JSTS Integration

This example uses OpenLayers v4.0.1. The latest is v.

#### JSTS Integration

Example on how to use JSTS with OpenLayers.

Example showing the integration of JSTS with OpenLayers.

Related API documentation:

- ol.Map
,
- ol.View
,
- ol.format.GeoJSON
,
- ol.layer.Tile
,
- ol.layer.Vector
,
- ol.proj
,
- ol.source.OSM
,
- ol.source.Vector

Copy Edit
JSTS Integration Example on how to use JSTS with OpenLayers. // this example uses JSTS for which we don't have an externs file. var source = new ol.source.Vector(); fetch('https://openlayers.org/en/v4.0.1/examples/data/geojson/roads-seoul.geojson').then(function(response) { return response.json(); }).then(function(json) { var format = new ol.format.GeoJSON(); var features = format.readFeatures(json, {featureProjection: 'EPSG:3857'}); var parser = new jsts.io.OL3Parser(); for (var i = 0; i < features.length; i++) { var feature = features[i]; // convert the OpenLayers geometry to a JSTS geometry var jstsGeom = parser.read(feature.getGeometry()); // create a buffer of 40 meters around each line var buffered = jstsGeom.buffer(40); // convert back from JSTS and replace the geometry on the feature feature.setGeometry(parser.write(buffered)); } source.addFeatures(features); }); var vectorLayer = new ol.layer.Vector({ source: source }); var rasterLayer = new ol.layer.Tile({ source: new ol.source.OSM() }); var map = new ol.Map({ layers: [rasterLayer, vectorLayer], target: document.getElementById('map'), view: new ol.View({ center: ol.proj.fromLonLat([126.979293, 37.528787]), zoom: 15 }) }); <div id="map" class="map"></div>

    <!DOCTYPE html>
    <html>
      <head>
        <title>JSTS Integration</title>
        <link rel="stylesheet" href="https://openlayers.org/en/v4.0.1/css/ol.css" type="text/css">
        <!-- The line below is only needed for old environments like Internet Explorer and Android 4.x -->
        <script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=requestAnimationFrame,Element.prototype.classList,URL"></script>
        <script src="https://openlayers.org/en/v4.0.1/build/ol.js"></script>
        <script src="https://cdn.rawgit.com/bjornharrtell/jsts/gh-pages/1.2.0/jsts.min.js"></script>
      </head>
      <body>
        <div id="map" class="map"></div>
        <script>
          // this example uses JSTS for which we don't have an externs file.
          var source = new ol.source.Vector();
          fetch('https://openlayers.org/en/v4.0.1/examples/data/geojson/roads-seoul.geojson').then(function(response) {
            return response.json();
          }).then(function(json) {
            var format = new ol.format.GeoJSON();
            var features = format.readFeatures(json, {featureProjection: 'EPSG:3857'});

            var parser = new jsts.io.OL3Parser();

            for (var i = 0; i < features.length; i++) {
              var feature = features[i];
              // convert the OpenLayers geometry to a JSTS geometry
              var jstsGeom = parser.read(feature.getGeometry());

              // create a buffer of 40 meters around each line
              var buffered = jstsGeom.buffer(40);

              // convert back from JSTS and replace the geometry on the feature
              feature.setGeometry(parser.write(buffered));
            }

            source.addFeatures(features);
          });
          var vectorLayer = new ol.layer.Vector({
            source: source
          });

          var rasterLayer = new ol.layer.Tile({
            source: new ol.source.OSM()
          });

          var map = new ol.Map({
            layers: [rasterLayer, vectorLayer],
            target: document.getElementById('map'),
            view: new ol.View({
              center: ol.proj.fromLonLat([126.979293, 37.528787]),
              zoom: 15
            })
          });
        </script>
      </body>
    </html>