Dependency Injection with PHP

Transcript

1. Dependency Injection with PHP @BastianHofmann

2. None
3. None

4. ?

5. None
6. None
7. None
8. None
9. None
10. None
11. None

12. Dependency Inversion

13. http://www.doolwind.com/blog/solid-principles-for-game-developers/

14. http://www.doolwind.com/blog/solid-principles-for-game-developers/

15. High-level modules should not depend on low level modules but

    on abstractions. ”

16. A B C

17. A B C <<interface>> <<interface>>

18. A B C <<interface>>

19. A B Adapter <<interface>> C

20. Dependencies

21. None

22. Dependency Injection

23. Constructor

24. None
25. None

26. Setter

27. None

28. Method argument

29. None

30. Constructing classes

31. None

32. Benefits

33. Easier to change

34. Easier testing

35. Only test the class, not the dependencies

36. None

37. Mocking

38. None
39. None

40. http://www.doolwind.com/blog/solid-principles-for-game-developers/

41. But...

42. None

43. Make it easier with factories

44. None

45. Dependency Injection Container

46. None

47. rg\injektor inspired by google-guice

48. https://github.com/researchgate/injektor

49. http://getcomposer.org/ http://packagist.org/

50. $ cat composer.json

51. $ wget http://getcomposer.org/composer.phar $ php composer.phar install Installing dependencies -

    Installing monolog/monolog (1.1.0) Downloading: 100% ... monolog/monolog suggests installing mlehner/ gelf-php (Allow sending log messages to a GrayLog2 server) Writing lock file Generating autoload files

52. Creating an instance of a class

53. None
54. None
55. None

56. Automatic creation of dependencies through Typehints

57. None

58. @inject

59. None

60. What classes can be injected?

61. No constructor

62. None

63. Constructor without arguments

64. None

65. Constructor with arguments that have default values

66. None

67. Injectable constructor

68. None
69. None

70. By the way: Property Injection

71. None

72. Singletons with public static getInstance method following the same rules

73. None

74. STOP: Don‘t use Singeltons

75. Singletons are evil!

76. Let the DIC take care of instances

77. @singleton

78. None

79. Passing additional, fixed values to instance

80. None

81. Working with Interfaces

82. None

83. But we can not create an instance of an Interface!

84. @implementedBy

85. None

86. Named @implementedBy

87. None
88. None

89. Method invocation at DIC

90. None

91. Same rules

92. None
93. None

94. And if you don‘t like annotations... ... or want to

    integrate 3rd party code
95. None
96. None
97. None
98. None

99. DEMO

100. None

101. https://github.com/symfony/DependencyInjection

102. None
103. None
104. None

105. https://github.com/bashofmann/dic_demo/

106. DEMO

107. None

108. https://github.com/zendframework/zf2

109. None
110. None

111. Automatic creation of dependencies through Typehints

112. DEMO

113. AOP

114. http://flow3.typo3.org/documentation/guide/partiii/ aspectorientedprogramming.html

115. class  Forum  {    /**      *  @FLOW3\Inject  

        *  @var  ApplicationLoggerInterface      */    protected  $applicationLogger;    /**      *  @param  Post  $post      *  @return  void      */    public  function  deletePost(Post  $post)  {        $this-­‐>applicationLogger-­‐>log('Removing  post');        $this-­‐>posts-­‐>remove($post);    } }

116. class  Forum  {    /**      *  Delete  a

      forum  post      *      *  @param  Post  $post      *  @return  void      */    public  function  deletePost(Post  $post)  {        $this-­‐>posts-­‐>remove($post);    } }

117. /**  *  @FLOW3\Aspect  */ class  LoggingAspect  {    /**  

        *  @FLOW3\Inject      *  @var  ApplicationLoggerInterface      */    protected  $applicationLogger;    /**      *  @FLOW3\Before("method(Forum-­‐>deletePost())")      */    public  function  logDeletePost(\TYPO3\FLOW3\AOP \JoinPointInterface  $joinPoint)  {        $post  =  $joinPoint-­‐>getMethodArgument('post');        $this-­‐>applicationLogger-­‐>log('Removing  post);    } }

118. rg\injektor inspired by google-guice

119. None

120. h"p://twi"er.com/Bas2anHofmann h"p://profiles.google.com/bashofmann h"p://lanyrd.com/people/Bas2anHofmann h"p://speakerdeck.com/u/bas2anhofmann h"ps://github.com/bashofmann [email protected] Did you like this

     talk? http://bit.ly/oscon2012_di_php