Laravel生命周期启动(从创建应用实例到注册基础服务)过程解析

目录

• 引言
• bootstrap/app.php都做了什么
• 创建应用实例
• 注册基础绑定
• 注册基础服务
• 注册容器别名

/*
|--------------------------------------------------------------------------
| 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.
|我们要做的第一件事是创建一个新的Laravel应用程序实例，
|它作为Laravel所有组件的“粘合剂”,
|使系统绑定所有不同部分的IoC(控制反转)容器。
*/
$app = new Illuminate\Foundation\Application(
    $_ENV['APP_BASE_PATH'] ?? dirname(__DIR__)
);

public function __construct($basePath = null)
    {
        if ($basePath) {
            $this->setBasePath($basePath);
        }
        $this->registerBaseBindings();
        $this->registerBaseServiceProviders();
        $this->registerCoreContainerAliases();
    }

/**
         * Set the base path for the application.
         *
         * @param  string  $basePath
         * @return $this
         */
        public function setBasePath($basePath)
        {
            $this->basePath = rtrim($basePath, '\/');
            $this->bindPathsInContainer();
            return $this;
        }
    /**
     * Bind all of the application paths in the container.
     *
     * @return void
     */
    protected function bindPathsInContainer()
    {
        $this->instance('path', $this->path());
        $this->instance('path.base', $this->basePath());
        $this->instance('path.lang', $this->langPath());
        $this->instance('path.config', $this->configPath());
        $this->instance('path.public', $this->publicPath());
        $this->instance('path.storage', $this->storagePath());
        $this->instance('path.database', $this->databasePath());
        $this->instance('path.resources', $this->resourcePath());
        $this->instance('path.bootstrap', $this->bootstrapPath());
    }

public function instance($abstract, $instance)
{
    $this->removeAbstractAlias($abstract);
    $isBound = $this->bound($abstract);
    unset($this->aliases[$abstract]);
    // We'll check to determine if this type has been bound before, and if it has
    // we will fire the rebound callbacks registered with the container and it
    // can be updated with consuming classes that have gotten resolved here.
    $this->instances[$abstract] = $instance;
    if ($isBound) {
        $this->rebound($abstract);
    }
    return $instance;
}
/**
 * Remove an alias from the contextual binding alias cache.
 *
 * @param  string  $searched
 * @return void
 */
protected function removeAbstractAlias($searched)
{
    if (! isset($this->aliases[$searched])) {
        return;
    }
    foreach ($this->abstractAliases as $abstract => $aliases) {
        foreach ($aliases as $index => $alias) {
            if ($alias == $searched) {
                unset($this->abstractAliases[$abstract][$index]);
            }
        }
    }
}

$isBound = $this->bound($abstract);
    /**
     * Determine if the given abstract type has been bound.
     *
     * @param  string  $abstract
     * @return bool
     */
    public function bound($abstract)
    {
        return isset($this->bindings[$abstract]) ||
               isset($this->instances[$abstract]) ||
               $this->isAlias($abstract);
    }

//删除别名
unset($this->aliases[$abstract]);

$this->instances[$abstract] = $instance;

if ($isBound) {
            $this->rebound($abstract);
        }
    /**
     * Fire the "rebound" callbacks for the given abstract type.
     *
     * @param  string  $abstract
     * @return void
     */
    protected function rebound($abstract)
    {
        $instance = $this->make($abstract);
        foreach ($this->getReboundCallbacks($abstract) as $callback) {
            call_user_func($callback, $this, $instance);
        }
    }

$this->registerBaseBindings();

/**
 * Register the basic bindings into the container.
 *
 * @return void
 */
protected function registerBaseBindings()
{
    static::setInstance($this);
    //1，调用静态方法setInstance设置实例
    $this->instance('app', $this);
    //2，调用Instance ，将现有的实例注册为实例中的共享容器，查看Instance这个方法        (代码instance，上面已经说过)
    //注册app，Container
    $this->instance(Container::class, $this);
    //3,在容器中注册mix获取版本化的mix文件路径
    $this->singleton(Mix::class);
    $this->singleton(PackageManifest::class, function () {
        return new PackageManifest(
            new Filesystem, $this->basePath(), $this->getCachedPackagesPath()
        );
    });
}

$this->registerBaseServiceProviders();

/**
 * Register all of the base service providers.
 *
 * @return void
 */
protected function registerBaseServiceProviders()
{
    //注册事件服务
    $this->register(new EventServiceProvider($this));
    //注册日志
    $this->register(new LogServiceProvider($this));
    //注册路由
    $this->register(new RoutingServiceProvider($this));
}

$this->registerCoreContainerAliases();

//http内核
$app->singleton(
    Illuminate\Contracts\Http\Kernel::class,
    App\Http\Kernel::class
);
//console内核
$app->singleton(
    Illuminate\Contracts\Console\Kernel::class,
    App\Console\Kernel::class
);
//laravel的异常处理
$app->singleton(
    Illuminate\Contracts\Debug\ExceptionHandler::class,
    App\Exceptions\Handler::class
);