AJAX post JSON data from Javascript to Grails

Question

I'm trying to POST JSON formatted data from Javascript (using Prototype) to Grails. My Javascript code is:

var JSONObject = new Object;
    JSONObject.id = "23";
    JSONObject.name = "Test 1";
    JSONstring = JSON.stringify(JSONObject);



 var url = "${createLink(controller:'testController', action:'receiveJson')}";
    new Ajax.Request(url, {
      method:'post',
      contentType:'application/json',
      parameters:JSONstring,
      asynchronous:true,
      onSuccess: function (req) {
        sendInfoResponse(req.responseText);
      }
    });

and the code in my Grails controller is:

def receiveJson = {
  def json = request.JSON;
}

However, the 'json' variable appears to be empty in my tests. I'd be so grateful if someone could explain what I'm doing wrong. Many thanks.

Solution 1

In your Ajax.Request options change

parameters:JSONstring,

to

postBody:JSONstring,

The problem with using parameters is that it URL encodes the data so that the request body ends up looking like this:

%7B%22id%22%3A%2223%22%2C%22name%22%3A%22Test%201%22%7D&_=

Instead of the desired (which is what you get with postBody):

{"id":"23","name":"Test 1"}

Solution 2

Good question mfloryan - I was doing the testing manually, i.e. not as part of a unit or integration test.

Thanks very much for the help hvgotcodes. I made the changes to my code as you have suggested, but unfortunately to no avail. Interestingly, if I print request.JSON I get {}, whereas if I print request.json I get null.

EDIT: By 'printing' I mean using: request.JSON.toString()

EDIT: Thank you all so much for the help. Once I'd made the final change John Wagenleitne suggested the code began working properly. I'm very grateful indeed for all your help.

Comments

[Katrine]

Do you mean manual tests of the application or proper unit / integration tests?

[clockworkgeek]

Or you could do parameters:JSONObject, and leave out JSONstring entirely, Prototype will encode it correctly for you.

[user2433701]

@clockworkgeek that will encode the object as key/value pairs: id=23&name=Test%201&_=. You could access this as params.id and params.name in the controller, but it wont be parsed as a JSON object via request.JSON which is what I think the original poster wanted.

[JeffSea]

If the answer you referenced solved the problem, then you should mark the answer as accecpted.