Laravel 路由执行

摘要：路由执行代码展示控制器形式匿名函数形式控制器形式处理控制器参数解析返回过滤的从路径或主机名解析出来的对应的参数数组，类似方式调用控制器的方法可以有自己的区别于路由参数的

protected function runRouteWithinStack(Route $route, Request $request)
{
    $shouldSkipMiddleware = $this->container->bound("middleware.disable") &&
                            $this->container->make("middleware.disable") === true;

    $middleware = $shouldSkipMiddleware ? [] : $this->gatherRouteMiddleware($route);

    return (new Pipeline($this->container))
                    ->send($request)
                    ->through($middleware)
                    ->then(function ($request) use ($route) {
                        return $this->prepareResponse(
                            $request, $route->run()
                        );
                    });
}

public function run()
{
    $this->container = $this->container ?: new Container;

    try {
        // 控制器形式(Controller@Method)
        if ($this->isControllerAction()) {
            return $this->runController();
        }
        // 匿名函数形式
        return $this->runCallable();
    } catch (HttpResponseException $e) {
        return $e->getResponse();
    }
}

protected function runController()
{
    return (new ControllerDispatcher($this->container))->dispatch(
        $this, $this->getController(), $this->getControllerMethod()
    );
}
public function getController()
{
    $class = $this->parseControllerCallback()[0];

    if (! $this->controller) {
        $this->controller = $this->container->make($class);
    }

    return $this->controller;
}
protected function getControllerMethod()
{
    return $this->parseControllerCallback()[1];
}
protected function parseControllerCallback()
{
    return Str::parseCallback($this->action["uses"]);
}
public static function parseCallback($callback, $default = null)
{
    return static::contains($callback, "@") ? explode("@", $callback, 2) : [$callback, $default];
}
// IlluminateRoutingControllerDispatcher
public function __construct(Container $container)
{
    $this->container = $container;
}
public function dispatch(Route $route, $controller, $method)
{
    // 控制器参数解析
    $parameters = $this->resolveClassMethodDependencies(
        $route->parametersWithoutNulls(), $controller, $method
    );

    if (method_exists($controller, "callAction")) {
        return $controller->callAction($method, $parameters);
    }

    return $controller->{$method}(...array_values($parameters));
}
public function parametersWithoutNulls()
{
    // 返回过滤的从路径或主机名解析出来的对应的参数数组，类似 ["post"=>1,"comment"=>2]
    return array_filter($this->parameters(), function ($p) {
        return ! is_null($p);
    });
}
protected function resolveClassMethodDependencies(array $parameters, $instance, $method)
{
    // __invoke 方式调用
    if (! method_exists($instance, $method)) {
        return $parameters;
    }

    return $this->resolveMethodDependencies(
        $parameters, new ReflectionMethod($instance, $method)
    );
}
// 控制器的方法可以有自己的区别于路由参数的类类型参数，其他参数只能从路由获取
public function resolveMethodDependencies(array $parameters, ReflectionFunctionAbstract $reflector)
{
    $results = [];

    $instanceCount = 0;

    $values = array_values($parameters);
    
    foreach ($reflector->getParameters() as $key => $parameter) {
        // 类方法自己的类类型参数，尝试实例化
        $instance = $this->transformDependency(
            $parameter, $parameters
        );
        
        if (! is_null($instance)) {
            $instanceCount++;

            $results[] = $instance;
        } else {    // 按照类方法的参数顺序依次存放数据
            $results[] = isset($values[$key - $instanceCount])
                ? $values[$key - $instanceCount] : $parameter->getDefaultValue();
        }
    }

    return $results;
}
protected function transformDependency(ReflectionParameter $parameter, $parameters)
{
    $class = $parameter->getClass();
    // 类类型且没有实例化，则通过服务容器解决参数的依赖关系，并进行实例化
    if ($class && ! $this->alreadyInParameters($class->name, $parameters)) {
        return $this->container->make($class->name);
    }
}
protected function alreadyInParameters($class, array $parameters)
{
    return ! is_null(Arr::first($parameters, function ($value) use ($class) {
        return $value instanceof $class;
    }));
}
public function callAction($method, $parameters)
{
    return call_user_func_array([$this, $method], $parameters);
}

小结：
主要就是将路由获取到的参数依次对应到控制器方法的参数，当然控制器方法可以有自己的类类型参数

protected function runCallable()
{
    $callable = $this->action["uses"];
    // 一样的处理方式
    return $callable(...array_values($this->resolveMethodDependencies(
        $this->parametersWithoutNulls(), new ReflectionFunction($this->action["uses"])
    )));
}

即控制器的返回