CORS in Laravel 5

Based on https://github.com/asm89/stack-cors

For Laravel 4, please use the 0.2 branch!

About

The laravel-cors package allows you to send Cross-Origin Resource Sharing headers with ACL-style per-url configuration.

If you want to have have a global overview of CORS workflow, you can browse this image.

Features

• Handles CORS pre-flight OPTIONS requests
• Adds CORS headers to your responses

Configuration

The defaults are set in `config/cors.php'. Copy this file to your own config directory to modify the values. You can publish the config using this command:

php artisan vendor:publish --provider="Barryvdh\Cors\ServiceProvider"

Note: When using custom headers, like X-Auth-Token or X-Requested-With, you must set the allowedHeaders to include those headers. You can also set it to array('*') to allow all custom headers.

Note: If you are explicitly whitelisting headers, you must include Origin or requests will fail to be recognized as CORS.

return [
    'supportsCredentials' => false,
    'allowedOrigins' => ['*'],
    'allowedHeaders' => ['Content-Type', 'Accept'],
    'allowedMethods' => ['GET', 'POST', 'PUT',  'DELETE'],
    'exposedHeaders' => [],
    'maxAge' => 0,
    'hosts' => [],
]

allowedOrigins, allowedHeaders and allowedMethods can be set to array('*') to accept any value, the allowed methods however have to be explicitly listed.

Note: Because of http method overriding in Laravel, allowing POST methods will also enable the API users to perform PUT and DELETE requests as well.

Installation

Require the barryvdh/laravel-cors package in your composer.json and update your dependencies.

$ composer require barryvdh/laravel-cors

Add the Cors\ServiceProvider to your config/app.php providers array:

 'Barryvdh\Cors\ServiceProvider',

Usage

The ServiceProvider adds a route middleware you can use, called cors. You can apply this to a route or group to add CORS support.

Route::group(['middleware' => 'cors'], function(Router $router){
    $router->get('api', 'ApiController@index');
});

If you want CORS to apply for all your routes, add it as global middleware:

'Barryvdh\Cors\HandleCors',

Lumen

On Laravel Lumen, use LumenServiceProvider:

 'Barryvdh\Cors\LumenServiceProvider',

And load your configuration file manually:

$app->configure('cors');

Common problems and errors

When an error occurs, the middleware isn't run completely. So when this happens, you won't see the actual result, but will get a CORS error.

This could be a CSRF token error or just a simple problem.

Disabling CSRF protection for your API

In App\Http\Middleware\VerifyCsrfToken, add your routes to the exceptions:

protected $except = [
  'api/*'
];

Debugging errors

A simple but hacky method is to just always send the CORS headers. This isn't recommended for production, but it will show you the actual errors.

Add this to the top of public/index.php:

header("Access-Control-Allow-Origin: *");

Don't forget to remove that in production, so you can specify what routes/headers/origins are allowed.

You can add the CORS headers to the Errors also, in your Exception Handler:

public function render($request, Exception $e)
{
    $response = parent::render($request, $e);

    if ($request->is('api/*')) {
        app('Asm89\Stack\CorsService')->addActualRequestHeaders($response, $request);
    }

    return $response;
}

License

Released under the MIT License, see LICENSE.