Route search function with more than 8 waypoints using Google Maps API v3

gistfile1.js

function searchLongRoute(waypoints) {
  var route;
  var unit = 10;
  var unit_num = Math.ceil((waypoints.length+Math.ceil(waypoints.length/unit)-1)/unit);

  for (var start_num = 0; start_num < waypoints.length-1;) {
    var s = waypoints[start_num];
    var next_start = ((waypoints.length>=start_num+unit)?(start_num+unit):(waypoints.length))-1;
    var e = waypoints[next_start];
    var w = waypoints.slice(start_num+1, next_start);
    
    direction.route({
      'origin': s.location,
      'destination': e.location,
      'travelMode': tMode,
      'waypoints': w,
      'avoidHighways': true,
      'avoidTolls': true
    }, function(ret, st){
      if (st == google.maps.DirectionsStatus.OK) {
        if (route) {
          route.routes[0].legs = route.routes[0].legs.concat(ret.routes[0].legs);
          route.routes[0].overview_path = route.routes[0].overview_path.concat(ret.routes[0].overview_path);
          route.routes[0].bounds = route.routes[0].bounds.extend(ret.routes[0].bounds.getNorthEast());
          route.routes[0].bounds = route.routes[0].bounds.extend(ret.routes[0].bounds.getSouthWest());
        } else {
          route = ret;
        }
      } else {
        console.log(st);
      }
      if (!--unit_num) {
        renderer.setMap(map);
        renderer.setDirections(route);
      }
    });
    
    start_num = next_start;
  }
}

var direction = new google.maps.DirectionsService();
var renderer  = new google.maps.DirectionsRenderer();

Hey frah,

I looking few days for a solution to handle more then 8 waypoints with no result :( Can You provide more info how to use Your funcion. I will be really thankfull for that.