We combed before Laravel inversion of control and dependency injection In this article, we combine the Laravel framework to see how it is implemented.
1. Entry document
<?php /** * Laravel - A PHP Framework For Web Artisans * * @package Laravel * @author Taylor Otwell <taylor@laravel.com> */ define('LARAVEL_START', microtime(true));
1.1 register the autoloader, i.e. the auto loading mechanism of Laravel, as shown in Automatic loading mechanism of Laravel Composer
/* |-------------------------------------------------------------------------- | Register The Auto Loader |-------------------------------------------------------------------------- | | Composer provides a convenient, automatically generated class loader for | our application. We just need to utilize it! We'll simply require it | into the script here so that we don't have to worry about manual | loading any of our classes later on. It feels great to relax. | */ require __DIR__.'/../vendor/autoload.php';
1.2 turn on the light. Run the framework and make it ready so that it can load the application, run, and return the response.
/* |-------------------------------------------------------------------------- | Turn On The Lights |-------------------------------------------------------------------------- | | We need to illuminate PHP development, so let us turn on the lights. | This bootstraps the framework and gets it ready for use, then it | will load up this application so that we can run it and send | the responses back to the browser and delight our users. | */ $app = require_once __DIR__.'/../bootstrap/app.php';
In this step, the service container $app is instantiated.
1.3 running applications. Once we get the application, we can process the incoming request through the kernel kernel, and then return the relevant response results.
/* |-------------------------------------------------------------------------- | Run The Application |-------------------------------------------------------------------------- | | Once we have the application, we can handle the incoming request | through the kernel, and send the associated response back to | the client's browser allowing them to enjoy the creative | and wonderful application we have prepared for them. | */ $kernel = $app->make(Illuminate\Contracts\Http\Kernel::class); $response = $kernel->handle( $request = Illuminate\Http\Request::capture() ); $response->send(); $kernel->terminate($request, $response);
In this step, the kernel object is instantiated through the service container $app. The kernel processes the Request captured by the Request, and then sends the response result back. Finally, the requested kernel object stops working.
2. How to run
2.1 app/bootstrap/app.php file
2.1.1 create application: the first thing we need to do is to create a new application instance of Laravel, which will serve all parts of Laravel like glue, and it is also the IOC container of the system binding all kinds of parts.
/* |-------------------------------------------------------------------------- | Create The Application |-------------------------------------------------------------------------- | | The first thing we will do is create a new Laravel application instance | which serves as the "glue" for all the components of Laravel, and is | the IoC container for the system binding all of the various parts. | */ $app = new Illuminate\Foundation\Application( $_ENV['APP_BASE_PATH'] ?? dirname(__DIR__) );
2.1.1 let's see how the container is created
This construction method is under the vendor/laravel/framework/src/Illuminate/Foundation/Application.php directory. Its purpose is to create a new container
/** * Create a new Illuminate application instance. * * @param string|null $basePath * @return void */ public function __construct($basePath = null) { if ($basePath) { $this->setBasePath($basePath); } $this->registerBaseBindings(); $this->registerBaseServiceProviders(); $this->registerCoreContainerAliases(); }
2.1.1.1 set basic path
2.2.1.2 register basic binding to container
/** * Register the basic bindings into the container. * * @return void */ protected function registerBaseBindings() { static::setInstance($this); $this->instance('app', $this); $this->instance(Container::class, $this); $this->instance(PackageManifest::class, new PackageManifest( new Filesystem, $this->basePath(), $this->getCachedPackagesPath() )); }
The first step is to set the current object as a shared container example
Step 2 bind the 'app' abstract class to the current object
Step 3 bind the container abstract class to the current object
Step 4 bind the goods list to PackageManifest()
2.2.1.3 registered basic service provider
/** * Register all of the base service providers. * * @return void */ protected function registerBaseServiceProviders() { $this->register(new EventServiceProvider($this)); $this->register(new LogServiceProvider($this)); $this->register(new RoutingServiceProvider($this)); }
Register the three basic service providers: event, log and route to the current object
2.2.1.4 register core class alias to container
