Laravel框架下路由的使用（源碼解析）

本篇文章給大家帶來的內容是關於Laravel框架下路由的使用（源碼解析），有一定的參考價值，有需要的朋友可以參考一下，希望對你有所幫助。

前言

我的解析文章並非深層次多領域的解析攻略。但是參考着開發文檔看此類文章會讓你在日常開發中更上一層樓。

廢話不多說，我們開始本章的講解。

入口

Laravel啟動后，會先加載服務提供者、中間件等組件，在查找路由之前因為我們使用的是門面，所以先要查到Route的實體類。

注冊

第一步當然還是通過服務提供者，因為這是laravel啟動的關鍵，在 RouteServiceProvider 內加載路由文件。

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protected function mapApiRoutes() {     Route::prefix('api')          ->middleware('api')          ->namespace($this->namespace)  // 設置所處命名空間          ->group(base_path('routes/api.php'));  //所得路由文件絕對路徑 }

首先require是不可缺少的。因路由文件中沒有命名空間。 Illuminate\Routing\Router 下方法

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protected function loadRoutes($routes) {     if ($routes instanceof Closure) {         $routes($this);     } else {         $router = $this;           require $routes;     } }

隨后通過路由找到指定方法,依舊是 Illuminate\Routing\Router 內有你所使用的所有路由相關方法，例如get、post、put、patch等等，他們都調用了統一的方法 addRoute

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public function addRoute($methods, $uri, $action) {     return $this->routes->add($this->createRoute($methods, $uri, $action)); }

之后通過 Illuminate\Routing\RouteCollection addToCollections 方法添加到集合中

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protected function addToCollections($route) {     $domainAndUri = $route->getDomain().$route->uri();       foreach ($route->methods() as $method) {         $this->routes[$method][$domainAndUri] = $route;     }       $this->allRoutes[$method.$domainAndUri] = $route; }

添加后的結果如下圖所示

調用

通過 Illuminate\Routing\Router 方法開始運行路由實例化的邏輯

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protected function runRoute(Request $request, Route $route) {     $request->setRouteResolver(function () use ($route) {                   return $route;     });     $this->events->dispatch(new Events\RouteMatched($route, $request));       return $this->prepareResponse($request,         $this->runRouteWithinStack($route, $request)     ); } .... 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() // 此處調用run方法                         );                     }); }

在 Illuminate\Routing\Route 下 run 方用於執行控制器的方法

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public function run() {     $this->container = $this->container ?: new Container;       try {         if ($this->isControllerAction()) {             return $this->runController(); //運行一個路由並作出響應         }                       return $this->runCallable();     } catch (HttpResponseException $e) {         return $e->getResponse();     } }

從上述方法內可以看出 runController 是運行路由的關鍵,方法內運行了一個調度程序，將控制器 $this->getController() 和控制器方法 $this->getControllerMethod() 傳入到 dispatch 調度方法內

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protected function runController() {           return $this->controllerDispatcher()->dispatch(         $this, $this->getController(), $this->getControllerMethod()     ); }

這里注意 getController() 才是真正的將控制器實例化的方法

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public function getController() {           if (! $this->controller) {         $class = $this->parseControllerCallback()[0]; // 0=>控制器 xxController 1=>方法名 index         $this->controller = $this->container->make(ltrim($class, '\\')); // 交給容器進行反射     }       return $this->controller; }

鏈接：https://pan.baidu.com/s/1v5gm7n0L7TGyejCmQrMh2g 提取碼：x2p5

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實例化

依舊通過反射加載路由指定的控制器,這個時候build的參數$concrete = App\Api\Controllers\XxxController

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public function build($concrete) {     // If the concrete type is actually a Closure, we will just execute it and     // hand back the results of the functions, which allows functions to be     // used as resolvers for more fine-tuned resolution of these objects.     if ($concrete instanceof Closure) {         return $concrete($this, $this->getLastParameterOverride());     }           $reflector = new ReflectionClass($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.     if (! $reflector->isInstantiable()) {         return $this->notInstantiable($concrete);     }                     $this->buildStack[] = $concrete;       $constructor = $reflector->getConstructor();     // If there are no constructors, that means there are no dependencies then     // we can just resolve the instances of the objects right away, without     // resolving any other types or dependencies out of these containers.     if (is_null($constructor)) {                   array_pop($this->buildStack);                   return new $concrete;     }       $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.     $instances = $this->resolveDependencies(         $dependencies     );       array_pop($this->buildStack);           return $reflector->newInstanceArgs($instances); }

這時將返回控制器的實例，下面將通過url訪問指定方法，一般控制器都會繼承父類 Illuminate\Routing\Controller ,laravel為其設置了別名 BaseController

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public function dispatch(Route $route, $controller, $method) {           $parameters = $this->resolveClassMethodDependencies(         $route->parametersWithoutNulls(), $controller, $method     );       if (method_exists($controller, 'callAction')) {               return $controller->callAction($method, $parameters);     }               return $controller->{$method}(...array_values($parameters)); }

Laravel通過controller繼承的callAction去調用子類的指定方法，也就是我們希望調用的自定義方法。

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public function callAction($method, $parameters) {     return call_user_func_array([$this, $method], $parameters); }