IoC container beyond constructor injection - PHP & Laravel Eindhoven

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!

Feedback here: http://www.meetup.com/Laravel-Eindhoven/events/231269730/

Transcript

1. IOC container beyond constructor injection @hannesvdvreken PHP Eindhoven
2. Hi, my name is Hannes.
3. !
4. madewithlove.be
7. IoC Container
8. WHAT IS IOC? class Service { public function __construct(Ftp $ftp) { } public function calculate() { // Get stuff from FTP. // Do calculations. // Return result. } }
9. WHAT IS IOC? 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. } }
10. WHAT IS IOC? 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. } }
11. WHAT IS IOC? 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. } }
12. WHAT IS IOC? \ class FtpStorage { public function __construct(Ftp $ftp) { $this->ftp = $ftp; } public function get($key) { // Get it. // Cache it. // Log it. } }
13. WHAT IS IOC? class Service { public function __construct(FtpStorage $storage) {
 $this->storage = $storage; } }
14. WHAT IS IOC? interface Storage { public function get($key); }
15. WHAT IS IOC? \ class FtpStorage implements Storage { public function __construct(Ftp $ftp) { $this->ftp = $ftp; } public function get($key) { … } }
16. WHAT IS IOC? class Service { public function __construct(Storage $storage) {
 $this->storage = $storage; } }
17. WHAT IS IOC? new Service(new FtpStorage(new Ftp($settings)))
18. WHAT IS IOC? Give away control: Inversion of Control IoC container to the rescue
19. WHAT IS IOC? \ class CacheDecorator implements Storage { public function __construct(Cache $cache, Storage $storage) {…} public function store($key, $value) { return $this->cache->remember($key, 60, function () { return $this->storage->get($key); }); } }
20. WHAT IS IOC? \ class LogDecorator implements Storage { public function __construct(LoggerInterface $log, Storage $sto {…} public function store($key, $value) { $this->log->info('Retrieved value for '.$key); return $this->storage->get($key); } }
21. WHAT IS IOC? \ class FtpStorage implements Storage { public function __construct(Ftp $ftp) { $this->ftp = $ftp; } public function get($key) { // Get it and return it. } }
22. WHAT IS IOC? FtpStorage implements <interface> Storage CacheDecorator Service depends on LogDecorator S3Storage
23. WHAT IS IOC? $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.
24. WHAT IS IOC? Dependency injection: Injecting `Storage` into `Service` Dependency inversion: Interface + implementation Inversion of Control: The container builds our objects trough composition
25. WHAT IS IOC? IoC container is here to help you with Composition
26. CONSTRUCTOR INJECTION illuminate/container league/container symfony/dependency-injection aura/di … container-interop/container-interop
27. Automatic constructor injection
28. class SendInvoice { public function __construct(Mailer $mailer) { $this->mailer = $mailer; } public function listen(InvoiceGeneratedEvent $event) { … } }
29. CONSTRUCTOR INJECTION Constructor injection
30. $app->make(SendInvoice::class);
31. CONSTRUCTOR INJECTION Reflection
32. (new \ReflectionClass($class)) ->getConstructor() ->getParameters();
33. CONSTRUCTOR INJECTION Recursively
34. Helping the container
35. REGISTRATION Service Providers
36. class ServiceProvider { public function register() { … } public function boot(Dispatcher $event }
37. class ServiceProvider { public function register() {…} public function boot(Dispatcher $event { … } }
38. class ServiceProvider { protected $defer = true; public function register() {…} public function provides() { return [ Mailer::class, SwiftMailer::class, ]; } }
39. REGISTRATION Register bindings in the register method
40. REGISTRATION - BINDING $this->app->bind( MailerContract::class, SwiftMailer::class );
41. REGISTRATION - BINDING $this->app->bind(Mailer::class, function ( $mailer = new SwiftMailer(); return new LogDecorator($mailer); });
42. REGISTRATION - BINDING $this->app->singleton(Mailer::class, funct … });
43. REGISTRATION - BINDING $this->app->alias( Mailer::class, 'mailer' );
44. REGISTRATION Bind a concretion for every interface
