Google map waypoints from geoJSON

Question

I want to load an itinerary from a geoJSON file. For the moment, it works, but only with two points.

But I need to add 4 or 5 waypoints. My code only read the two first

Answer 1

The problem is that you can't access the FeatureCollection where a feature belongs to. There is also no event that will fire when the parsing of the geoJSON has been finished(when the addfeature-event fires you'll never know if it's the last time for the particular FeatureCollection)

You may store additional properties for the features, e.g. the number of waypoints.

sample-JSON(including other properties to define e.g. if a point is a waypoint, origin or destination or when it's a waypoint the index of the waypoint )

{
"type": "FeatureCollection",
"features": [
  {
    "type"        : "Feature",
    "properties"  : {route      :{"id"    :1,
                                  "type"  :"origin",
                                  "points":2
                                 }
                    },
    "geometry"    : {"type"       : "Point",
                     "coordinates":[8.528849, 52.030656]}
  },

  {
    "type"        : "Feature",
    "properties"  : {route        :{"id"    :1,
                                    "type"  :"destination",
                                    "points":2
                                   }
                    },
    "geometry"    : {"type"       : "Point",
                     "coordinates":[11.5819, 48.1351253]}
  },

  {
    "type": "Feature",
    "properties"  : {"route"      :{"id"    :1,
                                    "type"  :"waypoint",
                                    "index" :1,
                                    "points":2
                                   }
                    },
    "geometry"    : {"type"       : "Point",
                     "coordinates":[13.40495,52.52]}
  },

  {
    "type"        : "Feature",
    "properties"  : {route        :{"id":1,
                                    "type":"waypoint",
                                    "index":0,
                                    "points":2
                                   }
                    },
    "geometry"    : {"type"       : "Point",
                     "coordinates":[9.99368, 53.5510846]}
  }
]}

It stores the properties in a custom route-property.

The properties are:

• type(origin,destination or waypoint)
• id(some unique id for the route, by using the id you'll be able to define multiple routes)
• points(the number of waypoints defined for the route)
• index...used for type:waypoint(the index of the waypoint in the waypoints-array, starting with 0)

parsing of these properties:

 map.data.addListener('addfeature',function(e){
  var geo=  e.feature.getGeometry();
  if(geo.getType()==='Point' && e.feature.getProperty('route')){
    var id    = e.feature.getProperty('route').id,
        type  = e.feature.getProperty('route').type,
        points= e.feature.getProperty('route').points,
        data;
    //the routes will be stored as a property of map.data
    if(!map.data.get('routes')){
        map.data.set('routes',{});
    }
    if(!map.data.get('routes')[id]){
      map.data.get('routes')[id]={waypoints:[],points:points,origin:null,destination:null};
    }

    data= map.data.get('routes')[id];
    switch(type){
      case 'waypoint':
        data.points--;
        data.waypoints[e.feature.getProperty('route').index]={location:geo.get()};
       break;
      default:
        data[type]= geo.get();

    }
    if(!data.points && data.origin && data.destination){
      //parsing of the route is complete
      delete data.points;
      //run the callback, 
      //data is an object suitable to be used as DirectionsRequest
      //you only need to add the desired travelMode
      callback(data);
    }
  }
 });

Demo: http://jsfiddle.net/doktormolle/vupkbasc/