My presentation at Joomla and Beyond 2010 Conference about popular mistakes made by Joomla extension developers.

2. Why you can believe me 4 years of experience

3. Agenda Development Design MVC Other important questions Code optimization The most popular mistakes!

4. Joomla Components development

5. Model-View-Controller

6. How many times did you see this? Model View Controller User updates manipulates sees uses

7. An application is split by 3 departments which collaborate with each other to bring you the best results, but they don’t “disturb each other” at the same time!

9. MVC Controller

10. The controller is the boss!

11. You should use a controller for Getting request data; Getting model & view instances; Updating model states; Calling model action methods (e.g. delete, save, remove); Calling view methods to render a template.

12. You should not use a controller for Database task; Manipulating model data; Rendering templates. model & view tasks

13. A Controller in Joomla

14. JController

15. display() method revealed /libraries/joomla/application/component/controller.php Gets view instance Gets model instance Injects model into view Calls view’s display() method

16. Bad approaches for using controllers in Joomla

17. Good approaches for using controllers in Joomla

18. Bad approaches for using controllers in Joomla

19. Good approaches for using controllers in Joomla

20. MVC Model

21. A model is a hard worker!

22. You should use a model for Storing a state; Performing database tasks; Formatting data; All other data task.

23. You should not use a model for Getting request data; Rendering templates. controller & view tasks

24. A Model in Joomla

25. JModel The most unused model methods & properties. Why? $this->_db $this->_state $this->getDBO(); $this->setState($property, $value); $this->getState($property);

26. Bad approaches for using models in Joomla

27. Good approaches for using models in Joomla

28. Fat Model, Skinny Controller http://blog.astrumfutura.com/archives/373-The_M_in_MVC_Why_Models_are_Misunderstood_and_Unappreciated.html

29. MVC View

30. A view is a stylist!

31. You should use a view for Rendering templates; Rendering templates; Rendering templates.

32. You should not use a view for Database tasks; Database tasks; Database tasks. model tasks

33. A view in Joomla

34. JView lies between a model and a template View Data Template

35. You should use a Joomla view class for Getting data from models; Rearranging data (if needed); Assigning variables to templates; Rendering templates.

36. Don’t put everything you have into a view!

37. Keep your view methods small!

38. You shouldn’t use PHP in template files like this

39. You should use it like this

40. Don’t use variables in view templates other than the ones you assigned to

41. Keep your templates clear, assign all variables in view classes!

42. Add CSS and JS in the view template file … in this case they can be overwritten in a Joomla template

43. Joomla MVC revealed

44. Joomla MVC default task as it is Main component’s file request data calls Controller default task calls JController’s display() Model & view objects gets inserts Model into view calls JView’s display() gets Model data renders Template

45. The best way to figure out the Joomla framework is to dig into the code!

46. No, seriously Just dig into the code

47. After digging JController methods you can find out /libraries/joomla/application/component/controller.php How to insert other than the default model into your view class How to add another location for your model & view files How to set a default model state … and many more

48. Joomla MVC structures possible variants

52. Base controller approach

53. Base controller approach: main component file

54. Code Optimization

55. Code Optimization Write code Go! Write a bit more code Think over

56. A simple optimization Edit, publish, unpublish, save order, order up, order down, cancel, save, remove Base admin model Base admin controller Base admin view Helper classes Get ordering, save order, move, check out, check in, publish, remove The most used variables: option, document, view, controller, layout, etc. Everything that can be reused in templates

57. Code Documentation

58. Document your code http://www.phpdoc.org/ http://code.google.com/p/jsdoc-toolkit/ Every file, class, class property and method

60. Filter input, escape output! http://shiflett.org/blog/2005/feb/my-top-two-php-security-practices http://developer.joomla.org/security.html http://developer.joomla.org/security/articles-tutorials/258-preventing-sql-injections.html

61. Joomla Components design

62. We are developers, we don’t do design!

63. !!!!! We are developers, we don’t do design !!!!

64. Design principles for developers Set proper CSS classes & IDs, but leave design for template designers That’s all!

65. Thanks for coming! http://twitter.com/onesterov http://onesterov.com http://jookungfu.org http://mindk-lab.com [email_address]