Conviert un archivo i18n de Symfony en JSON

TranslateController.php

namespace AppBundle\Controller\api;

use FOS\RestBundle\Controller\FOSRestController;
use FOS\RestBundle\Routing\ClassResourceInterface;
use Nelmio\ApiDocBundle\Annotation\ApiDoc;
use Symfony\Component\HttpFoundation\JsonResponse;
use Symfony\Component\Yaml\Yaml;


class TranslateController extends FOSRestController implements ClassResourceInterface
{

    /**
     * Get array by locale
     *
     * @ApiDoc(
     *  resource = true,
     *  section="Translate",
     *  statusCodes = {
     *      200 = "Returned when successful",
     *      400 = "Returned when the page is not found"
     *  }
     * )
     * @param $part
     * @param $locale
     * @return JsonResponse
     */
    public function getLocaleAction($part, $locale)
    {

        $response = new JsonResponse();

        $response
            ->setData($this->convertYml($part, $locale))
            ->setStatusCode(200);

        return $response;
    }

    private function convertYml($part, $locale)
    {
        $file = $part . '.' . $locale . '.yml';

        try {
            $object = Yaml::parse(file_get_contents($this->get('kernel')->getRootDir() . "/Resources/translations/" . $file));

            return $object;

        } catch (\Exception $e) {

            return 'The file "' . $file . '" does not exist.';

        }

    }

}