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. Existing build technologies Motivation for new way of building software • Objectives • Visual Configuration (script free) • Real-time distributed feedback • Parallel Task processing • Cheap

5. Promise of Windows Workflow Foundation Possibilities that WF provides • Design by markup • Access to high level programming language • Threading, tracing, events • End user configuration

6. Promise of Windows Workflow Foundation The Four Workflow Tenants: • Co-ordinate work performed by people and software • Long-running and stateful • Based on extensible models • Transparent and dynamic throughout their life cycle

7. Promise of Windows Workflow Foundation Motive for a Dynamic Build process • Build technologies • New software development technologies and platforms • Configuration

8. Promise of Windows Workflow Foundation Scenario Start Checkout ConfigMode = Release? Compile in Release configuration Compile in Debug configuration Deploy Stop

9. Promise of Windows Workflow Foundation Build script encapsulation demo • Reuse of existing scripts and build technologies • Example of a code only workflow

10. Promise of Windows Workflow Foundation Authoring Modes Full Visual Studio Support • Code Only • Markup (XAML) + Compiled Code Beside Some Visual Studio Support + Prayer • Markup + Assembly binding

11. Workflow Customization Custom Activities • Part of Workflow tenants (Based on extensible models) • Reusable components • Possibility of Software Build DSL

12. Workflow Customization Domain Specific Language • 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 • DSL’s address business concerns (Higher level level of abstraction)

13. Workflow Customization Domain Specific Language • DSL’s typically come with a code generation tool • Constraint syntax • Accessible to non-developers

14. Workflow Customization Domain Specific Language • May require a Parser • Schemas help to validate instructions • Algorithm Syntax - what is being said – is limited

15. Workflow Customization Domain Specific Language • 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. Workflow Customization Custom Workflow DependencyObject <abstract> Activity MyCustomActivity CompositeActivity SequenceActivity SequentialWorkflowActivity MyCustomWorkflow System.Workflow.ComponentModel

17. Workflow Customization Activity Class DependencyObject <abstract> • Methods to override: • Execute • Cancel • Initialize • These are called by the WF runtime – not manually Activity Execute(ActivityExecutionContext):ActivityExecutionContext Cancel(ActivityExecutionContext):ActivityExecutionContext Initialize(IServiceProvider)

18. Workflow State Activity Class State Initialized Executing Canceling Closed Faulting Compensating

19. Workflow State Dependency Object & Dependency Properties DependencyObject <abstract> • Activity data storage mechanism • Allows activities to project their properties onto their children • Essential provision for WF tenent (Long-running and stateful)

20. Workflow State Dependency Object • 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. Workflow State Dependency Properties • Must derive from DependencyObject • Register property then define property

22. Workflow State Dependency Properties public static DependencyProperty MyDepPropProperty= DependencyProperty.Register( “MyDepProp", typeof(String), typeof(MyClass) ); Property name Property Type Owner Type

23. Workflow State Dependency Properties public StringCompilationMode{get { return(String)(base.GetValue(MyClass. MyDepPropProperty)); } set { base.SetValue(MyClass.MyDepPropProperty,value); } }

24. Workflow State Parameter Passing Dictionary<String, Object> Args = new Dictionary<string, object>(); Args.Add("RepositorySource", "C:\\Projects\\BuildManager\\Repository"); Args.Add("CompilationMode", "Release"); Args.Add("Application", "C:\\Projects\\BuildManager\\Checkout\\BuildMeWinApp\\BuildMeWinApp.sln"); Args.Add("Target", "C:\\Projects\\BuildManager\\BuildTarget"); WorkflowInstance instance = workflowRuntime.CreateWorkflow(typeof(BuildTasks.Builder), Args);

25. Custom Workflow Build custom workflow demo • Domain specific activities • Domain specific workflow • Example of Code+Markup workflow

26. Authoring Modes Markup <SequentialWorkflowActivityx:Class="MarkupBuild.Build" x:Name="Build" xmlns:ns0="clr-namespace:BuildTasks;Assembly=BuildTasks, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/workflow"> <ns0:CheckoutBuildFile="{x:Null}" x:Name="checkout1" RepositorySource="{x:Null}" /> <ns0:CompileBuildFile="{x:Null}" x:Name="compile1" CompilationMode="{x:Null}" Application="{x:Null}" /> <ns0:DeployBuildFile="{x:Null}" x:Name="deploy1" CompilationMode="{x:Null}" Target="{x:Null}" /> </SequentialWorkflowActivity>

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

28. Authoring Modes Binding <SequentialWorkflowActivityx:Class="MarkupBuild.Build" x:Name="Build" xmlns:ns0="clr-namespace:BuildTasks;Assembly=BuildTasks, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/workflow"> <ns0:Checkoutx:Name="checkout1" RepositorySource="{ActivityBind Build,Path=RepositorySource}" /> <ns0:Compilex:Name="compile1" CompilationMode="{ActivityBind Build,Path=CompilationMode}" Application="{ActivityBind Build,Path=Application}" /> <ns0:Deployx:Name="deploy1" Target="{ActivityBind Build,Path=Target}" CompilationMode="{ActivityBind Build,Path=CompilationMode}" /> </SequentialWorkflowActivity>

29. Authoring Modes Binding • 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. Authoring Modes Markup-only workflows • 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. Serialization Deserialization • 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(typeof(SharedWorkflows.MarkupOnlyBaseWorkflow).Assembly); container.AddService(typeof(ITypeProvider), provider); Add ServiceContainer with the TypeProvider to serialization manager DesignerSerializationManager dsm = new DesignerSerializationManager(container); XmlReader xmlReader = XmlReader.Create(fileName) WorkflowMarkupSerializer markupSerializer = new WorkflowMarkupSerializer(); workflow = markupSerializer.Deserialize(dsm, xmlReader) as Activity;

35. Designer Re-Hosting • Code generation tool • Configurable by end user

36. Designer Re-hosting Introduction • 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 BeginLoad method MyDesignerLoader: WorkflowDesignerLoader IDesignerHost Persisted Workflow Models (.xoml files) GetView method WorkflowView

39. Designer Re-hosting Property Attributes • Description • Category • Browsable • DesignerSerializationVisibility

40. Designer Re-hosting WorkflowDesignerLoader • 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 it’s 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

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