Building you build process with Windows Workflow Foundation

1
Building you build process with Windows Workflow
Foundation

• Abid Quereshi

2
Agenda

• Existing build technologies
• Promise of Workflow Foundation
• Demonstration reusing Nant scripts
• Demonstration - Custom Task
• Authoring Modes
• Serialization and Deserialization
• Designer Re-Hosting

3
Existing build technologies

• Cruise Control
• MS Build
• Nant/Ant
• Visual Build
• Automated Build Studio
• DB Change management tools (DB Ghost,
  Embarcadero)
• Make files, batch files, any other

4
Motivation for new way of building software
Existing build technologies

• Objectives
• Visual Configuration (script free)
• Real-time distributed feedback
• Parallel Task processing
• Cheap

5
Possibilities that WF provides
Promise of Windows Workflow Foundation

• Design by markup
• Access to high level programming language
• Threading, tracing, events
• End user configuration

6
The Four Workflow Tenants
Promise of Windows Workflow Foundation

• Co-ordinate work performed by people and software
• Long-running and stateful
• Based on extensible models
• Transparent and dynamic throughout their life
  cycle

7
Motive for a Dynamic Build process
Promise of Windows Workflow Foundation

• Build technologies
• New software development technologies and
  platforms
• Configuration

8
Scenario
Promise of Windows Workflow Foundation
Start
Checkout
ConfigMode Release?
Compile in Release configuration
Compile in Debug configuration
Deploy
Stop
9
Build script encapsulation demo
Promise of Windows Workflow Foundation

• Reuse of existing scripts and build technologies
• Example of a code only workflow

10
Authoring Modes
Promise of Windows Workflow Foundation
Full Visual Studio Support

• Code Only
• Markup (XAML) Compiled Code Beside

Some Visual Studio Support Prayer

• Markup Assembly binding

11
Custom Activities
Workflow Customization

• Part of Workflow tenants (Based on extensible
  models)
• Reusable components
• Possibility of Software Build DSL

12
Domain Specific Language
Workflow Customization

• Limited form of computer language designed for a
  specific class of problems.
• Library(Framework) Configuration (Process,
  algorithm or how to perform a process)
• Most Frameworks in a particular platform address
  technical concerns
• DSLs address business concerns (Higher level
  level of abstraction)

13
Domain Specific Language
Workflow Customization

• DSLs typically come with a code generation tool
• Constraint syntax
• Accessible to non-developers

14
Domain Specific Language
Workflow Customization

• May require a Parser
• Schemas help to validate instructions
• Algorithm Syntax - what is being said is
  limited

15
Domain Specific Language
Workflow Customization

• Algorithm Syntax - what is being said is
  limited
• How it is being said may take two forms
• Internal DSL - syntax of instruction is a subset
  of host general purpose language code
• External DSL often a configuration file

16
Custom Workflow
Workflow Customization
DependencyObject ltabstractgt
Activity
MyCustomActivity
CompositeActivity
SequenceActivity
SequentialWorkflowActivity
MyCustomWorkflow
System.Workflow.ComponentModel
17
Activity Class
Workflow Customization
DependencyObject ltabstractgt

• Methods to override
• Execute
• Cancel
• Initialize
• These are called by the WF runtime not manually

Activity
Execute(ActivityExecutionContext)ActivityExecuti
onContext Cancel(ActivityExecutionContext)Activi
tyExecutionContext Initialize(IServiceProvider)
18
Activity Class State
Workflow State
Initialized
Executing
Closed
Faulting
Canceling
Compensating
19
Dependency Object Dependency Properties
Workflow State
DependencyObject ltabstractgt

• Activity data storage mechanism
• Allows activities to project their properties
  onto their children
• Essential provision for WF tenent (Long-running
  and stateful)

20
Dependency Object
Workflow State

• Hash table
• Essential provision for WF tenant (Long-running
  and stateful)
• Add a public static instance of Dependency
  Property to manage that property for all
  instances of the activity
• Implement .NET Property that accesses an
  activities Dependency Property

