Dependency Injection with PHP

Transcript

1. Dependency Injection with PHP @BastianHofmann
4. ?
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
22. Dependency Injection
23. Constructor
26. Setter
28. Method argument
30. Constructing classes
32. Benefits
33. Easier to change
34. Easier testing
35. Only test the class, not the dependencies
37. Mocking
40. http://www.doolwind.com/blog/solid-principles-for-game-developers/
41. But...
43. Make it easier with factories
45. Dependency Injection Container
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
56. Automatic creation of dependencies through Typehints
58. @inject
60. What classes can be injected?
61. No constructor
63. Constructor without arguments
65. Constructor with arguments that have default values
67. Injectable constructor
70. By the way: Property Injection
72. Singletons with public static getInstance method following the same rules
74. STOP: Don‘t use Singeltons
75. Singletons are evil!
76. Let the DIC take care of instances
77. @singleton
79. Passing additional, fixed values to instance
81. Working with Interfaces
83. But we can not create an instance of an Interface!
84. @implementedBy
86. Named @implementedBy
89. Method invocation at DIC
91. Same rules
94. And if you don‘t like annotations... ... or want to integrate 3rd party code
99. DEMO
101. https://github.com/symfony/DependencyInjection
105. https://github.com/bashofmann/dic_demo/
106. DEMO
108. https://github.com/zendframework/zf2
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
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 mail@bas2anhofmann.de Did you like this talk? http://bit.ly/oscon2012_di_php