IoC container - Laravel Groningen

Did you know your IoC container can do a whole lot more than just constructor injection? Besides that it is actually packed with features. Inflectors, resolving callbacks, aliasing, method invocation to name a few. In this talk you will learn how to leverage the power of a great container and service providers to write better, loosely coupled code. Well designed code put together by your IoC container will make your applications SOLID, modular, lean and decoupled from the framework!

Transcript

1. IOC container @hannesvdvreken Laravel Groningen
2. Hi, my name is Hannes.
3. !
4. madewithlove.be
5. IoC Container
6. I O C
7. International O C
8. International Olympic C
9. International Olympic Committee
10. International Olympic Committee
11. WHAT IS IOC? IoC == Inversion of Control
12. But first: Design patterns WHAT IS IOC?
13. class Service { public function calculate() { // Get stuff from FTP. // Do calculations. // Return result. } } WHAT IS IOC?
14. class Service { public function __construct(Ftp $ftp) { } public function calculate() { // Get stuff from FTP. // Do calculations. // Return result. } } WHAT IS IOC?
15. class Service { public function __construct(Ftp $ftp) { } public function calculate() { // Get stuff from FTP. // Add caching to prevent hitting FTP over and over again // Do calculations. // Return result. } } WHAT IS IOC?
16. class Service { public function __construct(Ftp $ftp) { } public function calculate() { // Get stuff from FTP. // Add caching to prevent hitting FTP over and over again // Log that FTP is accessed. // Do calculations. // Return result. } } WHAT IS IOC?
17. class Service { public function __construct(Ftp $ftp) { } public function calculate() { // Get stuff from FTP. // Add caching to prevent hitting FTP over and over again // Log that FTP is accessed. // Do calculations. // Return result. } } WHAT IS IOC?
18. class FtpStorage { public function __construct(Ftp $ftp) { $this->ftp = $ftp; } public function get($key) { // Get it. // Cache it. // Log it. // Return it. } } WHAT IS IOC?
19. class Service { public function __construct(FtpStorage $storage) {
 $this->storage = $storage; } } WHAT IS IOC?
20. interface Storage { public function get($key); } WHAT IS IOC?
21. class FtpStorage implements Storage { public function __construct(Ftp $ftp) { $this->ftp = $ftp; } public function get($key) { … } } WHAT IS IOC?
22. class Service { public function __construct(Storage $storage) {
 $this->storage = $storage; } } WHAT IS IOC?
23. class CacheDecorator implements Storage { public function __construct(Cache $cache, Storage $storage) {…} public function get($key) { return $this->cache->remember($key, 60, function () { return $this->storage->get($key); }); } } WHAT IS IOC?
24. class LogDecorator implements Storage { public function __construct(LoggerInterface $log, Storage $storage) {…} public function get($key) { $this->log->info('Retrieved value for '.$key); return $this->storage->get($key); } } WHAT IS IOC?
25. class FtpStorage implements Storage { public function __construct(Ftp $ftp) { $this->ftp = $ftp; } public function get($key) { // Get it and return it. } } WHAT IS IOC?
26. Dependency inversion: Interface + implementation Dependency injection: Injecting `Storage` into `Service` Inversion of Control: The container builds your objects and calls them WHAT IS IOC?
27. FtpStorage Service depends on depends on Ftp WHAT IS IOC?
28. FtpStorage implements <interface> Storage Service depends on depends on Ftp WHAT IS IOC?
29. FtpStorage <interface> Storage CacheDecorator Service LogDecorator S3Storage depends on WHAT IS IOC? implements
30. new Service(new FtpStorage(new Ftp($settings))); WHAT IS IOC?
31. Don’t create these instances yourself WHAT IS IOC?
32. $container->get(Service::class); 1) Make FtpStorage 2) Wrap it with LogDecorator 3) Wrap LogDecorator instance with CacheDecorator 4) New up Service with CacheDecorator instance. WHAT IS IOC?
33. Inversion of Control IoC container to the rescue WHAT IS IOC?
34. IoC container is here to help you with Composition WHAT IS IOC?
35. illuminate/container league/container symfony/dependency-injection aura/di zendframework/zend-di … container-interop/container-interop psr/container (PSR-11) CONSTRUCTOR INJECTION
36. Automatic constructor injection
37. class SendInvoice { public function __construct(Mailer $mailer) { $this->mailer = $mailer; } public function listen(InvoiceGeneratedEvent $event) { … } } CONSTRUCTOR INJECTION
38. Constructor injection CONSTRUCTOR INJECTION
39. $app->make(SendInvoice::class); CONSTRUCTOR INJECTION
40. Reflection CONSTRUCTOR INJECTION
41. (new \ReflectionClass($class)) ->getConstructor() ->getParameters(); CONSTRUCTOR INJECTION
42. Recursively CONSTRUCTOR INJECTION
43. Helping the container
44. Service Providers REGISTRATION
