Layer Groups

Click on layer nodes below to change their properties.
  • OSM layer
  • Layer group
    • Food insecurity layer
    • World borders layer

Example of a map with layer group.

Example of a map with layer group.

<!DOCTYPE html>
<html>
  <head>
    <title>Layer Groups</title>
    <link rel="stylesheet" href="https://openlayers.org/en/v4.6.4/css/ol.css" type="text/css">
    <!-- The line below is only needed for old environments like Internet Explorer and Android 4.x -->
    <script src=""></script>
    <script src="https://openlayers.org/en/v4.6.4/build/ol.js"></script>
    <script src="https://code.jquery.com/jquery-2.2.3.min.js"></script>
    <style>
      #layertree li > span {
        cursor: pointer;
      }    </style>
  </head>
  <body>
    <div id="map" class="map"></div>
    <div id="layertree">
      <h5>Click on layer nodes below to change their properties.</h5>
      <ul>
        <li><span>OSM layer</span>
          <fieldset id="layer0">
            <label class="checkbox" for="visible0">
              <input id="visible0" class="visible" type="checkbox"/>visibility
            </label>
            <label>opacity</label>
            <input class="opacity" type="range" min="0" max="1" step="0.01"/>
          </fieldset>
        </li>
        <li><span>Layer group</span>
          <fieldset id="layer1">
            <label class="checkbox" for="visible1">
              <input id="visible1" class="visible" type="checkbox"/>visibility
            </label>
            <label>opacity</label>
            <input class="opacity" type="range" min="0" max="1" step="0.01"/>
          </fieldset>
          <ul>
            <li><span>Food insecurity layer</span>
              <fieldset id="layer10">
                <label class="checkbox" for="visible10">
                  <input id="visible10" class="visible" type="checkbox"/>visibility
                </label>
                <label>opacity</label>
                <input class="opacity" type="range" min="0" max="1" step="0.01"/>
              </fieldset>
            </li>
            <li><span>World borders layer</span>
              <fieldset id="layer11">
                <label class="checkbox" for="visible11">
                  <input id="visible11" class="visible" type="checkbox"/>visibility
                </label>
                <label>opacity</label>
                <input class="opacity" type="range" min="0" max="1" step="0.01"/>
              </fieldset>
            </li>
          </ul>
        </li>
      </ul>
    </div>
    <script>
      var map = new ol.Map({
        layers: [
          new ol.layer.Tile({
            source: new ol.source.OSM()
          }), new ol.layer.Group({
            layers: [
              new ol.layer.Tile({
                source: new ol.source.TileJSON({
                  url: 'https://api.tiles.mapbox.com/v3/mapbox.20110804-hoa-foodinsecurity-3month.json?secure',
                  crossOrigin: 'anonymous'
                })
              }),
              new ol.layer.Tile({
                source: new ol.source.TileJSON({
                  url: 'https://api.tiles.mapbox.com/v3/mapbox.world-borders-light.json?secure',
                  crossOrigin: 'anonymous'
                })
              })
            ]
          })
        ],
        target: 'map',
        view: new ol.View({
          center: ol.proj.fromLonLat([37.40570, 8.81566]),
          zoom: 4
        })
      });

      function bindInputs(layerid, layer) {
        var visibilityInput = $(layerid + ' input.visible');
        visibilityInput.on('change', function() {
          layer.setVisible(this.checked);
        });
        visibilityInput.prop('checked', layer.getVisible());

        var opacityInput = $(layerid + ' input.opacity');
        opacityInput.on('input change', function() {
          layer.setOpacity(parseFloat(this.value));
        });
        opacityInput.val(String(layer.getOpacity()));
      }
      map.getLayers().forEach(function(layer, i) {
        bindInputs('#layer' + i, layer);
        if (layer instanceof ol.layer.Group) {
          layer.getLayers().forEach(function(sublayer, j) {
            bindInputs('#layer' + i + j, sublayer);
          });
        }
      });

      $('#layertree li > span').click(function() {
        $(this).siblings('fieldset').toggle();
      }).siblings('fieldset').hide();
    </script>
  </body>
</html>