Openlayers 3 how to add kml using a string variable?

Question

Is there any way to add a kml vector in openlayer 3 like this but the kml is from a string variable?

  var vector = new ol.layer.Vector({
            source: new ol.source.Vector({
              url: 'https://openlayers.org/en/v4.2.0/examples/data/kml/2012-02-10.kml',
              format: new ol.format.KML()
            })
          });

I tried this code but it doesn't work.

var kmlString = result;
var features = new ol.format.KML().readFeatures(kmlString);

var KMLvectorSource = new ol.source.Vector({
    features: features
});


var KMLvector = new ol.layer.Vector({ source: KMLvectorSource });

//KMLvector.addFeatures(features);
map.addLayer(KMLvector);

Thanks in advance.

Answer 1

You are missing the projection definition and transformation for your kml features. The kml features exist in https://openlayers.org/en/v4.2.0/examples/data/kml/2012-02-10.kml are projected in EPSG:4326 while your map is projected in EPSG:3857. For kml is common to be projected in 4326 so in most cases the EPSG code for kml should be 4326.

Now back to your problem. Change this line:

var features = new ol.format.KML().readFeatures(kmlString);

To this:

var features = new ol.format.KML().readFeatures(kmlString,{ dataProjection:'EPSG:4326', featureProjection:'EPSG:3857' });