Laravel 5.1 API Enable Cors

问题:

I've looked for some ways to enable cors on laravel 5.1 specifically, I have found some libs like:

https://github.com/neomerx/cors-illuminate

https://github.com/barryvdh/laravel-cors

but none of them has a implementation tutorial specifically to Laravel 5.1, I tried to config but It doesn't work.

If someone already implemented CORS on laravel 5.1 I would be grateful for the help...

回答1:

Here is my CORS middleware:

<?php namespace App\Http\Middleware;

use Closure;

class CORS {

    /**
     * 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: *");

        // ALLOW OPTIONS METHOD
        $headers = [
            'Access-Control-Allow-Methods'=> 'POST, GET, OPTIONS, PUT, DELETE',
            'Access-Control-Allow-Headers'=> 'Content-Type, X-Auth-Token, Origin'
        ];
        if($request->getMethod() == "OPTIONS") {
            // The client-side application can set only headers allowed in Access-Control-Allow-Headers
            return Response::make('OK', 200, $headers);
        }

        $response = $next($request);
        foreach($headers as $key => $value)
            $response->header($key, $value);
        return $response;
    }

}

To use CORS middleware you have to register it first in your app\Http\Kernel.php file like this:

protected $routeMiddleware = [
        //other middlewares
        'cors' => 'App\Http\Middleware\CORS',
    ];

Then you can use it in your routes

Route::get('example', array('middleware' => 'cors', 'uses' => 'ExampleController@dummy'));

回答2:

I always use an easy method. Just add below lines to \public\index.php file. You don't have to use a middleware I think.

header('Access-Control-Allow-Origin: *');  
header('Access-Control-Allow-Methods: GET, PUT, POST, DELETE, OPTIONS');

回答3:

I am using Laravel 5.4 and unfortunately although the accepted answer seems fine, for preflighted requests (like PUT and DELETE) which will be preceded by an OPTIONS request, specifying the middleware in the $routeMiddleware array (and using that in the routes definition file) will not work unless you define a route handler for OPTIONS as well. This is because without an OPTIONS route Laravel will internally respond to that method without the CORS headers.

So in short either define the middleware in the $middleware array which runs globally for all requests or if you're doing it in $middlewareGroups or $routeMiddleware then also define a route handler for OPTIONS. This can be done like this:

Route::match(['options', 'put'], '/route', function () {
    // This will work with the middleware shown in the accepted answer
})->middleware('cors');

I also wrote a middleware for the same purpose which looks similar but is larger in size as it tries to be more configurable and handles a bunch of conditions as well:

<?php

namespace App\Http\Middleware;

use Closure;

class Cors
{
    private static $allowedOriginsWhitelist = [
      'http://localhost:8000'
    ];

    // All the headers must be a string

    private static $allowedOrigin = '*';

    private static $allowedMethods = 'OPTIONS, GET, POST, PUT, PATCH, DELETE';

    private static $allowCredentials = 'true';

    private static $allowedHeaders = '';

    /**
     * Handle an incoming request.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  \Closure  $next
     * @return mixed
     */
    public function handle($request, Closure $next)
    {
      if (! $this->isCorsRequest($request))
      {
        return $next($request);
      }

      static::$allowedOrigin = $this->resolveAllowedOrigin($request);

      static::$allowedHeaders = $this->resolveAllowedHeaders($request);

      $headers = [
        'Access-Control-Allow-Origin'       => static::$allowedOrigin,
        'Access-Control-Allow-Methods'      => static::$allowedMethods,
        'Access-Control-Allow-Headers'      => static::$allowedHeaders,
        'Access-Control-Allow-Credentials'  => static::$allowCredentials,
      ];

      // For preflighted requests
      if ($request->getMethod() === 'OPTIONS')
      {
        return response('', 200)->withHeaders($headers);
      }

      $response = $next($request)->withHeaders($headers);

      return $response;
    }

    /**
     * Incoming request is a CORS request if the Origin
     * header is set and Origin !== Host
     *
     * @param  \Illuminate\Http\Request  $request
     */
    private function isCorsRequest($request)
    {
      $requestHasOrigin = $request->headers->has('Origin');

      if ($requestHasOrigin)
      {
        $origin = $request->headers->get('Origin');

        $host = $request->getSchemeAndHttpHost();

        if ($origin !== $host)
        {
          return true;
        }
      }

      return false;
    }

    /**
     * Dynamic resolution of allowed origin since we can't
     * pass multiple domains to the header. The appropriate
     * domain is set in the Access-Control-Allow-Origin header
     * only if it is present in the whitelist.
     *
     * @param  \Illuminate\Http\Request  $request
     */
    private function resolveAllowedOrigin($request)
    {
      $allowedOrigin = static::$allowedOrigin;

      // If origin is in our $allowedOriginsWhitelist
      // then we send that in Access-Control-Allow-Origin

      $origin = $request->headers->get('Origin');

      if (in_array($origin, static::$allowedOriginsWhitelist))
      {
        $allowedOrigin = $origin;
      }

      return $allowedOrigin;
    }

    /**
     * Take the incoming client request headers
     * and return. Will be used to pass in Access-Control-Allow-Headers
     *
     * @param  \Illuminate\Http\Request  $request
     */
    private function resolveAllowedHeaders($request)
    {
      $allowedHeaders = $request->headers->get('Access-Control-Request-Headers');

      return $allowedHeaders;
    }
}

Also written a blog post on this.

回答4:

barryvdh/laravel-cors works perfectly with Laravel 5.1 with just a few key points in enabling it.

1. After adding it as a composer dependency, make sure you have published the CORS config file and adjusted the CORS headers as you want them. Here is how mine look in app/config/cors.php

   <?php
   
   return [
   
       'supportsCredentials' => true,
       'allowedOrigins' => ['*'],
       'allowedHeaders' => ['*'],
       'allowedMethods' => ['GET', 'POST', 'PUT',  'DELETE'],
       'exposedHeaders' => ['DAV', 'content-length', 'Allow'],
       'maxAge' => 86400,
       'hosts' => [],
   ];
   

2. After this, there is one more step that's not mentioned in the documentation, you have to add the CORS handler 'Barryvdh\Cors\HandleCors' in the App kernel. I prefer to use it in the global middleware stack. Like this

   /**
    * The application's global HTTP middleware stack.
    *
    * @var array
    */
   protected $middleware = [
       'Illuminate\Foundation\Http\Middleware\CheckForMaintenanceMode',
       'Illuminate\Cookie\Middleware\EncryptCookies',
       'Illuminate\Cookie\Middleware\AddQueuedCookiesToResponse',
       'Illuminate\Session\Middleware\StartSession',
       'Illuminate\View\Middleware\ShareErrorsFromSession',
   
       'Barryvdh\Cors\HandleCors',
   
   ];
   

   But its up to you to use it as a route middleware and place on specific routes.

This should make the package work with L5.1