Build Process Driven Applications with WF

Transcription

1 Build Process Driven Applications with WF Brian Noyes IDesign Inc. All rights reserved About Brian Microsoft Regional Director / Solution Architect MVP Writing Data Binding in Windows Forms 2.0, Addison-Wesley, January 2006 Smart Client Deployment with ClickOnce, Addison-Wesley, Fall 2006 MSDN Magazine, CoDe Magazine, The Server Side.NET, asp.netpro, Visual Studio Magazine Speaking Microsoft TechEd US, Europe, Malaysia, Visual Studio Connections, DevTeach, DevEssentials, VSLive!, INETA Speakers Bureau, MSDN Webcasts Participate in Microsoft design reviews brian.noyes@idesign.net Blog: 1

2 About INETA Who are we (INETA)? How long have we been around since 2002 What do we do? Sponsor user groups speakers (58 well known industry leaders), food, software, swag How big is INETA? (860+ Groups worldwide; 810,000 members) North America : U.S. (211 groups, 116,500 members) Canada (25 groups, 14,000 members) Who pays for it sponsors (major sponsor is Microsoft, but new additional sponsors being solicited and welcome!) INETA needs volunteers Benefit your User Group and yourself by getting involved INETA Web Site: Workflow Overview Workflows describe a business process A set of activities that define a process People or processing Workflows control processing Activity activation Transition between activities (control flow) Activity deactivation 2

3 Workflow Overview Workflows are Described graphically Long running Stateful Workflow Application Examples Line of business applications Supply chain automation Sales management IT Management Document processing New employee provisioning Trouble ticket / bug tracking.net Development Page / View flow Business logic processing 3

4 Windows Workflow Foundation Single workflow technology for the Windows platform SDK / Framework for building workflow applications Abstraction of real world processes Makes workflow technology accessible to all.net developers WF Overview Built on top of CLR /.NET Framework BCL Integrate workflow capabilities into.net applications Human Workflows through System Workflows Enable development of process-oriented applications / logic Can build without WF WF makes development process more intuitive WF makes resulting logic more maintainable Low level API / engine Provides capabilities previously only available in BizTalk 4

5 WF Availability / Platforms Part of.net 3.0 Supported on Windows Vista, XP SP2, Server 2003 Releases with Windows Vista in November 2006 Need Visual Studio 2005 (non-express) for IDE integrated development Ships with / used by Office 2007 as well Why not WWF? WF Relation to Other Technologies BizTalk 2004 / 2006 Packaged workflow application server Managed environment for defining, running, and managing orchestrations (workflows) and activities Business activity monitoring and management Message transformation engine BizTalk 20XX WF replaces orchestration engine Office 2007 End user (Word, Excel, Access, etc.) Web developer (FrontPage, SharePoint services) App developer (Visual Studio, SharePoint services) Third Part Products (Ultimus, K2, etc.) 5

6 WF Design Process Define Workflows Visual Studio designer XAML code Code-behind Add / connect / configure Activities Integrate into applications Windows, Web Site, Services WF Layers 6

7 WF Hosting Model One WF runtime instance per AppDomain Loaded once Any application process can host Windows Forms ASP.NET Console Windows Service Windows Activation Service WF Types Sequential Workflows Structured, step-by-step process flows Transitions from activity to activity Have a beginning and an end May run forever Can (should?) be complex Branches / Loops / Delays Parallel activity I/O anywhere in workflow Human activities 7

8 WF Types State Machine Workflows System transitions from one state to another based on events Transitions based on arbitrarily complex conditions / events States can nest Base Activity Library Control flow Conditional Looping Events Parallel Delay 8

9 Base Activity Library Communications Data communications with host Web services Transaction / Exceptions Throw / Handle Compensate Suspend / Terminate Code Anything else Runtime Engine Execution Scheduling Rule invocation Tracking events Lifecycle management State management / persistence Activation 9

10 Workflow Services Persistence Read/Write of workflow state (activation / deactivation) SQL Server provider in the box Timer Scheduled execution of activities In memory and SQL Server based timers in the box Threading Thread pools (.NET / ASP.NET) Tracking persistence SQL Server and Event Log in the box Communications Raw I/O through framework libraries Workflow Basics A workflow is an instance of a class Constructor initializes contained activities (like Windows Forms and contained controls) public sealed partial class MyWorkflow : SequentialWorkflowActivity { public MyWorkflow() { // Initialize activity properties and events InitializeComponent(); } } Can be defined in markup <SequentialWorkflowActivity x:class="workflowconsoleapplication2.workflow3" Name="MyWorkflow" xmlns=" xmlns:x=" </SequentialWorkflowActivity> 10

