Laravel源码解析之路由的使用和示例详解

前言

我的解析文章并非深层次多领域的解析攻略。但是参考着开发文档看此类文章会让你在日常开发中更上一层楼。

废话不多说，我们开始本章的讲解。

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。 Illuminate/Routing/Router 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 Illuminate/Routing/Router 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 Illuminate/Routing/RouteCollection 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 = App/Api/Controllers/XxxController

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);}