Unable to Get and decode the JSON data sent to server using ajax corova

Question

I am trying to pass a json data from mobile application through ajax call. My Ajax call is

$.ajax({
        type: 'GET',
        data: postData,
        jsonp: "callback",
        dataType: 'jsonp',
        url: 'http://*****.*****.org.in/qr.php',
        success: function(data){
            $ionicLoading.hide();
            console.log(data);
            alert('Your data was successfully added');
            $location.path('/home');
        },
        error: function(data,error){
            $ionicLoading.hide();
            console.log(error);
            alert('There was an error adding your data');
        }
    });

The value in postData is

{ event_name: "Contraptions" event_type: "Engineering" participant_type: "Individual" place: "Third" qr1: "amsds" qr2: "" qr3: "" qr4: "" qr5: "" round: "3" teamname: ""}

I could see the postData json in console.

My server side Code qr.php is

    <?
try
{
$callback = isset($_GET['callback']) ? preg_replace('/[^a-z0-9$_]/si', '', $_GET['callback']) : false;
header('Content-Type: ' . ($callback ? 'application/javascript' : 'application/json') . ';charset=UTF-8');
$json = json_decode('postData');
$data = array('status' => $json );
echo ($callback ? $callback . '(' : '') . json_encode($data) . ($callback ? ')' : '');

}
catch(Exception $e)
{
echo $e;
}
?>

But the $json which is decoded is NULL. How should I get the JSON data and decode that JSON that was passed from client ?????

Answer 1

Create a correct object in JavaScript

fi

var data = {event_name: "Contraptions", event_type: "Engineering", participant_type: "Individual"};

and use

data : {postData: JSON.stringify(data)};

in the ajax call.