderProperty, value);
}
}
[DesignerSerializationVisibilityAttribute(DesignerSerializationVisibility.Visible)]
[BrowsableAttribute( true )]
public Guid orderID
{
get
{
return ((System.Guid)( base .GetValue(DinnerNow.OrderProcess.ProcessOrder.orderIDProperty)));
}
set
{
base .SetValue(DinnerNow.OrderProcess.ProcessOrder.orderIDProperty, value);
}
}
}
能够看到这里使用了DependencyProperty（依赖属性）, 有关这方面的内容能够参见这篇文章:
《WF编程》系列之38 - 依赖属性
这里使用它是为了活动数据绑定（在activity之间进行数据传递），由于在上面提到过，客户端网站要提到定单信息过来，而订单的数据将会绑定到这个工做流文件的IncomingOrder属性上．
如今有了数据，该执行建立定单的操做了，而这个任务交给了下一个Activity---"saveOrderActivity1", 咱们能够从该活动的类型上看出它是一个SaveOrderActivity(DinnerNow.WorkflowActivities项目下)，而这个活动类型的代码段以下:
{
public static DependencyProperty IncomingOrderProperty = DependencyProperty.Register( " IncomingOrder " , typeof (DinnerNow.Business.Data.Order), typeof (SaveOrderActivity));
public static DependencyProperty orderIDProperty = DependencyProperty.Register( " orderID " , typeof (System.Guid), typeof (SaveOrderActivity));
public SaveOrderActivity()
{
InitializeComponent();
}
[Description( " Customer Order " )]
[Browsable( true )]
[Category( " Order " )]
[DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
public DinnerNow.Business.Data.Order IncomingOrder
{
get
{
return ((DinnerNow.Business.Data.Order)( base .GetValue(SaveOrderActivity.IncomingOrderProperty)));
}
set
{
base .SetValue(SaveOrderActivity.IncomingOrderProperty, value);
}
}
[DesignerSerializationVisibilityAttribute(DesignerSerializationVisibility.Visible)]
[BrowsableAttribute( true )]
[CategoryAttribute( " Parameters " )]
public Guid orderID
{
get
{
return ((System.Guid)( base .GetValue(SaveOrderActivity.orderIDProperty)));
}
set
{
base .SetValue(SaveOrderActivity.orderIDProperty, value);
}
}
protected override ActivityExecutionStatus Execute(ActivityExecutionContext executionContext)
{
OrderService service = new OrderService();
orderID = service.CreateOrder(IncomingOrder);
return ActivityExecutionStatus.Closed;
}
}
固然这里也用了DependencyProperty来接收从上一个活动(ReceiveActivity)传递来的参数，并对其进行操做。清注意上面代码段中的Execute方法，它便是用来建立订单的代码．该方法中的语句：
service.CreateOrder(IncomingOrder)；
所执行的操做以下:
{
using (Business.OrderProcessing op = new DinnerNow.Business.OrderProcessing())
{
return op.CreateOrder(newOrder);
}
}
固然上面代码中的OrderProcessing是对订单（CRUD）服务的外部封装．我我的认为这种封装仍是很好
必要的(毫不是***子放屁，画蛇添足)，它会让业务操做和数据（库）操做相分离，由于上面代码中的：
op.CreateOrder(newOrder)
将会是LINQ方式的数据表操做，以下:
{
// Check customer exists in database
var customerId = (from c in db.Customers
where c.UserName == newOrder.CustomerUserName
select c.CustomerId).FirstOrDefault();
if (customerId == Guid.Empty)
{
// need to add a new customer OR is this a bug?
