nelmio/cors-bundle 2.4.0

The NelmioCorsBundle package essentially enables Cross-Origin Resource Sharing (CORS) headers support in your Symfony PHP application. This is key for allowing secure cross-domain data transfers, with an emphasis on building API-based infrastructure that's compatible with AJAX calls in web applications.

You can integrate and use the nelmio/cors-bundle in your Symfony application in the following way:

Firstly, install the package via Composer. If you're using Symfony Flex, you can run:

composer req cors

For non-Symfony Flex use, require the nelmio/cors-bundle in your composer.json and update your dependencies:

$ composer require nelmio/cors-bundle

Then, add the NelmioCorsBundle to your application's kernel:

public function registerBundles()
{
    $bundles = [
        // ...
        new Nelmio\CorsBundle\NelmioCorsBundle(),
        // ...
    ];
    // ...
}

Next, Symfony Flex generates a default configuration in config/packages/nelmio_cors.yaml. You can customize the CORS settings for paths and allowed headers and methods. An example configuration:

nelmio_cors:
    defaults:
        allow_origin: ['*']
        allow_headers: ['X-Custom-Auth']
        allow_methods: ['POST', 'PUT', 'GET', 'DELETE']
        max_age: 3600
    paths:
        '^/api/':
            allow_origin: ['*']
            allow_headers: ['X-Custom-Auth']
            allow_methods: ['POST', 'PUT', 'GET', 'DELETE']
            max_age: 3600

Here, CORS requests from any origin are allowed on /api/, with some methods defined as allowed. Preflight requests can be cached for 3600 seconds.

The documentation for the nelmio/cors-bundle lives in the README file on the GitHub repository (https://github.com/nelmio/NelmioCorsBundle), where you can find information about the package's features, installation instructions, configuration guidance, and a cookbook section on how to handle specific use cases.