Laravel (5.5.33) 加载过程（二）

本次说明代码

/*
|--------------------------------------------------------------------------
| 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';

---

主要实现的功能

　　1.实例化  Illuminate\Foundation\Application类

　　2.初始化基础路径

　　3.基本容器(app,Container)和对于类的绑定

　　4.基础服务的注册(事件服务EventServiceProvider  日志服务LogServiceProvider  路由服务RoutingServiceProvider)

　　5.别名的注册（vendor/laravel/framework/src/Illuminate/Foundation/Application.php文件中的 registerCoreContainerAliases 方法）

---

流程图

---

代码

<?php

/*
|--------------------------------------------------------------------------
| 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.
|
*/

/**
 * 对于其中的instance register singleton 方法到时候单独拎出来说明
 *
 * 1.设置基础路径
 * 2.使用instance 方法 绑定app 和Illuminate\Foundation\Application类的关系
 * 3.使用instance 方法 绑定Container 和Illuminate\Foundation\Application类的关系
 * 4.app变量中注册事件服务EventServiceProvider
 * 5.app变量中注册日志服务LogServiceProvider
 * 6.app变量中注册路由服务RoutingServiceProvider
 * 7.别名的注册（vendor/laravel/framework/src/Illuminate/Foundation/Application.php文件中的 registerCoreContainerAliases 方法）
 */
$app = new Illuminate\Foundation\Application(
    realpath(__DIR__.'/../')
);

/*
|--------------------------------------------------------------------------
| 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.
|
*/

/**
 * 把App\Http\Kernel::class 类下的参数 映射到lluminate\Contracts\Http\Kernel::class类中
 */
$app->singleton(
    Illuminate\Contracts\Http\Kernel::class,
    App\Http\Kernel::class
);

/**
 * 把App\Console\Kernel::class 类下的参数 映射到Illuminate\Contracts\Console\Kernel::class类中
 */
$app->singleton(
    Illuminate\Contracts\Console\Kernel::class,
    App\Console\Kernel::class
);

/**
 * 把App\Exceptions\Handler::class 类下的参数 映射到Illuminate\Contracts\Debug\ExceptionHandler::class类中
 */
$app->singleton(
    Illuminate\Contracts\Debug\ExceptionHandler::class,
    App\Exceptions\Handler::class
);

/*
|--------------------------------------------------------------------------
| 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;