Laravel5.5解析-$app初始化及核心类绑定

背景：断点调试寻找对应文件，忽略次要步骤，仅描述核心动作，‘/’表示index.php所在目录

地址:index.php

$app = require_once __DIR__.'/../bootstrap/app.php';

$app初始化

/…/bootstrap/app.php

$app = new Illuminate\Foundation\Application(
    realpath(__DIR__.'/../')
);//$app初始化工作

$app初始化的类及构造函数

class Application extends Container implements ApplicationContract,HttpKernelInterface
{
	//继承Container类，Container类实现应用契约接口与请求接口
    public function __construct($basePath = null){
       if ($basePath) {//$basePath = '/../'
           $this->setBasePath($basePath);//路径绑定
       }

       $this->registerBaseBindings();//基础绑定

       $this->registerBaseServiceProviders();//注册基础服务提供者

       $this->registerCoreContainerAliases();//注册别名
    }
}

路径绑定

Application的setBasePath(’/…/’)方法调用Container的instance($abstract,$instance)方法赋值Contaienr类instances
instances: array:9 [▼
“path” => “\var\www\app”
“path.base” => “\var\www”
“path.lang” => “\var\www\resources\lang”
“path.config” => “\var\www\config”
“path.public” => “\var\www\public”
“path.storage” => “\var\www\storage”
“path.database” => “\var\www\database”
“path.resources” => “\var\www\resources”
“path.bootstrap” => “\var\www\bootstrap”
]

基础绑定

  向Container的instances中添加绑定
	  "app" => Application {#2}
	  "Illuminate\Container\Container" => Application {#2}
	  "Illuminate\Foundation\PackageManifest" => PackageManifest {#4 ▼
	        +files: Filesystem {#5}
	        +basePath: "\var\www"
	        +vendorPath: "\var\www\vendor"
	        +manifestPath: "\var\www\bootstrap\cache\packages.php"
	        +manifest: null
	    }

	app与Container指向当前实例
	PackageMainfest 为包管理实例，构造方法中files注册文件系统实例

注册基础服务提供者

	//class Application
    protected function registerBaseServiceProviders()
    {
        $this->register(new EventServiceProvider($this));

        $this->register(new LogServiceProvider($this));

        $this->register(new RoutingServiceProvider($this));
    }

Event、Log、Routing基础服务继承ServiceProvider，初始化的时候将app属性赋值Application实例

	//class ServiceProvider	
    public function __construct($app)
    {
        $this->app = $app;
    }

执行Application类register方法

	//Application
	public function register($provider, $options = [], $force = false)
	    {
	        if (is_string($provider)) {
	            $provider = $this->resolveProvider($provider);
	        }
	
	        if (method_exists($provider, 'register')) {
	            $provider->register();//赋值bindings
	        }
			//将服务提供者添加到serviceProviders属性队列
	        //将服务提供者类名添加到loaderProviders属性
	        $this->markAsRegistered($provider);
	        
	        return $provider;
	    }

为provider注册提供了两种方法；
一种是字符串类名直接实例，
一种是执行$$provider->register()方法注册，
当前执行第二种方法，
回看当前EventServiceProvider实例的register方法

    public function register()
    {
        $this->app->singleton('events', function ($app) {
            return (new Dispatcher($app))->setQueueResolver(function () use ($app) {
                return $app->make(QueueFactoryContract::class);
            });
        });
    }

调用Application实例的singleton方法

	//class Continer
    public function singleton($abstract, $concrete = null)
    {
        $this->bind($abstract, $concrete, true);
    }

调用bind方法，赋值bindings

	//class Container
    public function bind($abstract, $concrete = null, $shared = false)
    {
        if (is_null($concrete)) {
            $concrete = $abstract;
        }
        
        if (! $concrete instanceof Closure) {
            $concrete = $this->getClosure($abstract, $concrete);
        }

        $this->bindings[$abstract] = compact('concrete', 'shared');
		
    }

回到Application类register方法中并执行markAsRegistered($provider)

	//class Application
    protected function markAsRegistered($provider)
    {
        $this->serviceProviders[] = $provider;

        $this->loadedProviders[get_class($provider)] = true;
    }

LogServerProvider、RoutingServiceProvider与之类似
别名绑定

	//class Application
    public function registerCoreContainerAliases()
    {
        foreach ([
            'app'                  => [self::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\Contracts\Hashing\Hasher::class],
            'translator'           => [\Illuminate\Translation\Translator::class, \Illuminate\Contracts\Translation\Translator::class],
            'log'                  => [\Illuminate\Log\Writer::class, \Illuminate\Contracts\Logging\Log::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);
            }
        }
    }

为alias属性赋值

$app核心类绑定

/…/bootstrap/app.php

/**
 *核心类绑定
 */
$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
);

调用bind函数

	//class Container
    public function singleton($abstract, $concrete = null)
    {
        $this->bind($abstract, $concrete, true);
    }

对字符串类名进行默认回调函数绑定

	//class Container
	public function bind($abstract, $concrete = null, $shared = false)
    {
        // If the factory is not a Closure, it means it is just a class name which is
        // bound into this container to the abstract type and we will just wrap it
        // up inside its own Closure to give us more convenience when extending.
        if (! $concrete instanceof Closure) {
            $concrete = $this->getClosure($abstract, $concrete);
        }
        $this->bindings[$abstract] = compact('concrete', 'shared');
    }

getClosure返回默认回调函数

	//class Container
    protected function getClosure($abstract, $concrete)
    {
        return function ($container, $parameters = []) use ($abstract, $concrete) {
            if ($abstract == $concrete) {
                return $container->build($concrete);
            }

            return $container->make($concrete, $parameters);
        };
    }

最终：返回$app

/…/bootstrap/app.php

return $app;