How I learned to Stop Wiring and Love Autowiring Containers SymfonyCon Berlin 2016

Does managing YAML, XML or PHP container configurations make you sad? Do you dread making changes to your classes' dependencies for fear of the inevitable container configuration wiring blues? Life doesn't have to be this way! Not if your container supports autowiring, that is. Hear one developer's journey into the wild world of containers, learn how autowiring works, and find out how using autowiring can free you from having to manually configure every dependency.

Transcript

1. How I learned to Stop Wiring and Love Autowiring Containers joind.in/talk/666c9 Beau Simensen • beau.io • @beausimensen
2. Terminology
3. History
4. Implementations
5. Future
7. SOLID
8. D Dependency Injection?
9. D Dependency Inversion
10. Inversion of Control
11. Dependency Injection
12. Service Locator
13. Dependency Inversion .-- Dependency Injection | Inversion of Control --+ | `-- Service Locator
14. Dependency Inversion .-- Dependency Injection --. | | Inversion of Control --+--------------------------+-- Container | | `-- Service Locator -------' Dependency Injection Container Inversion of Control Container Service Container
15. Dependency Inversion .-- Dependency Injection --. | | Inversion of Control --+--------------------------+-- Container | | `-- Service Locator -------' Dependency Injection Container Inversion of Control Container Service Container Container
16. Dependency Inversion .-- Dependency Injection --. | | Inversion of Control --+--------------------------+-- Container | | `-- Service Locator -------' Dependency Injection Container ## . Inversion of Control Container ## ## ## == Service Container ## ## ## ## === Container /""""""""""""""""\___/ === ~~~ {~~ ~~~~ ~~~ ~~~~ ~~ ~ / ===- ~~~ \______ o __/ (no, not that other type of container) \ \ __/ \____\______/
17. Wiring
18. services: app.word_list: class: 'AppBundle\Game\WordList' calls: - [ 'addWord', [ 'computer' ] ] - [ 'addWord', [ 'monitors' ] ] - [ 'addWord', [ 'cellular' ] ] public: false app.game_context: class: 'AppBundle\Game\GameContext' arguments: ['@session'] public: false app.game_runner: class: 'AppBundle\Game\GameRunner' arguments: ['@app.game_context', '@?app.word_list']
20. Spring Frameworks' IoC Container
21. Beans
22. Explicit Wiring
23. XML > Annotations
24. <?xml version="1.0" encoding="UTF-8"?> <beans> <bean id="message" class="org.springbyexample.di.app.Message"> <property name="message" value="Spring is fun." /> </bean> </beans>
25. Google's Guice a lightweight dependency injection framework
26. public class RealBillingService implements BillingService { private final CreditCardProcessor processor; private final TransactionLog transactionLog; @Inject public RealBillingService(CreditCardProcessor processor, TransactionLog transactionLog) { this.processor = processor; this.transactionLog = transactionLog; } } Injector injector = Guice.createInjector(new BillingModule()); BillingService billingService = injector.getInstance( BillingService.class );
27. What if you need multiple instance with different dependencies? — Skeptical Beau
28. That never happens but if it does there are ways. — Beau's entirely unconvincing friend
29. Sorry R. (for the record, I should have listened to him...)
30. Bring this back to PHP! where $this = IoC/DI
31. •
32. Substrate IoC/DI Container for PHP
33. Stones .. instead of Beans
34. Explicit Wiring PHP Configuration
35. $context->add('configuration', array( 'className' => 'dd_configuration_PropertiesConfiguration', 'constructorArgs' => array( 'locations' => array( 'lithe_base.properties', 'app.properties', 'app.site.properties', ), ), )); $context->add('placeholderConfigurer', array( 'className' => 'substrate_DdConfigurationPlaceholderConfigurer', 'constructorArgs' => array( 'configuration' => $context->ref('configuration'), ), )); $context->add('logFactory', array( 'className' => 'dd_logging_LogFactory', ));
36. Autowiring
37. foreach ($constructor->getParameters() as $reflectionParamter) { $constructorArgumentName = $reflectionParamter->getName(); $paramClass = $reflectionParamter->getClass(); if ($paramClass) { $paramClassName = $paramClass->getName(); foreach ($this->stoneInstances as $testStone) { if ($testStone instanceof $paramClassName) { $constructorArgs[] = $testStone; break; } } } }
38. class dd_logging_FileLogger { public function __construct($filename) { /* .. */ } } class dd_logging_LogFactory { public function __construct(dd_logging_FileLogger $logger) { /* .. */ } } $context->add('logger', array( 'className' => 'dd_logging_FileLogger', 'constructorArgs' => array( 'filename' => __DIR__.'/app.log', ), )); $context->add('logFactory', array( 'className' => 'dd_logging_LogFactory', ));
