Object Oriented Programming Ch3 SRP, DIP, ISP
- 1. Object Oriented Programming in Swift Ch 3 Single Responsibility Principle Dependency Inversion Principle Interface Segregation Principle Sai Li @ Yowoo Tech. 2016/1/9
- 2. References • Agile Software Development: Principles, Patterns, and Practice ( : ) by Robert C. Martin • Fundamental Object Oriented Programming by Hsuan-Tien Lin • by Teddy Chen • Essential Object-Oriented Programming by Josh Ko
- 4. Cohesion • Degree to which the elements of a module belong together • The force that cause a module or a class to change
- 5. Coupling • Degree of interdependence between software modules
- 7. Cohesion & Coupling Goal: high cohesion, low coupling
- 8. S.O.L.I.D • SRP: Single Responsibility Principle • OCP: Open Closed Principle • LSP: Liskov Substitution Principle • ISP: Interface Segregation Principle • DIP: Dependency Inversion Principle
- 9. Single Responsibility Principle “A class should have one, and only one, reason to change.”
- 10. SRP
- 11. SRP
- 12. Responsibility • A reason for change • More than one responsibility • coupled responsibilities • Fragile Design
- 13. Example
- 15. Persistence TDD
- 16. Single Responsibility Principle • One of the simplest and hardest principle • Software Design: The art of separating responsibility
- 17. S.O.L.I.D • SRP: Single Responsibility Principle • OCP: Open Closed Principle • LSP: Liskov Substitution Principle • ISP: Interface Segregation Principle • DIP: Dependency Inversion Principle
- 18. Dependency Inversion Principle 1. High-level modules should not depend on low- level modules. Both should depend on abstractions 2. Abstractions should not depend on details. Details should depend on abstractions.
- 19. Inversion of Control low level change -> high level change
- 20. Hollywood Principle: Don’t call me, I’ll call you Inversion of Control What they need
- 23. – Robert C. Martin “Depend on abstractions, not on concretions.”
- 24. - Design Pattern , GoF “Program to an interface, not an implementation.”
- 25. S.O.L.I.D • SRP: Single Responsibility Principle • OCP: Open Closed Principle • LSP: Liskov Substitution Principle • ISP: Interface Segregation Principle • DIP: Dependency Inversion Principle
- 28. Adaptor
- 29. Interface Segregation Principle “Client should NOT be forced to depend upon interfaces that they do not use”
- 30. Glass door Separate Clients == Separate Interfaces
- 33. “Fat” Interface • More than one responsibility • Coupled responsibilities • Fragile Design • Clients depend on what they need only
- 34. Recap • SRP: A class should have one, and only one, reason to change. • DIP: Depend on abstractions, not on concretions. • ISP: Make fine grained interfaces that are client specific
- 36. Liskov Substitution Principle Subtypes must be substitutable for their base types.
- 37. Rectangle & Square Problem
- 39. Segment Line Ray
- 40. Line: isOn(point: Intercept) == true LineSegment: isOn(point: Intercept) == ?
- 43. It’s the end of the beginning
- 44. – Sai Li “Live for interfaces, not implementations, except Lovers”
- 45. References • https://en.wikipedia.org/wiki/Cohesion_(computer_science) • https://drive.google.com/file/d/0ByOwmqah_nuGNHEtcU5OekdDMkk/view?pli=1 • http://teddy-chen-tw.blogspot.tw/2011/12/1.html • http://www.cs.utexas.edu/users/downing/papers/DIP.1996.pdf • http://howard-lyrics.blogspot.tw/2011/04/test.html • http://butunclebob.com/ArticleS.UncleBob.PrinciplesOfOod • https://upload.wikimedia.org/wikipedia/commons/thumb/f/f8/Laptop-hard-drive-exposed.jpg/220px-Laptop-hard-drive- exposed.jpg • http://sce2.umkc.edu/BIT/burrise/pl/design/cohesion-coupling-abstract.gif • http://freefeast.info/wp-content/uploads//2013/08/cohesion-vs.-coupling.jpg • http://cdn.mos.cms.futurecdn.net/7047e9b7bfca2b3b6f352495885e77c2.jpg • https://upload.wikimedia.org/wikipedia/commons/8/8d/DIPLayersPattern.png • http://flylib.com/books/4/444/1/html/2/images/11_3.jpg • http://flylib.com/books/4/444/1/html/2/images/11_4.jpg • http://stg-tud.github.io/sedc/Lecture/ws13-14/Images/DIP-RegulatorBase.png • http://stg-tud.github.io/sedc/Lecture/ws13-14/Images/DIP-RegulatorDIPCompliant.png • http://www.coolmath.com/sites/cmat/files/images/03-lines-01.gif • http://flylib.com/books/4/444/1/html/2/images/12_2.jpg • http://flylib.com/books/4/444/1/html/2/images/12_1.jpg