TopoJSON

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

#### TopoJSON

Demonstrates rendering of features from a TopoJSON topology.

This example uses a vector layer with `ol.format.TopoJSON` for rendering features from TopoJSON.

Related API documentation:

- ol.Map
,
- ol.View
,
- ol.format.TopoJSON
,
- ol.layer.Tile
,
- ol.layer.Vector
,
- ol.source.TileJSON
,
- ol.source.Vector
,
- ol.style.Fill
,
- ol.style.Stroke
,
- ol.style.Style

Copy Edit
TopoJSON Demonstrates rendering of features from a TopoJSON topology. var raster = new ol.layer.Tile({ source: new ol.source.TileJSON({ url: 'https://api.tiles.mapbox.com/v3/mapbox.world-dark.json?secure' }) }); var style = new ol.style.Style({ fill: new ol.style.Fill({ color: 'rgba(255, 255, 255, 0.6)' }), stroke: new ol.style.Stroke({ color: '#319FD3', width: 1 }) }); var vector = new ol.layer.Vector({ source: new ol.source.Vector({ url: 'https://openlayers.org/en/v4.0.1/examples/data/topojson/world-110m.json', format: new ol.format.TopoJSON(), overlaps: false }), style: function(feature) { // don't want to render the full world polygon, which repeats all countries return feature.getId() !== undefined ? style : null; } }); var map = new ol.Map({ layers: [raster, vector], target: 'map', view: new ol.View({ center: [0, 0], zoom: 1 }) }); <div id="map" class="map"></div>

    <!DOCTYPE html>
    <html>
      <head>
        <title>TopoJSON</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>
      </head>
      <body>
        <div id="map" class="map"></div>
        <script>
          var raster = new ol.layer.Tile({
            source: new ol.source.TileJSON({
              url: 'https://api.tiles.mapbox.com/v3/mapbox.world-dark.json?secure'
            })
          });

          var style = new ol.style.Style({
            fill: new ol.style.Fill({
              color: 'rgba(255, 255, 255, 0.6)'
            }),
            stroke: new ol.style.Stroke({
              color: '#319FD3',
              width: 1
            })
          });

          var vector = new ol.layer.Vector({
            source: new ol.source.Vector({
              url: 'https://openlayers.org/en/v4.0.1/examples/data/topojson/world-110m.json',
              format: new ol.format.TopoJSON(),
              overlaps: false
            }),
            style: function(feature) {
              // don't want to render the full world polygon, which repeats all countries
              return feature.getId() !== undefined ? style : null;
            }
          });

          var map = new ol.Map({
            layers: [raster, vector],
            target: 'map',
            view: new ol.View({
              center: [0, 0],
              zoom: 1
            })
          });
        </script>
      </body>
    </html>