04. ServiceProvider Boot 解析

[xiaohuilam]

随着前面 《02. Kernel Handle解析》 和 《03. ServiceProvider Register 解析》 的结束，我们接下来要分析的便是 启动服务提供者 这个步骤。

代码

laravel/vendor/laravel/framework/src/Illuminate/Foundation/Bootstrap/BootProviders.php

Lines 1 to 19 in d081c91

	<?php
	namespace Illuminate\Foundation\Bootstrap;
	use Illuminate\Contracts\Foundation\Application;
	class BootProviders
	{
	/**
	* Bootstrap the given application.
	*
	* @param \Illuminate\Contracts\Foundation\Application $app
	* @return void
	*/
	public function bootstrap(Application $app)
	{
	$app->boot();
	}
	}

同 ServiceProvider Register 一样的，在 BootProviders 中也是调用了 Illuminate\Foundation\Application::boot()

laravel/vendor/laravel/framework/src/Illuminate/Foundation/Application.php

Lines 759 to 782 in d081c91

	/**
	* Boot the application's service providers.
	*
	* @return void
	*/
	public function boot()
	{
	if ($this->booted) {
	return;
	}
	// Once the application has booted we will also fire some "booted" callbacks
	// for any listeners that need to do work after this initial booting gets
	// finished. This is useful when ordering the boot-up processes we run.
	$this->fireAppCallbacks($this->bootingCallbacks);
	array_walk($this->serviceProviders, function ($p) {
	$this->bootProvider($p);
	});
	$this->booted = true;
	$this->fireAppCallbacks($this->bootedCallbacks);
	}

首先判断是否 boot 过。

然后通过触发 $bootingCallbacks 钩子

laravel/vendor/laravel/framework/src/Illuminate/Foundation/Application.php

Lines 823 to 834 in d081c91

	/**
	* Call the booting callbacks for the application.
	*
	* @param array $callbacks
	* @return void
	*/
	protected function fireAppCallbacks(array $callbacks)
	{
	foreach ($callbacks as $callback) {
	call_user_func($callback, $this);
	}
	}

$bootingCallbacks 是来自 02. HTTP Kernel Handle解析 登记的闭包，主要是服务于声明了 $defer = true 的服务提供者。

然后依次遍历 $this->serviceProviders 执行 Illuminate\Foundation\Application::bootProvider()

laravel/vendor/laravel/framework/src/Illuminate/Foundation/Application.php

Lines 784 to 795 in d081c91

	/**
	* Boot the given service provider.
	*
	* @param \Illuminate\Support\ServiceProvider $provider
	* @return mixed
	*/
	protected function bootProvider(ServiceProvider $provider)
	{
	if (method_exists($provider, 'boot')) {
	return $this->call([$provider, 'boot']);
	}
	}

其实就是运行一遍 ServiceProvider 的 boot 方法

接着将 Illuminate\Foundation\Application::$boot 设置为 true

最后触发 bootedCallbacks 钩子