21
Dependency Properties
Workflow State

• Must derive from DependencyObject
• Register property then define property

22
Dependency Properties
Workflow State
public static DependencyProperty
MyDepPropProperty DependencyProperty.Register(
MyDepProp", typeof(String),
typeof(MyClass) )
Property name
Property Type
Owner Type
23
Dependency Properties
Workflow State
public String CompilationMode get
return (String)(base.GetValue(MyClass.
MyDepPropProperty)) set
base.SetValue(MyClass.MyDepPropProperty, value)


24
Parameter Passing
Workflow State
DictionaryltString, Objectgt Args new
Dictionaryltstring, objectgt() Args.Add("Repositor
ySource", "C\\Projects\\BuildManager\\Repository"
) Args.Add("CompilationMode", "Release")
Args.Add("Application", "C\\Projects\\BuildManage
r\\Checkout\\BuildMeWinApp\\BuildMeWinApp.sln") A
rgs.Add("Target", "C\\Projects\\BuildManager\\Bui
ldTarget") WorkflowInstance instance
workflowRuntime.CreateWorkflow(typeof(BuildTasks.B
uilder), Args)
25
Build custom workflow demo
Custom Workflow

• Domain specific activities
• Domain specific workflow
• Example of CodeMarkup workflow

26
Markup
Authoring Modes
ltSequentialWorkflowActivity xClass"MarkupBuild.B
uild" xName"Build" xmlnsns0"clr-namespaceBu
ildTasksAssemblyBuildTasks, Version1.0.0.0,
Cultureneutral, PublicKeyTokennull"
xmlnsx"http//schemas.microsoft.com/winfx/2006
/xaml" xmlns"http//schemas.microsoft.com/winfx/2
006/xaml/workflow"gt ltns0Checkout
BuildFile"xNull" xName"checkout1"
RepositorySource"xNull" /gt ltns0Compile
BuildFile"xNull" xName"compile1"
CompilationMode"xNull" Application"xNull
" /gt ltns0Deploy BuildFile"xNull"
xName"deploy1" CompilationMode"xNull"
Target"xNull" /gt lt/SequentialWorkflowActivitygt
27
XOML
Authoring Modes

• Extensible Orchestration Markup Language (XOML)
  files, a special case of XAML file types, which
  specify the workflow logic within an application.

28
Binding
Authoring Modes
ltSequentialWorkflowActivity xClass"MarkupBuild.B
uild" xName"Build" xmlnsns0"clr-namespaceBu
ildTasksAssemblyBuildTasks, Version1.0.0.0,
Cultureneutral, PublicKeyTokennull"
xmlnsx"http//schemas.microsoft.com/winfx/2006
/xaml" xmlns"http//schemas.microsoft.com/winfx/2
006/xaml/workflow"gt ltns0Checkout
xName"checkout1" RepositorySource"ActivityBind
Build,PathRepositorySource" /gt ltns0Compile
xName"compile1" CompilationMode"ActivityBind
Build,PathCompilationMode" Application"Activit
yBind Build,PathApplication" /gt ltns0Deploy
xName"deploy1" Target"ActivityBind
Build,PathTarget" CompilationMode"ActivityBind
Build,PathCompilationMode" /gt lt/SequentialWorkf
lowActivitygt
29
Binding
Authoring Modes

• gives a dependency property an ActivityBind
  object to evaluate when asked for its value
• ActivityBind can point to other fields,
  properties, or methods of activities inside a
  workflow.
• One activity could bind its input properties to a
  previous activity's outputs.
• Binding makes the data flow a part of the
  workflow model.

