Export geoJSON data from Google Maps

Question

Is there built-in support or any library to export geoJSON data from the google.maps.Data layer or google.maps.Data.Feature or googl

Answer 1

A sample-function:

google.maps.Map.prototype.getGeoJson=function(callback){
  var geo={"type": "FeatureCollection","features": []},
      fx=function(g,t){

        var that  =[],
            arr,
            f     = {
                      MultiLineString :'LineString',
                      LineString      :'Point',
                      MultiPolygon    :'Polygon',
                      Polygon         :'LinearRing',
                      LinearRing      :'Point',
                      MultiPoint      :'Point'
                    };

        switch(t){
          case 'Point':
            g=(g.get)?g.get():g;
            return([g.lng(),g.lat()]);
            break;
          default:
            arr= g.getArray();
            for(var i=0;i

The function creates an object with the data. You may pass a callback as argument which will be executed with the object as argument.

Sample-call:

//map is the google.maps.Map-instance
map.getGeoJson(function(o){console.log(o)});

Demo: http://jsfiddle.net/doktormolle/5F88D/

Note: the Demo also stores circles, but circles are not supported in GeoJSON. As a workaround it stores circles as a POINT with a radius-property.

When a POINT with a radius-property will be loaded into the data-layer the demo hides the marker and creates a circle based on geometry and the radius-property instead.

---

: there is now a built-in method available for geoJSON-export: google.maps.Data.toGeoJson()

See Save Map Instance outside of Google Maps for an example