Display form via Ajax - ajax

Question

Edit
Many questions on SO are about form submission via Ajax (this one is very popular) but not about how to display a form through an ajax call.
My question is about the part in bold: the user asks for a form -> ajaxCall -> displayForm -> user submit the form -> send the form to the controller -> validates form -> send response to the user (errors or not).
The question
The ajax call being a POST, $request->isMethod('POST') always returns true when doing an ajax call. Therefore if a new form is being requested through an ajax call, it will always be validated. I have enclosed the code below, the form is displayed ok, but the following error message is displayed in the form:
The CSRF token is invalid.
The problem is that the form is being validated during the ajax call requestion the form in the controller.
On a side note, submitting the form works well, and validation works well.
Does anyone know how to display a form via Ajax without having the blank new form being validated?
My code so far:
/**
* Display the message as well as the form to reply to that message
*
* #param Request $request
* #return Response
*/
public function viewMessageAction(Request $request)
{
//Forbid every request but jQuery's XHR
if (!$request->isXmlHttpRequest()){
return new Response('', 200, array('Content-Type' => 'application/json'));
}
//Retrieve the message from the request
$messageId = $request->request->get('messageId');
$message = $this->getMessageManager->getMessage($messageId);
//Creates the form to reply to the message
$form = $this->container->get('reply_form.factory')->create($message);
if ($request->isMethod('POST')) {
$form->bind($request);
if ($form->isValid()) {
//...
return $this->redirect($this->generateUrl('task_success'));
}
}
$answer =$this->container->get('templating')->renderResponse('AcmeMessageBundle:Message:message.html.twig', array(
'form' => $form->createView(),
'message' => $message
));
$response = new Response();
$response->headers->set('Content-type', 'application/json; charset=utf-8');
$response->setContent(json_encode($answer));
return $response;
}
EDIT: jQuery part:
<script type="text/javascript">
$(function(){
var myPath = ;//...
function getMessage(messageId){
$.ajax({
type: "POST",
url: myPath,
data: "messageId="+messageId,
success: function(returnData){
$('#message').html(returnData);
}
});
}
});
</script>

Answer 1

An ajax call doesnt always need to be POST. It could be GET, PUT or DELETE . So when you are making ajax call to get the form make it a GET request.
If you are using jquery here is how you do that
$.ajax({
url: "http://localhost/proj/url",
type:'GET'
})
If you are using Using XHR, you can specify the type in the open function
xhr.open( 'GET', URL)
PS: It will be a good idea to use JMS Serializer Service for serialization instead of json_encode

Answer 2

You might also be interessted in the FOSJsRoutingBundle, since it add a lot of comfort working with ajax and Symfony2 routes in general.