39. Symfony PHP port of Spring
40. Symfony DIC Dependency Injection Component
41. Flexible
42. Compiler Passes!
43. COMPILED
45. Symfony & Silex
46. Subtly Painful
47. k.php
48. class ImportantService { private $loggerFactory; public function __construct($loggerFactory) { $this->loggerFactory = $loggerFactory; } public function doImportantTask() { $this ->loggerFactory() ->getLogger() ->info('Did important task!'); } }
49. # k.php class ImportantService { /* ... */ } $fileLogger = new FileLoger(__DIR__.'/app.log'); $loggerFactory = new LoggerFactory($fileLogger); $importantService = new ImportantService($loggerFactory); $importantService->doImportantTask();
50. # services.yml services: fileLogger: class: 'FileLogger' arguments: ['%kernel.root_dir%/app.log'] loggerFactory: class: 'LoggerFactory' arguments: ['@fileLogger'] importantService: class: 'ImportantService' arguments: ['@loggerFactory'] $importantService = $container->get('importantService'); $importantService->doImportantTask();
51. <!-- app/config/services.xml --> <?xml version="1.0" encoding="UTF-8" ?> <container> <services> <service id="fileLogger" class="FileLogger"> <argument>%kernel.root_dir%/app.log</argument> </service> <service id="loggerFactory" class="LoggerFactory"> <argument type="service" id="fileLogger" /> </service> <service id="importantService" class="ImportantService"> <argument type="service" id="loggerFactory" /> </service> </services> </container> $importantService = $container->get('importantService'); $importantService->doImportantTask();
52. $container = new Pimple\Container(); $container['fileLogger'] = function () { return new FileLogger(__DIR__.'/app.log'); }; $container['loggerFactory'] = function ($c) { return new LoggerFactory($c['fileLogger']); }; $container['importantService'] = function ($c) { return new ImportantService($c['loggerFactory']); }; $importantService = $container['importantService']; $importantService->doImportantTask();
53. $container = new Illuminate\Container\Container(); $container->singleton('fileLogger', function ($c) { return new FileLogger(__DIR__.'/app.log'); }); $container->singleton('loggerFactory', function ($c) { return new LoggerFactory($c->make('loggerFactory')); }); $container->singleton('importantService', function ($c) { return new ImportantService($c->make('loggerFactory')); }); $importantService = $container->make('importantService'); $importantService->doImportantTask();
54. $container = new Illuminate\Container\Container(); $container->singleton(FileLogger::class, function ($c) { return new FileLogger(__DIR__.'/app.log'); }); $container->singleton(LoggerFactory::class, function ($c) { return new LoggerFactory($c->make(FileLogger::class)); }); $container->singleton(ImportantService::class, function ($c) { return new ImportantService($c->make(LoggerFactory::class)); }); $importantService = $container->make(ImportantService::class); $importantService->doImportantTask();
55. Using class names for services is brilliant
56. foreach ($constructor->getParameters() as $reflectionParamter) { $constructorArgumentName = $reflectionParamter->getName(); $paramClass = $reflectionParamter->getClass(); if ($paramClass) { $paramClassName = $paramClass->getName(); foreach ($this->stoneInstances as $testStone) { if ($testStone instanceof $paramClassName) { $constructorArgs[] = $testStone; break; } } } }
57. foreach ($constructor->getParameters() as $reflectionParamter) { $constructorArgumentName = $reflectionParamter->getName(); $paramClass = $reflectionParamter->getClass(); if ($paramClass) { $paramClassName = $paramClass->getName(); $found = false; foreach ($this->stoneInstances as $testStone) { if ($testStone instanceof $paramClassName) { $constructorArgs[] = $testStone; $found = true; break; } } if (! $found) { $constructorArgs[] = $this->make($paramClassName); } } }
58. $container = new Illuminate\Container\Container(); $container->singleton(FileLogger::class, function ($c) { return new FileLogger(__DIR__.'/app.log'); }); $container->singleton(LoggerFactory::class, function ($c) { return new LoggerFactory($c->make(FileLogger::class)); }); $container->singleton(ImportantService::class, function ($c) { return new ImportantService($c->make(LoggerFactory::class)); }); $importantService = $container->make(ImportantService::class); $importantService->doImportantTask();
59. $container = new Illuminate\Container\Container(); $container->singleton(FileLogger::class, function ($c) { return new FileLogger(__DIR__.'/app.log'); }); $container->singleton(LoggerFactory::class, function ($c) { return new LoggerFactory($c->make(FileLogger::class)); }); $importantService = $container->make(ImportantService::class); $importantService->doImportantTask();
