Introducing Windows Workflow Foundation

Understanding Windows Workflow Foundation

Janakiram MSV

Developer Evangelist

Microsoft Corporation

Introducing Windows Workflow Foundation

Agenda

• Architecture & Concepts

• Workflow Styles

• Summary

• WPF-Windows Presentation Foundation– XAML– XAMLPad, Expression Editor, VS Designer

• CardSpace• WCF-Windows Communication Foundation• WF-Workflow Foundation• Orcas

– .NET 3.0 Visual Studio Extensions

.Net Framework 3.0

Power of Flow Chart

• Maintainability is expensive

• Code is opaque

• Modules are hard-wired

Flowchart Scenarios

• Document Life Cycle Management

• LOB Application Workflow

• Business Process Management

• UI Navigation Logic

public void PlaceNewOrder(Employee e, Product p){ if(e.FTE) switch(p.Category) {

case “Computer”: if (GetManagerApproval(e,p)) {

Inventory i=InventoryServiceProxy.GetInventory(P.ProductID);if(i.InStock){ PurchaseOrder PO=new PurchaseOrder(p,1); OrderAck Ack=OrderServiceProxy.SendPO(PO); SendMail(

“Placed New Order”, ”Order #” + Ack.OrderNo+” Expected on ”+ ACK.ShipDate, e.EmailID );}

}……………………………………………….……………………………………………….

}

Yet Another Component….

Today’s Application Development

FormsForms

DataData

ApplicationApplicationlogiclogic

Rules andRules andpoliciespolicies

ApplicationApplicationcodecode

Workflow Workflow modelmodel

ServiceServicess

What is Workflow?

• Dictionary.com Definition– The flow or progress of work done by a

company, industry, department, or person. – The rate at which such flow or progress takes

place

Tenets of Workflow

Workflows coordinate work performed by people and by software

Workflows are long running and stateful

Workflows are transparent and dynamic through their lifecycle

Workflows are based on extensible models

Introducing Windows Workflow Foundation

• Provide a singular engine for workflow execution for all applications built on the Windows platform

• Supports a wide range of scenarios

• Bring model-driven workflow development to the entire .NET development community

• Enable reusable workflow component development to ensure both developers and ISVs can deeply embed this technology in their applications.

Windows Workflow Foundation

Key Concepts

Host Process

WindowsWorkflow Foundation

Runtime Engine

A Workflow

An Activity

Runtime Services

Base Activity Library

Custom Activity Library

Visual Designer

• Visual Designer: Graphical and code-based construction

• Workflows are a set of Activities

• Workflows run within a Host Process: any application or server

• Developers can build their own Custom Activity Libraries

Components

• Base Activity Library: Out-of-box activities and base for custom activities

• Runtime Engine: Workflow execution and state management

• Runtime Services: Hosting flexibility and communication

Workflow Basics

• A workflow is a class

• A workflow class may be defined in markup

<?Mapping XmlNamespace="Activities" ClrNamespace="System.Workflow.Activities" Assembly="System.Workflow.Activities" ?>

<SequentialWorkflow x:Class="MyWorkflow" xmlns="Activities" xmlns:x="Definition"> …</SequentialWorkflow>

using System.Workflow.Activities;

public class Workflow1 : SequentialWorkflow{}

Workflow Basics

• Workflow constructor configures contained activities (like forms & controls)

using System.Workflow.Activities;public partial class Workflow1 : SequentialWorkflow {

public Workflow1() {

InitializeComponent();}

}

public sealed partial class Workflow1 : SequentialWorkflow {private Delay delay1;private void InitializeComponent()

{this.delay1 = new System.Workflow.Activities.Delay();this.delay1.ID = “delay1";this.delay1.TimeoutDuration =

System.TimeSpan.Parse("00:00:05");this.Activities.Add(this.delay1);this.ID = "Workflow1";

}}

Demo

Order Workflow

Workflow Composition

What are Activities?

• An activity is a step in a workflow– Has properties and events that are

programmable within your workflow code– Has methods (e.g. Execute) that are only

invoked by the workflow runtime

• Think of Forms & Controls– Activity == Controls– Workflows == Forms

• Activities fall under two broad categories– Basic – steps that “do work”– Composite – manage a set of child activities

Activities: An Extensible Approach

– OOB activities,workflow types,base types

– General-purpose– Activity libraries define workflow

constructs

– Create/Extend/Compose activities

– App-specificbuilding blocks

– First-class citizens

Base Activity

Library

Custom ActivityLibraries

Author new activity

Base ActivityLibrary

Extend activity

Compose activities

– Vertical-specificactivities & workflows

– Best-practice IP &Knowledge

Domain-SpecificWorkflow Packages

Compliance

RosettaNet

CRM

IT Mgmt

Flexible Control Flow

Rules-driven Activities

Step2

Step1Rule1Rule1

Rule2Rule2

DataRules + data statedrive processing order

•Data-driven•Simple Conditions, complex Policies •Constrained Activity Group

State Machine Workflow

State2

State1EventEvent

EventEvent

External events drive processingorder

•Reactive, event-driven•Skip/re-work, exception handling•Graph metaphor

Sequential WorkflowStep1

Step2

Sequentialstructure prescribesprocessing order

•Prescriptive, formal•Automation scenarios•Flowchart metaphor

Summary

• A single workflow technology for Windows– Platform level workflow framework for use within Microsoft products & ISV

applications– Will be used by BizTalk Server, Office 2007 MBS & other Microsoft client/server

products– Available to all Windows customers

• Microsoft is redefining workflow– Unified technology for System & Human workflow– Multiple styles: sequential, rules-based, state machine– Supports dynamic interaction

• Microsoft is taking workflow mainstream– Consistent and familiar programming model for reaching mainstream application

developer– Available to millions of end-users through Office 2007– Extensible platform for ISVs

Resources

• http://wf.netfx3.com

• http://msdn.microsoft.com/winfx

• http://www.microsoft.com/seminar

Janakiram.msv@microsoft.com

Questions

Microsoft Windows Vistawww.microsoft.com/windowsvista/