customerId = Guid.NewGuid();
db.Customers.InsertOnSubmit( new DinnerNow.Data.Customer() { CustomerId = customerId, UserName = newOrder.CustomerUserName, UserId = Guid.Empty });
}
var orderId = (newOrder.OrderId == Guid.Empty ? Guid.NewGuid() : newOrder.OrderId);
var order = new DinnerNow.Data.Order()
{
City = newOrder.City,
ContactTelephone = newOrder.ContactTelephone,
CustomerID = customerId,
OrderId = orderId,
OrderPayments = new DinnerNow.Data.OrderPayment()
{
Address = newOrder.Payment.Address,
City = newOrder.Payment.City,
Country = newOrder.Payment.Country,
CreditCardNumber = newOrder.Payment.CardNumber.Substring( 0 , 4 ),
CreditCardType = newOrder.Payment.CreditCardType,
ExpirationDate = newOrder.Payment.ExpirationDate,
PostalCode = newOrder.Payment.PostalCode,
State = newOrder.Payment.State,
NameOnCard = newOrder.Payment.NameOnCard,
OrderID = orderId,
PaymentID = Guid.NewGuid()
},
PostalCode = newOrder.PostalCode,
State = newOrder.State,
StreetAddress = newOrder.StreetAddress,
SubmittedDate = newOrder.SubmittedDate,
Total = newOrder.Total
};
order.OrderDetails.AddRange(from od in newOrder.OrderItems
select new DinnerNow.Data.OrderDetail()
{
OrderDetailId = Guid.NewGuid(),
OrderId = orderId,
MenuItemId = od.MenuItemId,
Quantity = od.Quantity,
RestaurantId = od.RestaurantId,
UnitCost = od.UnitCost,
Status = " New Order " ,
StatusUpdatedTime = DateTime.Now,
ETA = od.Eta
});
db.Orders.InsertOnSubmit(order);
db.SubmitChanges();
return order.OrderId;
}
上面代码主要是向数据库中的Order(订单表),OrderDetail（订单名称表）两个表中插入记录.同时将插入订单记录的编号返回给依赖属性Guid orderID.
而接下来的工做就是要去获取该订单与餐馆绑定关系信息了．这个任务被下一个Activity所执行，即:
CreateRestaurantOrdersCode
{
DinnerNow.Business.OrderProcessing service = new DinnerNow.Business.OrderProcessing();
Order = service.GetRestaurantOrders(orderID);
}
而上面的GetRestaurantOrders(orderID)最终会调用下面的代码(DinnerNow.Business\OrderProcessing.cs)：
{
var ordersByRestaurant = (from od in db.OrderDetails
where od.OrderId == orderID
select new DinnerNow.Business.Data.RestaurantOrder()
{
OrderId = od.OrderId,
RestaurantId = od.RestaurantId
}).Distinct();
return ordersByRestaurant.ToArray();
}
由于代码很简单，就很少说了:)
执行完上述操做后，就须要将新建立的订单转入业务流程了，这时会根据业务操做的不断推动，从而使该订单状态不断获得更新，但由于这些后续操做不是在几秒或几分钟分就要完成了，它要在餐馆与订餐人中的不断交互中推动，就像是在淘宝买东西差很少，有的交易能够要十天半个月甚至更长时间内才会完成．因此在工做流中使用的持久化，也就是前面所说的数据库存储:)
好了，完成了这个ACTIVITY以后，工做流的下一站就是replicatorActivity1，咱们能够在该活动的属性页中找到它的相关设置以下图:
能够看出它的执行方式是: parallel（并行）初始化childData: Activity=ProcessOrder, Path=Order
而它的ChildInitialize方法(构造方法)为:ChildInit，该方法的内容以下:
{
RestaurantOrderContainer container = e.Activity as RestaurantOrderContainer;
(container.Activities[ 0 ] as SendActivity).ParameterBindings[ 0 ].Value = e.InstanceData as RestaurantOrder;
(container.Activities[ 0 ] as SendActivity).ParameterBindings[ 1 ].Value = new Dictionary < string , string > ((container.Activities[ 1 ] as ReceiveActivity).Context);
}
看来它是要将要请求发送的数据（RestaurantOrderContainer提供）绑定到SendActivity上，它包括一个RestaurantOrder,和一个活动的上下文信息．好的，这里有必要介绍一下SendActivity, 它是在.net 3.5中引入的发送Soap请求的组件，有了它就能够发送服务请求到指定的svc（服务）上并可获取执行该服务的返回结果．
而这什么要使用它，这里不妨对下一篇文章中的内容作一下介绍：该SendActivity将会调用OrderUpdateService.svc服务，而这个SVC偏偏又是一个状态机工做流，它主要执行定单状态的流转更新操做．因此DinnerNow实现的是一个从顺序工做流向另外一个状态机工做流发送SOAP请求的流程．而这些内容会在下一篇文章中进行介绍．
今天的内容就先告一段落，你们若是有兴趣，欢迎在回复中进行讨论:)