60. $container = new Illuminate\Container\Container(); $container->singleton(FileLogger::class, function ($c) { return new FileLogger(__DIR__.'/app.log'); }); $importantService = $container->make(ImportantService::class); $importantService->doImportantTask();
61. Binding Primitives
62. $container = new Illuminate\Container\Container(); $container ->when(FileLogger::class) ->needs('$filename') ->give(__DIR__.'/app.log'); $importantService = $container->make(ImportantService::class); $importantService->doImportantTask();
63. Change
64. class ImportantService { private $loggerFactory; public function __construct($loggerFactory) { $this->loggerFactory = $loggerFactory; } public function doImportantTask() { $this ->loggerFactory() ->getLogger() ->info('Did important task!'); } }
65. class Connection { public function execute() { /* ... */ } }
66. class ImportantService { private $loggerFactory; private $connection; public function __construct($loggerFactory, $connection) { $this->loggerFactory = $loggerFactory; $this->connection = $connection; } public function doImportantTask() { $this->connection->execute(); $this ->loggerFactory() ->getLogger() ->info('Did important task!'); } }
67. # k.php class Connection { /* ... */ } class ImportantService { /* ... */ } $fileLogger = new FileLoger(__DIR__.'/app.log'); $loggerFactory = new LoggerFactory($fileLogger); $connection = new Connection(); $importantService = new ImportantService( $loggerFactory, $connection ); $importantService->doImportantTask();
68. # services.yml services: fileLogger: class: 'FileLogger' arguments: ['%kernel.root_dir%/app.log'] loggerFactory: class: 'LoggerFactory' arguments: ['@fileLogger'] importantService: class: 'ImportantService' arguments: ['@loggerFactory'] $importantService = $container->get('importantService'); $importantService->doImportantTask();
69. # services.yml services: fileLogger: class: 'FileLogger' arguments: ['%kernel.root_dir%/app.log'] loggerFactory: class: 'LoggerFactory' arguments: ['@fileLogger'] connection: class: 'Connection' importantService: class: 'ImportantService' arguments: ['@loggerFactory', '@connection'] $importantService = $container->get('importantService'); $importantService->doImportantTask();
70. <!-- app/config/services.xml --> <?xml version="1.0" encoding="UTF-8" ?> <container> <services> <service id="fileLogger" class="FileLogger"> <argument>%kernel.root_dir%/app.log</argument> </service> <service id="loggerFactory" class="LoggerFactory"> <argument type="service" id="fileLogger" /> </service> <service id="importantService" class="ImportantService"> <argument type="service" id="loggerFactory" /> </service> </services> </container> $importantService = $container->get('importantService'); $importantService->doImportantTask();
71. <!-- app/config/services.xml --> <?xml version="1.0" encoding="UTF-8" ?> <container> <services> <service id="fileLogger" class="FileLogger"> <argument>%kernel.root_dir%/app.log</argument> </service> <service id="loggerFactory" class="LoggerFactory"> <argument type="service" id="fileLogger" /> </service> <service id="connection" class="Connection" /> <service id="importantService" class="ImportantService"> <argument type="service" id="loggerFactory" /> <argument type="service" id="connection" /> </service> </services> </container> $importantService = $container->get('importantService'); $importantService->doImportantTask();
72. $container = new Pimple\Container(); $container['fileLogger'] = function () { return new FileLogger(__DIR__.'/app.log'); }; $container['loggerFactory'] = function ($c) { return new LoggerFactory($c['fileLogger']); }; $container['importantService'] = function ($c) { return new ImportantService($c['loggerFactory']); }; $importantService = $container['importantService']; $importantService->doImportantTask();
73. $container = new Pimple\Container(); $container['fileLogger'] = function () { return new FileLogger(__DIR__.'/app.log'); }; $container['loggerFactory'] = function ($c) { return new LoggerFactory($c['fileLogger']); }; $container['connection'] = function ($c) { return new Connection(); }; $container['importantService'] = function ($c) { return new ImportantService( $c['loggerFactory'], $c['connection'] ); }; $importantService = $container['importantService']; $importantService->doImportantTask();
74. $container = new Illuminate\Container\Container(); $container ->when(FileLogger::class) ->needs('$filename') ->give(__DIR__.'/app.log'); $importantService = $container->make(ImportantService::class); $importantService->doImportantTask();
75. $container = new Illuminate\Container\Container(); $container ->when(FileLogger::class) ->needs('$filename') ->give(__DIR__.'/app.log'); $importantService = $container->make(ImportantService::class); $importantService->doImportantTask(); Nothing But Win!