45. REGISTRATION Bind everything with its class name
46. REGISTRATION Unless you bind multiple versions
47. REGISTRATION $this->app->bind('fs.photos', function () $this->app->bind('fs.files', function () {
48. REGISTRATION - CONTEXTUAL BINDING Contextual binding
49. REGISTRATION - CONTEXTUAL BINDING $this->app ->when(PhotosController::class) ->needs(FilesystemInterface::class) ->give('fs.photos');
50. REGISTRATION - CONTEXTUAL BINDING No more DB::connection('db1')->table($table)->…;
51. $this->app->bind('db.1', function () { return $this->app['db'] ->connection('db1'); }); $this->app ->when(EventListener::class) ->needs(ConnectionInterface::class) ->give('db.1');
52. Inflection REGISTRATION - CONTAINER EVENTS
53. REGISTRATION - CONTAINER EVENTS Inflection (aka “container events”)
54. REGISTRATION - CONTAINER EVENTS $this->app->resolving( function (Foo $foo) {…} );
55. use App\Contracts\EnvironmentAware; $this->app->resolving( function (EnvironmentAware $object) { $object->setEnv( $this->app->environment() ); } );
56. interface EnvironmentAware { public function setEnv($env); }
57. trait EnvironmentAware { public function setEnv($env) { $this->env = $env; } private function isEnv($envs): bool { return in_array($this->env, (array) $envs); } }
58. REGISTRATION - CONTAINER EVENTS Method injection
59. REGISTRATION - CONTAINER EVENTS Also useful for: - Quickly injecting stuff
60. REGISTRATION - CONTAINER EVENTS interface CommandBusAware trait CommandBusAware interface EventDispatcherAware trait EventDispatcherAware
61. REGISTRATION - CONTAINER EVENTS Also useful for: - Quickly injecting stuff
62. REGISTRATION - CONTAINER EVENTS Also useful for: - Quickly injecting stuff - Injecting soft dependencies
63. $this->app->resolving(function (Mailer $ma { $mailer->setQueueResolver(function () { return $this->app->make(Queue::class }); );
65. REGISTRATION - CONTAINER EVENTS Also useful for: - Quickly injecting stuff - Injecting soft dependencies
66. REGISTRATION - CONTAINER EVENTS Also useful for: - Quickly injecting stuff - Injecting soft dependencies - Setting configurable values
67. $this->app->resolving(function (Validator) { $fileTypes = $app['config']->get(…) $validator->setAllowedFileTypes($fileT );
68. REGISTRATION - TAGGING Tagging
69. $this->app->tag('fs.files', 'fs'); $this->app->tag('fs.photos', 'fs');
70. $this->app->tag( ['fs.photos', 'fs.files'], 'fs' );
71. $this->app->tag( 'fs.photos', ['fs', 'photos'] );
72. $this->app->tagged('fs');
73. Using the container
74. CALLING THE CONTAINER Preferably only for - Factories - Event Dispatchers - Router - Command Bus
75. $this->app->make('fs'); $this->app->make('fs', […]); $this->app->bind( 'fs', function ($app, $args) {…} );
76. $this->app->call(function (Mailer $mailer) $this->app->call([$listener, 'handle']); $this->app->call('Listener::handle'); $this->app->call('Listener@handle');
77. $func = $this->app->wrap('Listener@handle' $func();
78. public function wrap($callback) { return function () { $this->call($callback); }; }
79. $this->app->tagged('fs');
80. Bonus
81. BONUS - SOFT DEPENDENCIES Solving circular dependencies
82. BONUS - CIRCULAR DEPENDENCIES Solving circular dependencies
83. BONUS - CIRCULAR DEPENDENCIES $mailer = new Mailer(QueueInterface $queue); $queue = new Queue(MailerInterface $mailer);
84. BONUS - CIRCULAR DEPENDENCIES $mailer = new Mailer(); $queue = new Queue(MailerInterface $mailer); $mailer->setQueueResolver(function () { return $this->app->make('queue'); });
85. BONUS - NOT SUPPORTED Not supported!
86. BONUS - NOT SUPPORTED Contextual binding for methods
87. BONUS - NOT SUPPORTED https:/ /github.com/laravel/ framework/pull/12183
88. BONUS - METHOD LEVEL CONTEXTUAL BINDING $this->app—>when('Foo@bar') ->needs(QueueContract::class) ->give('queue.redis');
89. BONUS - METHOD LEVEL CONTEXTUAL BINDING $this->app—>when('Foo@bar') takes precedence over $this->app—>when('Foo')
90. Reflection Binding Calling code Bonus
91. Thank you! https://joind.in/talk/xxxxx @hannesvdvreken PHP Eindhoven
92. Time for questions. @hannesvdvreken PHP Eindhoven
93. • http:/ /mwl.be REFERENCES