45. class ServiceProvider { public function register() { … } public function boot(Dispatcher $events) } REGISTRATION
46. class ServiceProvider { public function register() {…} public function boot(Dispatcher $events) { … } } REGISTRATION
47. class ServiceProvider { protected $defer = true; public function register() {…} public function provides() { return [ Mailer::class, SwiftMailer::class, ]; } } REGISTRATION
48. Register bindings in the register method REGISTRATION
49. $this->app->bind( MailerContract::class, SwiftMailer::class ); REGISTRATION - BINDING
50. $this->app->bind(Mailer::class, function () { $mailer = new SwiftMailer(); return new LogDecorator($mailer); }); REGISTRATION - BINDING
51. $this->app->singleton(Mailer::class, function () { … }); REGISTRATION - BINDING
52. $this->app->alias( Mailer::class, 'mailer' ); REGISTRATION - BINDING
53. Bind everything with its class name REGISTRATION - BINDING
54. Unless you bind multiple versions REGISTRATION - BINDING
55. $this->app->bind('fs.photos', function () {}); $this->app->bind('fs.files', function () {}); REGISTRATION - BINDING
56. Bind a concretion for every interface REGISTRATION - BINDING
57. REGISTRATION - BINDING $this->app->bind( LoggerInterface::class, Monolog::class );
58. Contextual binding REGISTRATION - CONTEXTUAL BINDING
59. $this->app ->when(PhotosController::class) ->needs(FilesystemInterface::class) ->give('fs.photos'); REGISTRATION - CONTEXTUAL BINDING
60. No more DB::connection('db1')->table($table)->…; REGISTRATION - CONTEXTUAL BINDING
61. $this->app->bind('db.1', function () { return $this->app['db'] ->connection('db1'); }); $this->app ->when(EventListener::class) ->needs(ConnectionInterface::class) ->give('db.1'); REGISTRATION - CONTEXTUAL BINDING
62. Inflection REGISTRATION
63. Inflection (aka “container events”) REGISTRATION - CONTAINER EVENTS
64. $this->app->resolving( function (Foo $foo) {…} ); REGISTRATION - CONTAINER EVENTS
65. use App\Contracts\EnvironmentAware; $this->app->resolving( function (EnvironmentAware $object) { $object->setEnv( $this->app->environment() ); } ); REGISTRATION - CONTAINER EVENTS
66. interface EnvironmentAware { public function setEnv($env); } REGISTRATION - CONTAINER EVENTS
67. trait EnvironmentAware { public function setEnv($env) { $this->env = $env; } private function isEnv($envs): bool { return in_array($this->env, (array) $envs); } } REGISTRATION - CONTAINER EVENTS
68. public function boot() { $this->app->resolving(function (LoggerAwareInterface $loggingObject) { $logger = $this->app->make(PsrLoggerInterface::class); $loggingObject->setLogger($logger); }); } REGISTRATION - CONTAINER EVENTS
69. Method injection REGISTRATION - CONTAINER EVENTS
70. Also useful for: - Quickly injecting stuff REGISTRATION - CONTAINER EVENTS
71. interface CommandBusAware trait CommandBusAware interface EventDispatcherAware trait EventDispatcherAware REGISTRATION - CONTAINER EVENTS
72. Also useful for: - Quickly injecting stuff REGISTRATION - CONTAINER EVENTS
73. Also useful for: - Quickly injecting stuff - Injecting soft dependencies REGISTRATION - CONTAINER EVENTS
74. $this->app->resolving(function (Mailer $mailer) { $mailer->setQueueResolver(function () { return $this->app->make(Queue::class); }); ); REGISTRATION - CONTAINER EVENTS
76. Also useful for: - Quickly injecting stuff - Injecting soft dependencies REGISTRATION - CONTAINER EVENTS
77. Also useful for: - Quickly injecting stuff - Injecting soft dependencies - Setting configurable values REGISTRATION - CONTAINER EVENTS
78. $this->app->resolving(function (Validator) { $fileTypes = $app['config']->get(…) $validator->setAllowedFileTypes($fileTypes); ); REGISTRATION - CONTAINER EVENTS
79. Using the container
80. Preferably only for - Factories - Event Dispatchers - Router - Command Bus CALLING THE CONTAINER
81. $this->app->make('fs'); $this->app->make('fs', […]); $this->app->bind( 'fs', function ($app, $args) {…} ); CALLING THE CONTAINER
82. $this->app->call(function (Mailer $mailer) {}); $this->app->call([$listener, 'handle']); $this->app->call('Listener::handle'); $this->app->call('Listener@handle'); CALLING THE CONTAINER
83. $func = $this->app->wrap('Listener@handle'); $func();
84. public function wrap($callback) { return function () { $this->call($callback); }; }
85. Bonus
86. Solving circular dependencies BONUS - CIRCULAR DEPENDENCIES
87. $mailer = new Mailer(QueueInterface $queue); $queue = new Queue(MailerInterface $mailer); BONUS - CIRCULAR DEPENDENCIES
88. $mailer = new Mailer(); $queue = new Queue(MailerInterface $mailer); $mailer->setQueueResolver(function () { return $this->app->make('queue'); }); BONUS CIRCULAR DEPENDENCIES
89. recap: Reflection Binding Calling code Bonus
90. @hannesvdvreken Thank you! Laravel Groningen
91. @hannesvdvreken Time for questions. Laravel Groningen
92. • http:/ /mwl.be REFERENCES