76. Wonderful Developer Experience
77. XML and YAML fatigue — Beau, That Podcast episode 32
78. It had major impact on design I didn't want to have to tackle configuration
79. No more service identifiers Unless you want to use them
80. Interface Binding
81. class LoggerFactory { public function __construct(FileLogger $fileLogger) { /* ... */ } } class FileLogger { public function info($message) { /* ... */ } }
82. class LoggerFactory { public function __construct(Logger $logger) { /* ... */ } } interface Logger { public function info($message); } class FileLogger implements Logger { public function info($message) { /* ... */ } }
83. $container = new Illuminate\Container\Container(); $container ->when(FileLogger::class) ->needs('$filename') ->give(__DIR__.'/app.log'); $importantService = $container->make(ImportantService::class); $importantService->doImportantTask();
84. $container = new Illuminate\Container\Container(); $container ->when(FileLogger::class) ->needs('$filename') ->give(__DIR__.'/app.log'); $container->bind(Logger::class, FileLogger::class); $importantService = $container->make(ImportantService::class); $importantService->doImportantTask();
85. $container = new Illuminate\Container\Container(); $container ->when(FileLogger::class) ->needs('$filename') ->give(__DIR__.'/app.log'); $container->bind(Logger::class, SylogLogger::class); $importantService = $container->make(ImportantService::class); $importantService->doImportantTask();
86. But what about multiple instances with different configurations? — Beau from like 10 years ago
87. Contextual Binding
88. class NullLogger implements Logger { public function info($message) { // noop } }
89. class UnimportantService { public function __construct(LoggerFactory $loggerFactory) { /* .. */ } }
90. # k.php class Connection { /* ... */ } class ImportantService { /* ... */ } class UnimportantService { /* ... */ } $fileLogger = new FileLoger(__DIR__.'/app.log'); $fileLoggerFactory = new LoggerFactory($fileLogger); $connection = new Connection(); $importantService = new ImportantService( $fileLoggerFactory, $connection ); $nullLogger = new NullLogger(); $nullLoggerFactory = new LoggerFactory($nullLogger) $unimportantService = new UnimportantService( $nullLoggerFactory );
91. $container = new Illuminate\Container\Container(); $container ->when(FileLogger::class) ->needs('$filename') ->give(__DIR__.'/app.log'); $container->bind(Logger::class, FileLogger::class); $importantService = $container->make(ImportantService::class); $unimportantService = $container->make(UnimportantService::class);
92. $container = new Illuminate\Container\Container(); $container ->when(FileLogger::class) ->needs('$filename') ->give(__DIR__.'/app.log'); $container->bind(Logger::class, FileLogger::class); $container ->when(UnimportantService::class) ->needs(LoggerFactory::class) ->give(function ($c) { $nullLogger = $c->make(NullLogger::class); return new LoggerFactory($nullLogger); }); $importantService = $container->make(ImportantService::class); $unimportantService = $container->make(UnimportantService::class);
94. Pros
95. Amazing Developer Experience
96. Great for heavy refactoring sessions
97. More code writing, less configuration wrangling
98. Magic
99. Cons
100. Performance
101. Difficult to optimize
102. Magic
103. Best of Both Worlds?
104. Symfony 2.8: Service Autowiring
105. # app/config/services.yml services: service1: class: AppBundle\Service\Service1 service2: class: AppBundle\Service\Service2 arguments: ['@service1']
106. # app/config/services.yml services: service2: class: AppBundle\Service\Service2 autowire: true
107. What's the point? — Entitled Beau
108. kutny/autowiring-bundle
109. services: service2: class: AppBundle\Service\Service2 autowire: true
110. services: service2: class: AppBundle\Service\Service2
111. Still have to define services and assign them a service identifier.
112. #20264 Optional class for class named services @hason
113. # before services: Vendor\Namespace\Class: class: Vendor\Namespace\Class autowire: true # after services: Vendor\Namespace\Class: autowire: true
114. Still have to define services.
115. dunglas/action-bundle Symfony controllers, redesigned.
116. Scans directories and dynamically generates services with class names as the ID
117. class Homepage { private $router; private $twig; public function __construct(RouterInterface $router, \Twig_Environment $twig) { $this->router = $router; $this->twig = $twig; } /** * @Route("/myaction", name="my_action") */ public function __invoke(Request $request) { if (!$request->isMethod('GET')) { return new RedirectResponse($this->router->generateUrl('my_action'), 301); } return new Response($this->twig->render('mytemplate.html.twig')); } }
118. Despite the name of the package... It is not just limited to actions!
119. YAY! Performance! Optimization!
120. ? Magic!
121. A lot of experimentation in Dependency Injection
122. Thanks! beau.io • @beausimensen thatpodcast.io • @thatpodcast @sensiolabs • @blackfireio joind.in/talk/666c9