Laravel知识整理

为每个tag生成永久的唯一key vendor/laravel/framework/src/Illuminate/Cache/TagSet.php::resetTag
获取tags唯一的命名空间 vendor/laravel/framework/src/Illuminate/Cache/TagSet.php::getNamespace
生成tags唯一命名空间下的某key vendor/laravel/framework/src/Illuminate/Cache/TaggedCache.php::taggedItemKey

框架解读

实例自动注入

<?php
    //./vendor/laravel/framework/src/Illuminate/Container/Container.php
    public function build($concrete, array $parameters = [])
    {
        // If the concrete type is actually a Closure, we will just execute it and
        // hand back the results of the functions, which allows functions to be
        // used as resolvers for more fine-tuned resolution of these objects.
        //如果传入的$concrete是一个匿名函数，那么仅仅是执行并返回其结果
        if ($concrete instanceof Closure) {
            return $concrete($this, $parameters);
        }

        $reflector = new ReflectionClass($concrete);

        // If the type is not instantiable, the developer is attempting to resolve
        // an abstract type such as an Interface of Abstract Class and there is
        // no binding registered for the abstractions so we need to bail out.
        //判断$concreate是否可以被实例化，如果不可实例化抛出异常
        if (! $reflector->isInstantiable()) {
            $message = "Target [$concrete] is not instantiable.";

            throw new BindingResolutionContractException($message);
        }

        //将$concrete插入到build栈中
        $this->buildStack[] = $concrete;

        //获取$concrete的构造函数
        $constructor = $reflector->getConstructor();

        // If there are no constructors, that means there are no dependencies then
        // we can just resolve the instances of the objects right away, without
        // resolving any other types or dependencies out of these containers.
        //如果没有构造函数，从build栈中去除$concrete，然后直接new $concrete并返回实例
        if (is_null($constructor)) {
            array_pop($this->buildStack);

            return new $concrete;
        }

        //获取构造函数的形参信息
        $dependencies = $constructor->getParameters();

        // Once we have all the constructor's parameters we can create each of the
        // dependency instances and then use the reflection instances to make a
        // new instance of this class, injecting the created dependencies in.
        //如果传入了实参，那么将实参对照形参转化为key的形式
        $parameters = $this->keyParametersByArgument(
            $dependencies, $parameters
        );

        //获取构造函数各个依赖对应的实例
        $instances = $this->getDependencies(
            $dependencies, $parameters
        );

        //弹出build栈
        array_pop($this->buildStack);

        //根据参数实例构建并返回对象
        return $reflector->newInstanceArgs($instances);
    }

FAQ

1.同步提交表单时，需要使用csrf_token()添加token信息，那么ajax传输时怎么办呢

答: 简述(以laravel5.1为例):
在全局csrf中间件的handle方法中,会自动向请求的cookie中添加token(名为XSRF-TOKEN),客户端向服务端发送异步请求时header中带上这个token,服务端自动比对csrf信息

注意: axios默认自动支持CSRF保护。具体表现是在发送请求时检测cookie中是否存在XSRF-TOKEN，有的话就自动添加到header中

顺便说一下laravel全局csrf检测的实现
(1)Laravel开启session时生成一个token并存到session中

# vendor/laravel/framework/src/Illuminate/Session/Store.php:90

public function start()
{
    $this->loadSession();

    if (! $this->has('_token')) {
        $this->regenerateToken();
    }

    return $this->started = true;
}

(2)Laravel默认将注册csrf为全局中间件

# app/Http/Kernel.php

...
protected $middleware = [
    \App\Http\Middleware\VerifyCsrfToken::class,
];

(3)在csrf中间件执行方法handle中校验
先通过isReading判断请求方式，如果请求方式是READ|GET|OPTIONS其中一种，不做CSRF校验
再通过shouldPassThrouth判断当前请求uri在$excep属性数组中，如果不做校验
最后通过tokensMatch判断csrf token值是否与session中值相等，如果相等通过校验，不相等抛出异常
(请求中token获取顺序:_token > header中X-CSRF-TOKEN > header中X-XSRF-TOKEN)

# ...Http/Middleware/VerifyCsrfToken.php:47

public function handle($request, Closure $next)
{
    if ($this->isReading($request) || $this->shouldPassThrough($request) || $this->tokensMatch($request)) {
        return $this->addCookieToResponse($request, $next($request));
    }

    throw new TokenMismatchException;
}

//向响应中添加cookie信息
protected function addCookieToResponse($request, $response)
{
    $config = config('session');

    //向cookie中添加XSRF-TOKEN信息
    $response->headers->setCookie(
        new Cookie(
            'XSRF-TOKEN', $request->session()->token(), time() + 60 * 120,
            $config['path'], $config['domain'], $config['secure'], false
        )
    );

    return $response;
}
...

资料

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