How to return Javascript in Symfony2? - symfony

Question

Like on Ruby on Rails, you can return Javascript with some prerendering to dynamically update the client site through AJAX.
How do you return Javascript when calling some routes in Symfony2?
For example, when calling updateItemAppearanceAction through \item\{itemId}\update_appearance, return Javascript file updateItemAppearance.js.twig, with array("item"->$item)?
Thank you very much!

Answer 1

Within the action method called updateItemAppearanceAction:
Create a Rendered view
Instantiate a Response object, passing the rendered view in the Constructor.
Set the Content-Type in the Response Header of the Response Object's instance to text/javascript.
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
// example controller.
class DefaultController extends Controller
{
/**
* #Route("/updateItemAppearance.js", name="default_update_item_appearance_js")
*/
public function updateItemAppearanceAction()
{
$optionalParams = array('some'=>'param');
$renderedView = $this->renderView('AppBundle:Default:updateItemAppearance.js.twig'); // 1.
$response = new Response($renderedView, $optionalParams)); // 2.
$response->headers->set('Content-Type','text/javascript'); // 3.
return $response;
}
}
As a result, the javascript you write in updateItemAppearance.js.twig file can be embedded as a javascript file via the usual means.
<script src="/updateItemAppearance.js"></script>
Or using the twig path helper.
<script src="{{ path('default_update_item_appearance_js') }}"></script>

Answer 2

Well if you want to return data for your javascript you could do this in your "updateItemAppearance.js.twig"
var javascriptVar = "{{twigVar|json_encode()|raw('js')}}";
If you're using the JMSSerializer you could do
var javascriptVar = "{{twigVar|serialize('json')|raw('js') }}";
More info: twig docs, jms serializer docs