Question

I am trying to return a JSON object from a function using the JSON jQuery plugin (http://code.google.com/p/jquery-json/) but after returning the object from the function, it becomes undefined.

$(document).ready(function() {

    var $calendar = $('#calendar');

    $calendar.weekCalendar({

        ...

        data : function(start, end, callback) {
            var datas = getEventData();
            alert(datas); // Undefined???
        }
    });

If I inspect the object before returning it, it is defined.

function getEventData() {
        var dataString = "minDate="+ minDate/1000  + "&maxDate=" + maxDate/1000;
        //alert(dataString);return false;
        $.ajax({
                type: "POST",
                url: "busker_ops.php",
                data: dataString,
                dataType: "json",
                success: function(data) {
                    if(data != null) {
                            var jsonArray = new Array();
                            var jsonObj = {};
                            for(var i = data.length - 1; i >= 0; --i) {

                                var o = data[i];
                                var set_id = o.set_id;
                                var start = o.startOrig;
                                var end = o.endOrig;
                                var title = o.title;
                                var deets = o.deets;
                                jsonObj = 
                                    {
                                        "id":parseInt(set_id),
                                        "start":$("#calendar").weekCalendar("formatDate", new Date(start), "c"),
                                        "end":$("#calendar").weekCalendar("formatDate", new Date(end), "c"),
                                        "title":title,
                                        "body":deets
                                    };
                                jsonArray[i] = jsonObj;
                            }
                            alert($.toJSON(jsonArray)); // Defined!
                            return ($.toJSON(jsonArray));
                    } else {
                    }
                }
        });
    }

Any idea what I’m missing here?

Answer 1

function getEventData() {
  function local() {
    console.log(42);
    return 42;
  }

  local();
}

Your missing the fact that the outer function returns undefined. And that’s why your answer is undefined.

Your also doing asynchronous programming wrong. You want to use callbacks. There are probably 100s of duplicate questions about this exact problem.