FTTH/src/WebserviceBundle/Controller/WebserviceController.php

<?php

namespace WebserviceBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\JsonResponse;

class WebserviceController extends Controller
{

    public function getClientListAction(Request $request)
    {
        $query = $request->query->get('q', '');

        $choice_loader = $this->get('webservice.client.choiceloader');
        $choice_list = $choice_loader->getChoicesList($query);
        $list_values = [];

        foreach ($choice_list as $label => $id) {
            $list_values[] = [
                'id' => $id,
                'text' => $label
            ];
        }

        $response = new JsonResponse();
        $response->setData(['results' => $list_values]);

        return $response;
    }

}