How to post JSON request from javascript to Django and receive an JSON answer?

Question

My Django view:

class Main(View):
def post(self, request, *args, **kwargs):
    obj = json.loads(request.raw_post_data)
    //do something with obj
    temp = Entry.objects.all();
    result = []
    for t in temp:
        result.append( (t.key,t.value) );
    return HttpResponse(json.dumps(result), content_type="application/json")

My javascript:

$.post("http://XXX/", JSON.stringify({}), function(data) {
              alert("OK");
            }, "json");

What firebug has to say:

POST http://193.0.96.129:8006/ 200 OK
Post Headers
Response headers
Content-Type    application/json
Date    Thu, 16 May 2013 00:00:28 GMT
Server  WSGIServer/0.1 Python/2.7.3
Request headers
Accept  application/json, text/javascript, */*; q=0.01
Accept-Encoding gzip, deflate
Accept-Language pl,en-us;q=0.7,en;q=0.3
Content-Length  2
Content-Type    application/x-www-form-urlencoded; charset=UTF-8
Host    XXX
Origin  null
User-Agent  Mozilla/5.0 (Windows NT 6.1; WOW64; rv:20.0) Gecko/20100101 Firefox/20.0

The data gets through to Django, but the success callback doesn't get called. Django server returns code 200, but in Firebug notification about the POST is red.

I tried multiple variations of the $.post call, none worked. If I use $.ajax call and specify error callback

error: function(xhr, textStatus, errorThrown) {
    alert("some error" + xhr.responseText+ " X " + textStatus + " X " + errorThrown);
},

all I get to know is that "error" happend (xhr.responseText == textStatus == "error").

Answer 1

It seems like I was trying to do a "Cross-Domain" call. I was testing running the .html file locally, trying to call my remote Django server. Changing path of POST destination to relative, and running the script through Django view fixed the problem.

Thank you Daniel, the Content-Length thing was my carelessness, I posted different view version then one that we see responding in Firebug (it was returning "{}" I think - I was trying to debug).