jquery callback function not being called

Question

here is my code, the cb function does not get called from within the route function

function calcRoute(directionsService, data, i, cb) {
  var start;
  var end;
  var waypts = [];
  var date = data[i][0].rotaDate;
  var batches = [];
  var itemsPerBatch = 10; // google API max - 1 start, 1 stop, and 8 waypoints
  var itemsCounter = 0;
  var wayptsExist = 0;

  while (wayptsExist != data[i].length) {
    var subBatch = [];
    var subitemsCounter = 0;

    for (var j = itemsCounter; j < data[i].length; j++) {
      subitemsCounter++;
      var waypoint = new google.maps.LatLng(data[i][j].userLat, data[i][j].userLng);


      subBatch.push({
        location: waypoint,
        stopover: true
      });
      if (subitemsCounter == itemsPerBatch)
        break;
    }

    itemsCounter += subitemsCounter;
    batches.push(subBatch);
    //if(itemsCounter < data[i].length)
    wayptsExist = itemsCounter; // &amp;lt; data[i].length;
    // If it runs again there are still points. Minus 1 before continuing to
    // start up with end of previous tour leg
    itemsCounter--;

  }

  var combinedResults;
  var unsortedResults = [{}]; // to hold the counter and the results themselves as they come back, to later sort
  var directionsResultsReturned = 0;

  for (var k = 0; k < batches.length; k++) {
    var lastIndex = batches[k].length - 1;
    var start = batches[k][0].location;
    var end = batches[k][lastIndex].location;

    // trim first and last entry from array
    var waypts = [];
    waypts = batches[k];
    waypts.splice(0, 1);
    waypts.splice(waypts.length - 1, 1);
    var request = {
      origin: start,
      destination: end,
      waypoints: waypts,
      travelMode: window.google.maps.TravelMode.DRIVING
    };


    directionsService.route(request, function(result, status) {

      if (status == window.google.maps.DirectionsStatus.OK) {

        var unsortedResult = {
          order: k,
          result: result
        };
        unsortedResults.push(unsortedResult);

        directionsResultsReturned++;

        if (directionsResultsReturned == batches.length) // we've received all the results. put to map
        {
          // sort the returned values into their correct order
          unsortedResults.sort(function(a, b) {
            return parseFloat(a.order) - parseFloat(b.order);
          });
          var count = 0;
          var totalDist = 0;
          var totalTime = 0;
          for (var key in unsortedResults) {
            if (unsortedResults[key].result != null) {
              if (unsortedResults.hasOwnProperty(key)) {
                if (count == 0) // first results. new up the combinedResults object
                  combinedResults = unsortedResults[key].result;
                else {
                  // only building up legs, overview_path, and bounds in my consolidated object. This is not a complete
                  // directionResults object, but enough to draw a path on the map, which is all I need


                  combinedResults.routes[0].legs = combinedResults.routes[0].legs.concat(unsortedResults[key].result.routes[0].legs);
                  combinedResults.routes[0].overview_path = combinedResults.routes[0].overview_path.concat(unsortedResults[key].result.routes[0].overview_path);

                  combinedResults.routes[0].bounds = combinedResults.routes[0].bounds.extend(unsortedResults[key].result.routes[0].bounds.getNorthEast());
                  combinedResults.routes[0].bounds = combinedResults.routes[0].bounds.extend(unsortedResults[key].result.routes[0].bounds.getSouthWest());
                }
                count++;
              }
            }
          }
          var myroute = combinedResults.routes[0];
          for (i = 0; i < myroute.legs.length; i++) {
            totalDist += myroute.legs[i].distance.value;
            //totalTime += myroute.legs[i].duration.value;
          }
          totalDist = totalDist / 1000.

          //get result here
           cb();
        }
      } else {
        console.log('error ' + status);

      }
    });
    }       
}

this is the function that calls calRoute and passes the callback function in

function getMileage() {
  var data;

  var directionsService = new google.maps.DirectionsService();
  var url = '********/getdata.php';
  $.ajax({
    type: 'GET',
    url: url,
    //dataType: 'json',
    success: function(output) {

      data = $.parseJSON(output);
      var count = 0;
      var count2 = -1;
      var next = true;

      while (count != data.length) {
        if (next == true) {
          next = false;
          calcRoute(directionsService, data, count, function() {
            next = true;
          });
          count++;
        }
      }
    }
  });
}

this answer suggest i can do this but it is not working for me

Answer 1

You have a typo in your function call.

Wrong

      totalDist = totalDist / 1000.

      //get result here
       cb();

Right

      totalDist = totalDist / 1000;

      //get result here
       cb();