Laravel 5.4 api 允许跨域访问

需求: SPA单页应用请求接口, 报错

XMLHttpRequest cannot load http://api.console.vms3.com/api/user. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:8080' is therefore not allowed access.

意思就是服务器响应不允许跨域访问.

那我们就需要让服务器支持跨域访问, 也就是在响应头部中添加

'Access-Control-Allow-Origin: *'

文本使用Laravel 5.4版本

第一步: 创建中间件

创建 `app/Http/Middleware/AccessControlAllowOrigin.php` middleware 把 'Access-Control-Allow-Origin: *' 写入头部.

app/Http/Middleware/AccessControlAllowOrigin.php

<?phpnamespace App\Http\Middleware;use Closure;
use Illuminate\Support\Facades\Auth;class AccessControlAllowOrigin
{/**** Handle an incoming request.** @param  \Illuminate\Http\Request  $request* @param  \Closure  $next* @return mixed*/public function handle($request, Closure $next){header('Access-Control-Allow-Origin: *');header("Access-Control-Allow-Credentials: true");header("Access-Control-Allow-Methods: *");header("Access-Control-Allow-Headers: Content-Type,Access-Token");header("Access-Control-Expose-Headers: *");return $next($request);}}

第二步: 注册路由

注册这个 middleware 到 kernel 中.
分别在 protected $middleware  数组中和 protected $routeMiddleware 数组中
添加我们刚才创建的那个文件class名, 使用 `cors` 这个别名.

第三步: 设置中间件保护接口

然后在设置它保护 api , 就是$middlewareGroups['api'] 的数组中添加它的别名, 本文中是 'cors'

app/Http/Kernel.php

<?phpnamespace App\Http;use Illuminate\Foundation\Http\Kernel as HttpKernel;class Kernel extends HttpKernel
{/*** The application's global HTTP middleware stack.** These middleware are run during every request to your application.** @var array*/protected $middleware = [\Illuminate\Foundation\Http\Middleware\CheckForMaintenanceMode::class,\Illuminate\Foundation\Http\Middleware\ValidatePostSize::class,\App\Http\Middleware\TrimStrings::class,\Illuminate\Foundation\Http\Middleware\ConvertEmptyStringsToNull::class,\App\Http\Middleware\AccessControlAllowOrigin::class,];/*** The application's route middleware groups.** @var array*/protected $middlewareGroups = ['web' => [\App\Http\Middleware\EncryptCookies::class,\Illuminate\Cookie\Middleware\AddQueuedCookiesToResponse::class,\Illuminate\Session\Middleware\StartSession::class,// \Illuminate\Session\Middleware\AuthenticateSession::class,\Illuminate\View\Middleware\ShareErrorsFromSession::class,\App\Http\Middleware\VerifyCsrfToken::class,\Illuminate\Routing\Middleware\SubstituteBindings::class,],'api' => ['throttle:60,1','bindings','cors'],];/*** The application's route middleware.** These middleware may be assigned to groups or used individually.** @var array*/protected $routeMiddleware = ['auth' => \Illuminate\Auth\Middleware\Authenticate::class,'auth.basic' => \Illuminate\Auth\Middleware\AuthenticateWithBasicAuth::class,'bindings' => \Illuminate\Routing\Middleware\SubstituteBindings::class,'can' => \Illuminate\Auth\Middleware\Authorize::class,'guest' => \App\Http\Middleware\RedirectIfAuthenticated::class,'throttle' => \Illuminate\Routing\Middleware\ThrottleRequests::class,'cors' => \App\Http\Middleware\AccessControlAllowOrigin::class,];
}