IoC container - Laravel Live India

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 LaravelLive India 2017
2. Hi, my name is Hannes.
3. !
5. madewithlove.be !%&'(
6. IoC Container
7. I O C
8. International O C
9. International Olympic C
10. International Olympic Committee
11. International Olympic Committee
12. WHAT IS IOC? IoC == Inversion of Control
13. But first: Design patterns 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. } } 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 = $storage; } } WHAT IS IOC?
23. new Service(new FtpStorage(new Ftp($settings))); WHAT IS IOC?
24. Don’t create these instances yourself WHAT IS IOC?
25. Inversion of Control IoC container to the rescue WHAT IS IOC?
26. 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?
27. 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?
28. class FtpStorage implements Storage { public function __construct(Ftp $ftp) { $this->ftp = $ftp; } public function get($key) { // Get it and return it. } } WHAT IS IOC?
29. FtpStora implements <interface> Storage Service depends on depends on Ftp WHAT IS IOC?
30. FtpStora <interface> Storage CacheDecor Service LogDecora S3Storage implements depends on WHAT IS IOC?
31. Dependency inversion: Interface + implementation Dependency injection: Injecting `Storage` into `Service` Inversion of Control: The container builds your objects and calls them 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. IoC container is here to help you with Composition WHAT IS IOC?
34. illuminate/container league/container symfony/dependency-injection aura/di zendframework/zend-di … container-interop/container-interop psr/container (PSR-11) CONSTRUCTOR INJECTION
35. Automatic constructor injection
36. class SendInvoice { public function __construct(Mailer $mailer) { $this->mailer = $mailer; } public function listen(InvoiceGeneratedEvent $event) { … } } CONSTRUCTOR INJECTION
37. Constructor injection CONSTRUCTOR INJECTION
38. $app->make(SendInvoice::class); CONSTRUCTOR INJECTION
39. Reflection CONSTRUCTOR INJECTION
40. (new \ReflectionClass($class)) ->getConstructor() ->getParameters(); CONSTRUCTOR INJECTION
41. Recursively CONSTRUCTOR INJECTION
42. Helping the container
43. Service Providers REGISTRATION
44. class ServiceProvider { public function register() { … } public function boot(Dispatcher $events) } REGISTRATION
45. class ServiceProvider { public function register() {…} public function boot(Dispatcher $events) { … } } REGISTRATION
46. class ServiceProvider { protected $defer = true; public function register() {…} public function provides() { return [ Mailer::class, SwiftMailer::class, ]; } } REGISTRATION
47. Register bindings in the register method REGISTRATION
48. $this->app->bind( MailerContract::class, SwiftMailer::class ); REGISTRATION - BINDING
49. $this->app->bind(Mailer::class, function () { $mailer = new SwiftMailer(); return new LogDecorator($mailer); }); REGISTRATION - BINDING
50. $this->app->singleton(Mailer::class, function () { … }); REGISTRATION - BINDING
51. $this->app->alias( Mailer::class, 'mailer' ); REGISTRATION - BINDING
52. Bind a concretion for every interface 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. Contextual binding REGISTRATION - CONTEXTUAL BINDING
57. $this->app ->when(PhotosController::class) ->needs(FilesystemInterface::class) ->give('fs.photos'); REGISTRATION - CONTEXTUAL BINDING
58. No more DB::connection('db1')->table($table)->…; REGISTRATION - CONTEXTUAL BINDING
59. $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
60. Inflection REGISTRATION
61. Inflection (aka “container events”) REGISTRATION - CONTAINER EVENTS
62. $this->app->resolving( function (Foo $foo) {…} ); REGISTRATION - CONTAINER EVENTS
63. use App\Contracts\EnvironmentAware; $this->app->resolving( function (EnvironmentAware $object) { $object->setEnv( $this->app->environment() ); } ); REGISTRATION - CONTAINER EVENTS
64. interface EnvironmentAware { public function setEnv($env); } REGISTRATION - CONTAINER EVENTS
65. trait EnvironmentAware { public function setEnv($env) { $this->env = $env; } private function isEnv($envs): bool { return in_array($this->env, (array) $envs); } } REGISTRATION - CONTAINER EVENTS
66. public function boot() { $this->app->resolving(function (LoggerAwareInterface $loggingObject) { $logger = $this->app->make(PsrLoggerInterface::class); $loggingObject->setLogger($logger); }); } REGISTRATION - CONTAINER EVENTS
67. Method injection REGISTRATION - CONTAINER EVENTS
68. Also useful for: - Quickly injecting stuff REGISTRATION - CONTAINER EVENTS
69. interface CommandBusAware trait CommandBusAware interface EventDispatcherAware trait EventDispatcherAware REGISTRATION - CONTAINER EVENTS
70. Also useful for: - Quickly injecting stuff REGISTRATION - CONTAINER EVENTS
71. Also useful for: - Quickly injecting stuff - Injecting soft dependencies REGISTRATION - CONTAINER EVENTS
72. $this->app->resolving(function (Mailer $mailer) $mailer->setQueueResolver(function () { return $this->app->make(Queue::class); }); ); REGISTRATION - CONTAINER EVENTS
74. Also useful for: - Quickly injecting stuff - Injecting soft dependencies REGISTRATION - CONTAINER EVENTS
75. Also useful for: - Quickly injecting stuff - Injecting soft dependencies - Setting configurable values REGISTRATION - CONTAINER EVENTS
76. $this->app->resolving(function (Validator) { $fileTypes = $app['config']->get(…) $validator->setAllowedFileTypes($fileTypes) ); REGISTRATION - CONTAINER EVENTS
77. Using the container
78. Preferably only for - Factories - Event Dispatchers - Router - Command Bus CALLING THE CONTAINER
79. $this->app->make('fs'); $this->app->make('fs', […]); $this->app->bind( 'fs', function ($app, $args) {…} ); CALLING THE CONTAINER
80. $this->app->call(function (Mailer $mailer) {}); $this->app->call([$listener, 'handle']); $this->app->call('Listener::handle'); $this->app->call('Listener@handle'); CALLING THE CONTAINER
81. $func = $this->app->wrap('Listener@handle'); $func();
82. public function wrap($callback) { return function () { $this->call($callback); }; }
83. Bonus
84. Solving circular dependencies BONUS - CIRCULAR DEPENDENCIES
85. $mailer = new Mailer(QueueInterface $queue); $queue = new Queue(MailerInterface $mailer); BONUS - CIRCULAR DEPENDENCIES
86. $mailer = new Mailer(); $queue = new Queue(MailerInterface $mailer); $mailer->setQueueResolver(function () { return $this->app->make('queue'); }); BONUS CIRCULAR DEPENDENCIES
87. recap: Reflection Binding Calling code Bonus
88. @hannesvdvreken LaravelLive India 2017 Thank you!
89. @hannesvdvreken LaravelLive India 2017 Time for questions.
90. • http:/ /mwl.be REFERENCES