Implementing Services and Business Processes using WCF and WF

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Implementing Services and Business
Processesusing WCF and WF

• Nenad Jovicic, B.Sc.Program Manager, Pexim
  Solutionsnenad.jovicic_at_pexim.co.yu

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Agenda

• SOA
• WCF Fundamentals
• WCF Demo
• WF
• WF Demo
• WF and WCF integration in Visual Studio 2008
• WF WCF integration demo
• Summary
• QA

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Services

• A service is a program you interact with via
  message exchanges
• Service implements business functionality
• Services are built to last
• Availability and stability are critical

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What is Service Orientation?

• Service Orientation is an approach to building
  systems using autonomous services which adhere to
  the 4 Principles of Service Orientation
• Boundaries are Explicit
• Services are Autonomous
• Services share schema and contract, not class
• Service compatibility is determined based on
  policy

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Service Design Key Concepts
Services
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Web Services ArchitectureRoadmap
Connected Applications
Security
Reliable Messaging
Transactions
Metadata
Messaging
XML
Transports
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WCF Fundamentals

• Today we develop distributed systems with big
  number of different technologies
• ASMX, .Net Remoting, Message Queueing, Enterprise
  services, WSE
• Software is connected and building connected
  systems is hard
• WCF simplifies development of connected systems

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WCF helps you

• You are typical husband with big problem
• Save your money and make your wife happy
• One shoe for all occasions

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Unified programming model
.NET Remoting
ASMX
Interop with other platforms
Extensibility Location transparency
Attribute- Based Programming
Message- Oriented Programming
WS- Protocol Support
Enterprise Services
System.Messaging
WSE
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WCF

• Windows Communication Foundation - formerly
  code-named "Indigo
• Connected systems platform for Windows
• It is a new breed of communications
  infrastructure built around the Web services
  architecture
• Windows Communication Foundation unifies a broad
  array of distributed systems capabilities in a
  composable and extensible architecture, spanning
  transports, security systems, messaging patterns,
  encodings, network topologies, and hosting
  models.
• Microsoft's unified programming model for
  building service-oriented applications

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WCF Architecture
Client
Service
Bv
Bv
Message
Bv
Bv
Address
Binding
Contract
(Where)
(How)
(What)
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ABC of Indigo
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ABC of Indigo

• Contract can support many bindings and binding
  can support many contracts
• Service can have more endpoints ( published
  contracts on address) at the same time
• HTTP, interoperability
• TCP, performances
• Contract can have specific binding requests like
  security, transaction flow, etc.
• If binding does not satisfy contract requirements
  it will not be started

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Decide which binding to use

• Bindings Transports Encoders Protocols
• Transports ( HTTP, TCP, Named Pipes, MSMQ, Peer
  Transport )
• Encoding
• Text (for interoperability)
• Binary ( for hi-speed Indigo-to-Indigo )
• MTOM (Message Transmission Optimization Protocol
• for incorporating binary attachments )
• Protocols (WS-Security, WS-Reliable Messaging,
  WS-Coordination and Transaction)

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Binding table
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WCF implements WS-

• Security
• Transactions
• Reliable messaging
• Metadata

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Security credentials

• Message Credentials
• Security requirements satisfied atmessage layer
• Claims carried in messages
• More credential types, extensible
• Transport Credentials
• Security requirements satisfied attransport
  layer
• Performance benefits
• Restricted claim types

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Defining Service

• Using System.ServiceModel
• ServiceContract
• interface IArrangementManagement
• OperationContract
• void Save(ArrangementRq request)

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WCF demo
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Fundamentals - What is Workflow?
A set of activities that coordinate people and /
or software...
EscalateToManager
CheckInventory
Example activities.
organized into a workflow.
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Windows Workflow Foundation
Extensible framework and tools for building
workflow into Windows applications

• Single workflow technology for Microsoft
  products, partners and customers
• A framework to build on not a server or
  application
• Key features
• Enables long running workflows in any application
  or server
• Extensible activity framework
• Unified model for human and system workflow
  scenarios
• Visual designer for graphical and code-based
  authoring
• Availability
• Exposed via .Net 3.5 and VS 2008

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Why Workflow Technology?
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Windows Workflow Foundation
Visual Designer

• Key Concepts

• Workflows are a set of Activities

A Workflow

• Workflows run within a Host Process any
  application or server

• Developers can build their own Custom Activity
  Libraries

An Activity
Custom Activity Library
Components

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

Windows Workflow Foundation

• Runtime Engine Workflow execution and state
  management

Base Activity Library

• Runtime Services Hosting flexibility and
  communication

Runtime Engine

• Visual Designer Graphical and code-based
  construction
• Rules Engine Enables declarative, rule-based
  development for workflows and any .NET
  application to use.

