Laravel源码解析之路由的使用和示例详解

入口

Laravel启动后，会先加载服务提供者、中间件等组件，在查找路由之前因为我们使用的是门面，所以先要查到Route的实体类。

注册

第一步当然还是通过服务提供者，因为这是laravel启动的关键，在 RouteServiceProvider 内加载路由文件。

  protected function mapApiRoutes()  {    Route::prefix('api')       ->middleware('api')       ->namespace($this->namespace) // 设置所处命名空间       ->group(base_path('routes/api.php')); //所得路由文件绝对路径  }

首先require是不可缺少的。因路由文件中没有命名空间。 IlluminateRoutingRouter 下方法

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

随后通过路由找到指定方法,依旧是 IlluminateRoutingRouter 内有你所使用的所有路由相关方法，例如get、post、put、patch等等，他们都调用了统一的方法 addRoute

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

之后通过 IlluminateRoutingRouteCollection addToCollections 方法添加到集合中

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

添加后的结果如下图所示

实例化

依旧通过反射加载路由指定的控制器,这个时候build的参数$concrete = AppApiControllersXxxController

  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);  }

这时将返回控制器的实例，下面将通过url访问指定方法，一般控制器都会继承父类 IlluminateRoutingController ,laravel为其设置了别名 BaseController

  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通过controller继承的callAction去调用子类的指定方法，也就是我们希望调用的自定义方法。

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