These slides are from my presentation at the January 2010 Chicago Architects Group meeting on Dependency Injection and Inversion of Control Containers

1. Dependency Injection And IOC Containers Tim Murphy Technical Specialist - PSC Group, LLC

2. The Pursuit of the Loosely Coupled System

4. Service Proxy

5. Logging Service

6. Etc..Service Proxy Logging Service Tightly coupled services!

8. Creates brittle systems

10. The End(or is it)

11. Better…. … but still a lot of work There are so many dependencies in this system, how do I manage them all?

12. Dependency InjectionWith a Factory Pattern Entity “I need to be created, including have all my services crated and given to me.” Object Factory “ I know how to build all of this stuff.” Create a Concrete instance Create an Entity for me Instance for application Application “I need an Entity, but I don’t know how to create it.”

13. I want to spend my day writing functional business code, NOT a bunch of plumbing code…

14. Dependency Injection Frameworks to the Rescue! Structure Map Ninject Windsor Microsoft Unity

16. Service Proxy

17. Logging Service

18. Etc..Application “I need a concrete instance of an Entity…” Provider “You tell me what type of object you want, I give you the object you need:” Container “You ask me for objects, I create them based on my registrations”

19. DEMO TIME!

20. Related Topics Microsoft Provider Model Microsoft Extensibility Framework (MEF)

21. Some helpful links… Martin Fowler martinfowler.com/articles/injection.html MSDN Article on Dependency Injection pattern http://tinyurl.com/bm8wm5 Dependancey Injection tutorial http://tinyurl.com/5fysrq

22. Some helpful links… DI/IOC Frameworks: Ninject.org StructureMap.Sourceforge.net www.castleproject.org/container/index.html Unity (tinyurl.com/cm9pe3)

23. http://geekswithblogs.net/tmurphytmurphy@psclistens.comTwitter: twmurph