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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
调用
通过 Illuminate\Routing\Router 方法开始运行路由实例化的逻辑
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() // 此处调用 run 方法
);
});
}
在 Illuminate\Routing\Route 下 run 方用于执行控制器的方法
public function run()
{
$this->container = $this->container ?: new Container;
try {
if ($this->isControllerAction()) {
return $this->runController(); // 运行一个路由并作出响应
}
return $this->runCallable();
} catch (HttpResponseException $e) {
return $e->getResponse();
}
}
从上述方法内可以看出 runController 是运行路由的关键, 方法内运行了一个调度程序，将控制器 $this->getController() 和控制器方法 $this->getControllerMethod() 传入到 dispatch 调度方法内
protected function runController()
{
return $this->controllerDispatcher()->dispatch(
$this, $this->getController(), $this->getControllerMethod()
);
}
这里注意 getController() 才是真正的将控制器实例化的方法
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, ‘\\’)); // 交给容器进行反射
}
return $this->controller;
}
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);
}
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 Illuminate\Routing\Controller ,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);
}
致谢
感谢你看到这里，本篇文章源码解析靠个人理解。如有出入请拍砖。
希望本篇文章可以帮到你。谢谢
