The document summarizes a presentation on T4 templates and code generation. T4 templates allow generating code and other text-based assets from models. Templates contain text blocks, code blocks, and other features. Debugging and customizing T4 templates is covered. The use of T4 templates in Visual Studio for item templates and project templates is demonstrated. Resources for learning more about T4 templates are provided.

1. T4 / Code GenerationPresented by Joubin Najmaie (@codekindler)February 23, 2011Kitchener .NET UG: @cttdnug

2. AgendaWho am I?Motivations Behind Using T4T4 SyntaxDebugging T4 TemplatesBreakCustom T4 Host using GAXCompiling Generated CodeT4 Item TemplatesVS 2010 Item/Project TemplatesResourcesQ&A

3. Who am I?Technical Architect at one of the largest IT solution companies in North AmericaProject: www.pagefragments.comBlog: www.codekindler.comTwitter: @codekindlerEmail: joubin.najmaie@gmail.comWho am I?

4. Motivations Behind Using T4What is T4?Text Template Transformation ToolkitTransformation engineVehicle to Generates code from described modelsModels could beVisualClass diagramsERDs, Entity FrameworkText-basedXSDMetadata

5. Motivations behind using T4Why T4 is important?Developer guidance + speedNot limited to code: any text-based assetDocumentation generationScaffolding applicationsORMsDomain Specific DevelopmentExtending Visual StudioItem TemplatesIncluding latest ASP.NET MVC Controller and View templatesProject Templates

6. Motivations Behind Using T4How I got to work with T4Consultancy work – worked on a PoC migration of a static site to a content managedwith 1000+ pagesWorked with a couple of CMSs – SharePoint, Sitecore and an in-house CMS at an agency firmPatterns started emergingCreate fragments of a site that are most needed to be managed more regularly than others by different ownersThe fragments in the system are compiled and included using T4Addressing shortcomings and pains of CMSs

7. T4 Syntax

8. T4 SyntaxAnatomy of T4 templates

9. T4 SyntaxText Templating ‘workflow’

10. T4 SyntaxProcessing Directives Similar to ASPX or ASCX <#@ and end with #> Directives template assembly import output include

11. T4 Syntaxtemplate directive <#@ template debug="true" language="C#" #> Parametersdebuglanguageinheritshostspecific

12. T4 Syntaxtemplate directive parametersdebug parameterSystem %TEMP% folderlanguage parameterValues: C#, VB, C#3.5inherits parameterTells which base class to usehostspecific parameterA reference to the object that the hosts the engine.e.g. Host.TemplateFileHost.StandardAssemblyReferences

13. T4 Syntaxassembly directive<#@ assembly #> Parameter name could be an assembly in the GAC<#@ assembly name=“System.Data” #> absolute path to the assembly<#@ assembly name=“c:\projects\proj1\bin\debug\proj1.dll” #>

14. T4 Syntaximport directive <#@ import #> ParameternamespaceE.g. <#@ import namespace=“System.Collections.Generic” #>

15. T4 Syntaxinclude directive <#@ include #> Parameter file e.g. <#@ include file=“includedfile.tt” #>

16. Demodirectives

17. T4 SyntaxOn to T4 blocks

18. T4 SyntaxT4 Blocks Text blocks Code blocks Statement Expression Class feature

19. T4 SyntaxText BlocksNon-programmatic plain text

20. T4 SyntaxStatement Blocks Delineated using <# #>

21. T4 SyntaxExpression Blocks Delineated using <#= #>

22. T4 SyntaxClass Feature Blocks Delineated using <#+ #> Add any class level constructHelper functionsFieldsConstantsProperties

23. DemoT4 Blocks

24. Debugging T4 TemplatesDebuggingInsert System.Diagnostics.Debugger.Launch(); anywhere in the code blocks

25. DemoDebugging T4 Templates

26. Break ?

27. Custom T4 Host using GAXCustom T4 Host Guidance Automation Extensionshttp://bit.ly/fW99Zh Add references in VSMicrosoft.Practices.RecipeFramework.VisualStudio.LibraryMicrosoft.VisualStudio.TextTemplating

28. DemoCustom T4 Host

29. DemoCompile Generated Code

30. T4 Item TemplatesVS T4 Item Templates Text TemplateTextTemplatingFileGeneratorPreprocessed Text TemplateTextTemplatingFilePreprocessor Redistributing T4 engine with your app

31. DemoT4 Item Templates

32. VS 2010 Item/Project TemplatesVS Item TemplatesSingle file versus multi-file templatesAs .vsi/.zipVS 2010/{vs.net folder}/common7/ide/itemtemplates/{user folder}\Visual Studio 2010\Templates\ItemTemplatesTemplate parametersWhen the template wizard runs they are replaced

33. VS 2010 Item/Project TemplatesParameters to a VS template fileComplete list of all parameters: http://bit.ly/hJayFX

34. VS 2010 Item/Project TemplatesVS Template files Single File Template Multi-File Template

35. DemoVS 2010 Item/Project Templates

36. CTAsTry out the Text Template item templateStart thinking of scenarios where you can apply Domain Specific DevelopmentLook at other solutions that have used this development patternMany on Codeplex.com

37. ResourcesWhere to go for resources?Code Generation and Text Templates (T4)http://bit.ly/eJL91tT4 Templates: A Quick-Start Guide for ASP.NET MVC Developershttp://bit.ly/cVKYp5Language Oriented Programming: The Next Programming Paradigm:http://bit.ly/bVqYoGCodePlex: http://bit.ly/i0VnHKBookDomain-Specific Development with Visual Studio DSL ToolsISBN: 0321398203

38. Visual Studio Plug-insPlug-in by Tangible Engineeringhttp://bit.ly/dfFhEiT4 Editor by Clariushttp://bit.ly/cHfGRnResources

39. Resources will be postedBlog: http://www.codekindler.comEmail: joubin.najmaie@gmail.comResources

40. T4 / Code GenerationQ&A