/** * Register the core class aliases in the container. * * @return void */ public function registerCoreContainerAliases() { foreach ([ 'app' => [\Illuminate\Foundation\Application::class, \Illuminate\Contracts\Container\Container::class, \Illuminate\Contracts\Foundation\Application::class, \Psr\Container\ContainerInterface::class], 'auth' => [\Illuminate\Auth\AuthManager::class, \Illuminate\Contracts\Auth\Factory::class], 'auth.driver' => [\Illuminate\Contracts\Auth\Guard::class], 'blade.compiler' => [\Illuminate\View\Compilers\BladeCompiler::class], 'cache' => [\Illuminate\Cache\CacheManager::class, \Illuminate\Contracts\Cache\Factory::class], 'cache.store' => [\Illuminate\Cache\Repository::class, \Illuminate\Contracts\Cache\Repository::class], 'config' => [\Illuminate\Config\Repository::class, \Illuminate\Contracts\Config\Repository::class], 'cookie' => [\Illuminate\Cookie\CookieJar::class, \Illuminate\Contracts\Cookie\Factory::class, \Illuminate\Contracts\Cookie\QueueingFactory::class], 'encrypter' => [\Illuminate\Encryption\Encrypter::class, \Illuminate\Contracts\Encryption\Encrypter::class], 'db' => [\Illuminate\Database\DatabaseManager::class], 'db.connection' => [\Illuminate\Database\Connection::class, \Illuminate\Database\ConnectionInterface::class], 'events' => [\Illuminate\Events\Dispatcher::class, \Illuminate\Contracts\Events\Dispatcher::class], 'files' => [\Illuminate\Filesystem\Filesystem::class], 'filesystem' => [\Illuminate\Filesystem\FilesystemManager::class, \Illuminate\Contracts\Filesystem\Factory::class], 'filesystem.disk' => [\Illuminate\Contracts\Filesystem\Filesystem::class], 'filesystem.cloud' => [\Illuminate\Contracts\Filesystem\Cloud::class], 'hash' => [\Illuminate\Hashing\HashManager::class], 'hash.driver' => [\Illuminate\Contracts\Hashing\Hasher::class], 'translator' => [\Illuminate\Translation\Translator::class, \Illuminate\Contracts\Translation\Translator::class], 'log' => [\Illuminate\Log\LogManager::class, \Psr\Log\LoggerInterface::class], 'mailer' => [\Illuminate\Mail\Mailer::class, \Illuminate\Contracts\Mail\Mailer::class, \Illuminate\Contracts\Mail\MailQueue::class], 'auth.password' => [\Illuminate\Auth\Passwords\PasswordBrokerManager::class, \Illuminate\Contracts\Auth\PasswordBrokerFactory::class], 'auth.password.broker' => [\Illuminate\Auth\Passwords\PasswordBroker::class, \Illuminate\Contracts\Auth\PasswordBroker::class], 'queue' => [\Illuminate\Queue\QueueManager::class, \Illuminate\Contracts\Queue\Factory::class, \Illuminate\Contracts\Queue\Monitor::class], 'queue.connection' => [\Illuminate\Contracts\Queue\Queue::class], 'queue.failer' => [\Illuminate\Queue\Failed\FailedJobProviderInterface::class], 'redirect' => [\Illuminate\Routing\Redirector::class], 'redis' => [\Illuminate\Redis\RedisManager::class, \Illuminate\Contracts\Redis\Factory::class], 'request' => [\Illuminate\Http\Request::class, \Symfony\Component\HttpFoundation\Request::class], 'router' => [\Illuminate\Routing\Router::class, \Illuminate\Contracts\Routing\Registrar::class, \Illuminate\Contracts\Routing\BindingRegistrar::class], 'session' => [\Illuminate\Session\SessionManager::class], 'session.store' => [\Illuminate\Session\Store::class, \Illuminate\Contracts\Session\Session::class], 'url' => [\Illuminate\Routing\UrlGenerator::class, \Illuminate\Contracts\Routing\UrlGenerator::class], 'validator' => [\Illuminate\Validation\Factory::class, \Illuminate\Contracts\Validation\Factory::class], 'view' => [\Illuminate\View\Factory::class, \Illuminate\Contracts\View\Factory::class], ] as $key => $aliases) { foreach ($aliases as $alias) { $this->alias($key, $alias); } } }
At this point, all kinds of basic paths, basic bindings, basic service providers, and core category names are registered or bound to the current application object, and the application instance of $app, that is, container example, is returned.
2.1.2 then bind the important interface to the application instance / container instance,
/* |-------------------------------------------------------------------------- | Bind Important Interfaces |-------------------------------------------------------------------------- | | Next, we need to bind some important interfaces into the container so | we will be able to resolve them when needed. The kernels serve the | incoming requests to this application from both the web and CLI. | */ $app->singleton( Illuminate\Contracts\Http\Kernel::class, App\Http\Kernel::class ); $app->singleton( Illuminate\Contracts\Console\Kernel::class, App\Console\Kernel::class ); $app->singleton( Illuminate\Contracts\Debug\ExceptionHandler::class, App\Exceptions\Handler::class );
2.1.3 then return to the application instance. This application instance will give the called script, so here we can separate the two steps of application instance construction and real application running and sending response.
/* |-------------------------------------------------------------------------- | Return The Application |-------------------------------------------------------------------------- | | This script returns the application instance. The instance is given to | the calling script so we can separate the building of the instances | from the actual running of the application and sending responses. | */ return $app;
At this point, the application instance construction is completed.
Back to the index.php entry file, we get the application instance / container example. Next, we run the application instance.
/* |-------------------------------------------------------------------------- | Run The Application |-------------------------------------------------------------------------- | | Once we have the application, we can handle the incoming request | through the kernel, and send the associated response back to | the client's browser allowing them to enjoy the creative | and wonderful application we have prepared for them. | */ $kernel = $app->make(Illuminate\Contracts\Http\Kernel::class); $response = $kernel->handle( $request = Illuminate\Http\Request::capture() ); $response->send(); $kernel->terminate($request, $response);