New England Code Camp 14 presentation on architecting applications that use ADO.NET Entity Framework with repositories, persistence ignorant classes and unit testing.

1. Getting Persistence Ignorant with Entity Framework Julie Lermanthedatafarm.com jlerman@thedatafarm.com Twitter @julielerman

2. Julie Lerman consultant/mentor Microsoft MVP, INETA Speaker,ASPInsider, MCP, VTdotNET Leader website theDataFarm.com blog & twitter theDataFarm.com/blog@julielerman book web site LearnEntityFramework.com 2nd Edition (EF4) is now available

3. Agenda Background info Restructure simple app Explore complex solution

4. “-ilities” Benefits: Extensibility Adaptability Testability Maintainability Quality  Why should You Care? Persistence Ignorance (PI) Future-Proofing your investment Slide courtesy of Stephen Bohlen

5. Persistence Dependence Inherits from System.Data.Objects.ObjectContext var context = new PublishingEntities(); var book= (from b in context select books where bookid=3) .First(); b.Status = “Sent to Printer”; context.SaveChanges(); Entity Framework method Persistence Ignorance varbookMgr = new BookManager(); var book=bookMgr.GetBook(3); book.Status=“Sent to Printer”; bookMgr.Update(book); *your* class *your* method

6. EF1 & Default EF4 Classes

7. Dependencies

8. ObjectContext Manages Entities POCO “Snapshot”4.0 POCO + Dynamic Runtime Proxy (4.0) EntityObject (3.5 & 4.0) ObjectContext Person Object State info State info Order Object State info Detail Object State info Detail Object State info Order Object State info Detail Object State info Detail Object

9. POCO Basics With or without code generation “Convention” will auto-map classes/entities

10. EF4 POCO Support All entity properties must be represented Hand Code Code Generation with T4 and T4 templates Snapshot ObjectContext does all of the work Lazy Loading Virtual navigation properties Dynamic Runtime Proxies Mark all entity (model) properties as virtual Proxy emulates EntityObject behavior

11. IObjectSet Abstraction IObjectSet Collection-like behavior Add, Attach, Delete, etc. ObjectSet Concrete class Implements IObjectSet Inherits ObjectQuery public class ObjectSet:ObjectQuery,IObjectSet

12. Classes PI/Repositories System.Data.Entity Fake ObjectSet Fake Context & Data A EDM & ObjectContext Fake Context & Data B Unit of Work Class Repositories Class Repositories Class Repositories Class Repositories UI Tests

13. Entity Framework 4 Supports POCO Separation of concerns Unit Testing Coming soon: Code First, currently in CTP4, not released

14. Resources msdn.com/data Learnentityframework.com Testability and Entity Framework 4.0,Scott Allen, http://msdn.microsoft.com/en-us/ff714955.aspx Agile Entity Framework 4 Repository: blog series http://thedatafarm.com/blog/data-access/agile-entity-framework-4-repository-part-1-model-and-poco-classes/

15. Julie Lerman consultant/mentor Microsoft MVP, INETA Speaker,ASPInsider, MCP, VTdotNET Leader website theDataFarm.com blog & twitter theDataFarm.com/blog@julielerman book web site LearnEntityFramework.com 2nd Edition (EF4) is now available

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