Dependency Injection with PHP

1. Dependency Injection with PHP @BastianHofmann
5. ?
6. Dependency Injection Dependency Injection Containers Dependency Inversion Dependencies
9. ResearchGate gives science back to the people who make it happen. We help researchers build reputation and accelerate scientific progress. On their terms. ‟
17. Questions? Ask!
18. http://speakerdeck.com/u/bastianhofmann
19. Dependency Inversion
20. http://www.doolwind.com/blog/solid-principles-for-game-developers/
21. http://qafoo.com/presentations.html
22. http://www.doolwind.com/blog/solid-principles-for-game-developers/
23. High-level modules should not depend on low level modules but on abstractions. ”
24. A B C
25. A B C <<interface>> <<interface>>
26. A B C <<interface>>
27. A B Adapter <<interface>> C
30. Dependency Injection
31. Constructor
34. Setter
36. Method argument
38. Constructing classes
40. Benefits
42. Easier to change
43. Easier testing
44. Only test the class, not the dependencies
46. Mocking
49. http://www.doolwind.com/blog/solid-principles-for-game-developers/
50. But...
52. Make it easier with factories
54. Dependency Injection Container
56. rg\injektor inspired by google-guice
57. https://github.com/researchgate/injektor
58. http://getcomposer.org/ http://packagist.org/
59. $ cat composer.json
60. $ 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
62. Creating an instance of a class
66. PHP 5.5
67. Automatic creation of dependencies through Typehints
69. @inject
71. What classes can be injected?
72. No constructor
74. Constructor without arguments
76. Constructor with arguments that have default values
78. Injectable constructor
81. By the way: Property Injection
83. Singletons with public static getInstance method following the same rules
85. STOP: Don‘t use Singeltons
86. Singletons are evil!
87. Let the DIC take care of instances
88. @singleton
90. Passing additional, fixed values to instance
92. Working with Interfaces
94. But we can not create an instance of an Interface!
95. @implementedBy
97. Named @implementedBy
100. Providers
101. @providedBy
104. Method invocation at DIC
106. Same rules
109. And if you don‘t like annotations... ... or want to integrate 3rd party code
112. Great! So, how does it work?
113. Development: Reflection
114. Production: Generated Factory Classes
117. https://github.com/bashofmann/dic_demo/
118. DEMO
120. https://github.com/symfony/DependencyInjection
124. https://github.com/bashofmann/dic_demo/
125. DEMO
127. https://github.com/zendframework/zf2
130. Automatic creation of dependencies through Typehints
131. https://github.com/bashofmann/dic_demo/
132. DEMO
133. AOP
134. http://flow3.typo3.org/documentation/guide/partiii/ aspectorientedprogramming.html
135. 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);    } }
136. class  Forum  {    /**      *  Delete  a  forum  post      *      *  @param  Post  $post      *  @return  void      */    public  function  deletePost(Post  $post)  {        $this-­‐>posts-­‐>remove($post);    } }
137. /**  *  @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');    } }
139. 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? https://joind.in/7346