Dependency Inversion Principle
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This document discusses dependency inversion and dependency injection. It defines dependency inversion as high-level modules not depending on low-level modules, and both depending on abstractions instead of details depending on abstractions. The document outlines benefits like loose coupling, reusability, and testability. It also discusses providing dependencies through injection or a service locator and frameworks that support inversion of control like Autofac and NInject.
Dependency Inversion Principle
- 1. http://lifetuned.com http://pikpak.me Dependency Inversion @tommysqueak http://tomphilip.me
- 2. About • Dependency Injection • Service Location • TDD & Mocking - How they play together nicely • Auto-mocking • IOC - Tools, Features, Usage, Pros/Cons, Best Practice
- 4. Definition • High-level modules should not depend on low-level modules. Both should depend on abstractions. • Abstractions should not depend upon details. Details should depend upon abstractions.
- 5. Design Patterns Dependency Injection Service Locator
- 6. Story As a Customer I want to change my password In order to keep my account secure Scenario Given I’m an account holder When I change my password Then It should ensure it is a strong password And it should change my password And it should notify me it has been changed
- 7. Demo
- 8. Benefits • Loose coupling • Re-use • Testability
- 10. Provide Dependency Injection Service Locator
- 11. Usage • Registration • Entry Point
- 12. Demo
- 13. Frameworks •AutoFac • NInject • Castle Windsor • StructureMap • Unity
- 14. How They Look
- 15. A Little Best Practice • Internal code should not reference the container directly • Verify registration with tests • Constructor Injection over Setter Injection over Service Location
- 16. Picture Credits • http://www.flickr.com/ • http://www.flickr.com/ photos/smil/4196304056/ - photos/gcwest/ Patterns 281385801/ - containers • http://lostechies.com/ derickbailey/2009/02/11/ solid-development- principles-in-motivational- pictures/ - SOLID pictures • http://www.flickr.com/ photos/kevindean/ 4031083510/ - trolley