11 Activity Basics Activities are classes Properties and events Defined by the activity author Invoked by the runtime during workflow execution Methods Defined by the activity author Invoked by the runtime or designer Activities: An Extensible Approach Base Activity Library Custom Activity Libraries Domain-Specific Workflow Packages Compliance Out-of-Box Activities Compose activities Author new activity Extend activity RosettaNet CRM IT Mgmt OOB activities, workflow types, base types General-purpose Activity libraries define workflow constructs Create/Extend/ Compose activities App-specific building blocks First-class citizens Vertical-specific activities & workflows Best-practice IP & Knowledge 11

12 Runtime Transparency Object types decoupled for services / instance creation Factories Providers Attributes Interface-based programming Plug in model Dynamic updates Modify the workflow while it is running Rule engine Dynamic decisions in activities Starting Workflow Runtime One instance per AppDomain static void Main(string[] args) { using(workflowruntime workflowruntime = new WorkflowRuntime()) { // Initialize the runtime // Start the runtime workflowruntime.startruntime(); // Do whatever else the main app needs to do... } } 12

13 Creating a Workflow Instance Factory method on workflow runtime: WorkflowInstance instance = workflowruntime.createworkflow(typeof(myworkflow)); instance.start(); Creating a Workflow Instance Creating and starting a workflow instance starts the runtime static void Main(string[] args) { using(workflowruntime workflowruntime = new WorkflowRuntime()) { AutoResetEvent waithandle = new AutoResetEvent(false); WorkflowInstance instance = workflowruntime.createworkflow( typeof(orderworkflow)); instance.start(); } } waithandle.waitone(); 13

14 Workflow Events Workflow lifetime events for every lifetime transition Can hook for monitoring, prompting, cleanup Lifecycle events: WorkflowCreated WorkflowStarted WorkflowIdled WorkflowSuspended WorkflowPersisted WorkflowLoaded WorkflowResumed WorkflowTerminated WorkflowAborted WorkflowCompleted WorkflowUnloaded Workflow Execution Determined by scheduler Default scheduler based on the managed thread pool Each workflow instance given thread from pool Executes on that thread until suspended May resume execution on a different thread 14

15 Adding Workflow Services Create runtime Call AddService on runtime instance Start runtime using(workflowruntime workflowruntime = new WorkflowRuntime()) { ExternalDataExchangeService dataservice = new ExternalDataExchangeService(); workflowruntime.addservice(dataservice); TradeService trades = new TradeService(); dataservice.addservice(trades); } workflowruntime.startruntime(); Can add services after runtime is started Communications Options Input / Output Parameters External Data Exchange Model Web Service Request / Response / Fault Code Activity Data access WCF Whatever you want (sockets, carrier pigeon, etc.) Note: Data activities (SelectData, WaitForQuery, etc.) were removed in Beta 2 and will not be in the released version. 15

16 Passing Data Into Workflow Define interface Events of type EventHandler<T> for calls into workflow T must derive from ExternalDataEventArgs Add ExternalDataExchange attribute to interface Define serializable ExternalDataEventArgs derived class to define data values to pass into workflow Create class that implements interface in host [Serializable] public class ToggleStateEventArgs : ExternalDataEventArgs {... } [ExternalDataExchange] public interface IToggleState { event EventHandler<ToggleStateEventArgs> ToggleState; } public class ToggleStateHelper : IToggleState {... } Workflow Summary Long running, stateful, transacted workflows in any app Flexible control flow - address human and system activities Extensible activity framework Visual designer for easy design and maintenance Runtime transparency 16

17 Resources IDesign WF Master Class (3 and 5 day versions) Will Work For Process Even Workflows Need a Place to Run, Brian Noyes, The Server Side.NET, August Manage Application Processes with Windows Workflow Foundation, Brian Noyes, The Server Side.NET, March 2006, es Windows Workflow Foundation, Dino Esposito, MSDN Magazine, March 2006, Windows Workflow Foundation, Dino Esposito, MSDN Magazine, April 2006, Presenting Windows Workflow Foundation, Sams Publishing, brian.noyes@idesign.net Blog: 17