Runtime Services
Host Process
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Workflow Basics

• A workflow is a class, designer generated

public sealed partial class MyWorkflowSequentialW
orkflowActivity public MyWorkflow() Initia
lizeComponent()

• A workflow class may be defined in markup

lt?Mapping XmlNamespace"Activities"
ClrNamespace"System.Workflow.Activities"
Assembly"System.Workflow.Activities"
?gt ltSequentialWorkflow xClass"MyWorkflow"
xmlns"Activities" xmlnsx"Definition"gt
lt/SequentialWorkflowgt
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Workflow Authoring Modes
Markup and Code
Application Generated
Markup Only Declarative
Code Only
App creates activity tree and serializes

XAML
XAML

• Code creates
• workflow
• in constructor

• XML defines
• workflow
• Code-beside
• defines extra logic

• XML defines
• workflow structure
• logic and data flow

XAML
Workflow Compiler wfc.exe

• .NET assembly
• ctor defines
• workflow

C/VB Compiler
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Custom Activities

• Activities are the building blocks of workflows
• The unit of execution, re-use and composition
• Basic activities are steps within a workflow
• Composite activities contains other activities
  EG Sequence
• Base Activity Library provides out-of-the-box
  activity set
• Partners and customers author custom activities
  EG ExecutePaymentOrder

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Custom Activities

• Activities are classes
• Properties and events are defined by the activity
  author and programmable from workflows
• Has methods that are coded by the activity author
  but invoked by the workflow runtime (EG Execute)
  or designer
• Can be built into workflow assemblies or deployed
  as re-usable libraries

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Example A SendMail Activity
using System.Workflow.ComponentModel public
partial class SendMail System.Workflow.Component
Model.Activity public SendMail()
InitializeComponent() protected override
Status Execute(ActivityExecutionContext context)
// my logic here to send the
email return Status.Closed public
partial class SendMail public string
subject public string Subject get return
subject set this.subject value
private void InitializeComponent() // designer
generated this.ID "SendMail"

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Activities An Extensible Approach
Base Activity Library
Custom Activity Libraries
Out-of-Box Activities

• OOB activities, workflow types,
• base types
• General-purpose
• Activity libraries
• define workflow
• constructs

• Create/Extend/ Compose activities
• App-specific building blocks
• First-class citizens

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Base Activity Library
System Workflow
Human Workflow
Base Activity Library
Workflow Styles
State Machine Workflow
Sequential Workflow
Sequential Control
Rules-Driven
Transactions
Out-of-box Activities
Communications Local and Web Services
Activity Framework
Base Classes and Behaviors Dynamic Update
Exceptions Transactions
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Runtime Engine And Services
My workflow
Windows Workflow Foundation

• Base Activity Library

Host Process
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Developer Ecosystem
Workflow Developers
Minimal coding, full authoring environment
Application
Workflows
Flow Logic
Host Developers
Application services host
Custom Activities
WWF Runtime
Services
Custom Services
Activity Developers
Custom execution validation logic
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Runtime Services
Host Application
App Domain
Runtime
Services
TimerService manages timers e.g. Delay activity.
Out of Box Services are provided that support SQL
Server
TimerService
PersistenceService stores and retrieves instance
state.
SQL
PersistenceService
TrackingService
TrackingService manages profiles and stores
tracked information.
ThreadingService
TransactionService
Common resource services for managing threading
and creating transactions
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WF Demo
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WF and WCF integration inVisual Studio 2008

• Workflow Foundation does not provide a default
  hosting environment
• WorkflowServiceHost is a service-oriented hosting
  environment for Workflows
• ServiceContracts provide strongly-typed
  programming model for interacting with a Workflow
• Host uses messaging to interact with Workflow
• Workflow uses messaging to interact with host

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Workflow Service Architecture
Workflow.cs or Workflow.xoml
Workflow Runtime
WorkflowOperationInvoker
App.config
ServiceHost
Workflow ServiceHost
DurableInstanceProvider
MessageContextInspector
ContextChannel
ListenerChannel
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WF WCF integration
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Summary

• Service and business processes can be easily
  developed using WCF and WF
• WCF implements WS-
• Business Activity library can be easily developed
  using WF
• WF and WCF are integrated in VS 2008

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Resources

• http//netfx3.com/

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QA

• Its time for challenge www.pexim.net/ucc2008
• Prize?

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