POST json data via ajax sends an empty array

Question

I'm trying to post data via ajax, this is my info:

    var jsondata =
                {"address" : [
                { "id": addid, "streetaddress": streetaddress, "city": city, "state": state,  "zipcode": zipcode, "latitude": latitude},
            ]   
            };  

    var jsontosend = JSON.stringify(jsondata, null, 2);

ajax function:

    $.ajax({
                type: "POST",
                url: "process.php",
                contentType: "application/json; charset=utf-8",
                dataType: "JSON",
                data: jsontosend,
                success: function(msg){
                   alert(msg);
                          }
             });

            return false;

            alert('Data sent');

}

on the php end, when i print_r($_POST) it just says

    array(0) {
    }

I'm alerting (jsontosend) and its showing me everything perfectly, as well as in firebug using post mothod, its showing all the params sent in a perfect clean manner.

The only way it passes any data is if I use GET method.

Any advice is greatly appreciated!

EDIT: adding POST data from firebug. this is whats being alerted from the alert function:

    {"address":[{"id":1473294,"streetaddress":"3784 Howard Ave","city":"Washington DC","state":"DC","zipcode":20895,"latitude":39.027820587}]}

this is what firebug is showing as whats being passed when using POST method:

    myData=%7B%0A++++%22address%22%3A+%5B%0A++++++++%7B%0A++++++++++++%22id%22%3A+76076%2C%0A++++++++++++%22streetaddress%22%3A+%223784+Howard+Ave%22%2C%0A++++++++++++%22city%22%3A+%22Washington+DC%22%2C%0A++++++++++++%22state%22%3A+%22DC%22%2C%0A++++++++++++%22zipcode%22%3A+20895%2C%0A++++++++++++%22latitude%22%3A+39.027820587%0A++++++++%7D%0A++++%5D%0A%7D

and this is the response for var_dump of $_POST:

    array(0) {

}

this is a var_dump of $_POST['myData']

    NULL

Answer 1

Taking contentType out is not a good idea. You DO want to send this data in JSON format. Key is to do what has been mentioned above, instead of trying to access the data on the receiving end (the target php file) with $data= $_POST it is critical to use $data = file_get_contents('php://input');

Here is an example of the entire round trip for a scenario with php and knockout.js:

JS (on requesting page):

function() {
   var payload = ko.toJSON({ YOUR KNOCKOUT OBJECT });
   jQuery.ajax({
            url: 'target.php',
            type: "POST",
            data: payload,
            datatype: "json",
            processData: false,
            contentType: "application/json; charset=utf-8",
            success: function (result) {
                alert(result);
            }
        });
 };

And then in target.php (the page receiving the request):

$data = file_get_contents('php://input');
$payload_jsonDecoded = json_decode($data

Answer 2

I'm skeptical of the way you're using the contentType property. Try taking out contentType. The default content type is application/x-www-form-urlencoded (http://api.jquery.com/jQuery.ajax/).

Also, use something like {mydata: jsontosend} for your data property.

$.ajax({
            type: "POST",
            url: "process.php",
            //contentType: "application/json; charset=utf-8",
            dataType: "JSON",
            data: {mydata: jsontosend},
            success: function(msg){
               alert(msg);
                      }
         });