Introduction to frameworks
- 2. Objective I want to be a software engineer
- 3. My first application • I don’t know any language • Well let’s choose a language for application programming and start learning.
- 4. … after 2 month • I have learned programming .. I am good at it and I can build any thing ….
- 5. My first application • As I can build anything I want to build a chess… I am a very good chess player. • I know all the rules and I know how to program ... What else do I need…
- 6. Week 1
- 7. Week 2
- 8. Week 3
- 9. My first application • After three weeks 600 lines of code. • Ok it’s easy. • After a month it’s 3500 lines of code in one file. Certainly I find scroll bar is very useful.
- 10. My first application • But when a bug occurs … lets debug it. • Now it seems building application is not as fun as it ought to be. • Now after learning a good lesson … well try something different.
- 11. My first application • Writing in one file creating problems .. :-? 3686
- 12. My first application Ok I will write small codes in different files…
- 13. My first application OMG now I have 100 files and to change some thing I have to change 10 files … it is worst than I imagined.
- 14. My first application I think I have found the problem .. This application may be very big and I alone can’t complete it. Let’s ask a friend.
- 15. My first application • Arrrrghhhh…. • Well we code differently so many misunderstanding… it complicates things more
- 16. My first application • Let’s stop trying and toiling • Think, how people writes a code which has millions of lines and thousands of developers • How ????? • …
- 17. My first application • Let’s see what can be done… • There is something wrong . What is the problem ?
- 18. Solutions • Separability • Independence • Readablity
- 19. My first application • Ok I successfully build a chess game • Now I want to build checker or other board games.
- 20. My Next Applications • I am so lazy, but I have to handle some things again that I have handled in chess game before. Like, – Point Table – Player Switching – Board status – Pieces – Save, load, undo, redo etc….
- 21. DRY • If I implement them again it will be wastage of time. • Don't Repeat Yourself (DRY) • Reduce repetition of code of all kinds
- 22. DRY • I want to reuse code that I used before in chess game
- 23. DRY • The functions need to customize as it was written in chess game i have to change it so that it also work for checker.
- 24. DRY • Some times this changes are different because there are so many options and varieties of board games
- 25. DRY • If I write those functionalities in a sort of generalized way such that it can be used in all board games. • Then I can develop this games very fast without repeating myself.
- 26. DRY • Now I can separate the similar codes that I can reuse for these board games. • If I need to build checker then I need similar structure as chess game.
- 27. DRY • If there is a structure that has similar features for these games then I do not need to start from the beginning. • I can straight jump into game logic. logic
- 28. Frameworks • The structure that I built to use for all board games can be called framework. • A reusable set of libraries or classes for a software system. • Used to implement the standard structure of an application.
- 29. Few Frameworks • For web application – Symfony – Zend – CodeIgniter – CakePHP – .NET – Django • For desktop application – Qt C++ – WxWidget
- 30. • Here is an idea. I am a human why should I repeat another humans work. • I haven't coded yet but I need not to because some one has already coded it for others to reuse. • There is no point to reinvent the wheel
- 31. MVC
- 32. Model • "Represent knowledge" • The data/business functionality
- 33. View • Visual representation of the model • The screens and widgets of app • Gets data from model & updates model
- 34. Controller • Link between user and system • Responsible for intercepting user input • Passes user input to view via messages
- 35. Questions?