30
Markup-only workflows
Authoring Modes

• Allows for declarative programming
• Facilitates the highest degree of encapsulation
• Facilitates usage of code-generation tool
• Requires mechanism to serialize and deserialize
  WF

31
Serialization
Serialization

• Serialization
• Create a XAML workflow markup file from an
  in-memory workflow model
• Deserialization
• Reads markup and creates in-memory object
  containing definition of workflow model

32
Serialization
Serialization
private static void SerializeToMarkup(Activity
workflow, String fileName) try
using (XmlWriter xmlWriter
XmlWriter.Create(fileName))
WorkflowMarkupSerializer mrkupSerializer new
WorkflowMarkupSerializer()
mrkupSerializer.Serialize(xmlWriter, workflow)
catch (Exception e)
Console.WriteLine("Exception during
serialization 0" e.Message)
33
Deserialization
Serialization

• Deserializer needs knowledge of the types
  referenced in the markup
• ServiceContainer, TypeProvider,
  DesignSerializationManager

34
Serialization
Activity workflow null ServiceContainer
container new ServiceContainer() Add a
TypeProvider to resolve BuildTask
references TypeProvider provider new
TypeProvider(container) provider.AddAssembly(type
of(SharedWorkflows.MarkupOnlyBaseWorkflow).Assembl
y) container.AddService(typeof(ITypeProvider),
provider) Add ServiceContainer with the
TypeProvider to serialization manager DesignerSer
ializationManager dsm new DesignerSerializationM
anager(container) XmlReader xmlReader
XmlReader.Create(fileName) WorkflowMarkupSerialize
r markupSerializer new WorkflowMarkupSerializer(
) workflow markupSerializer.Deserialize(dsm,
xmlReader) as Activity
35
Designer Re-Hosting

• Code generation tool
• Configurable by end user

36
Introduction
Designer Re-hosting

• The logic of a build process is often simple
  enough for to allow drag and drop process design
  by non-developers
• WF allows for re-hosting the workflow designer in
  a windows application (outside of the Visual
  Studio environment)
• Powerful proposition

37
Designer Classes

• System.ComponentModel.Design.DesignSurface
• General-purpose design canvas
• System.Workflow.ComponentModel.Design.
• WorkflowDesignerLoader
• Serialization/Deserialization
• Loading of services used by the designer
• System.Workflow.ComponentModel.Design.WorkflowView
  
• Implements visual representation of your workflow
  model

38
Designer Classes
Design Surface
Load services and populate visual tree
IRootDesigner
GetServices method
GetDesigner method
MyDesignerLoader WorkflowDesignerLoader
BeginLoad method
IDesignerHost
Persisted Workflow Models (.xoml files)
GetView method
WorkflowView
39
Property Attributes
Designer Re-hosting

• Description
• Category
• Browsable
• DesignerSerializationVisibility

40
WorkflowDesignerLoader
Designer Re-hosting

• Abstract
• Must be implemented in a derived class
• Responsible for loading workflow from peristable
  tore .xoml and populating tree of visual objects
  in the designer and Vise-Versa

41
Designer Re-hosting

• Services
• IMenuCommandService
• ITypeProvider
• IToolboxService
• IPropertyValueUIService
• IEventBindingService

42
Designer Re-hosting

• Demo
• Simple workflow
• Workflow with conditional branch

43
Conclusion

• Revisiting Objectives
• Visual Configuration (script free)
• Real-time distributed feedback
• Parallel Task processing
• Cheap

44
Conclusion

• Real-time distributed feedback
• Limitation is due to fact that WF Markup is a
  subset of XAML the markup parser is not
  extensible
• Parallel Task processing
• Parallel task activity is not multithreaded
• This can be implemented but its not out-of-the
  box functionality

45
Conclusion

• References
• Pro WF Windows Workflow in .NET 3.0, Apress,
  Bruce Bukovics
• Professional Windows Workflow Foundation, Wrox,
  Todd Kitta
• Introduction to Domain Specific Languages, Martin
  Fowler, http//www.infoq.com/presentations/domain-
  specific-languages

46
Blank Slide
Serialization