WMS Time

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

#### WMS Time

Example of smooth tile transitions when changing the time dimension of a tiled WMS layer.

Demonstrates smooth reloading of layers when changing the time dimension continously. Data shown: IEM generated CONUS composite of NWS NEXRAD WSR-88D level III base reflectivity.

Related API documentation:

- ol.Map
,
- ol.View
,
- ol.extent
,
- ol.layer.Tile
,
- ol.proj
,
- ol.source.Stamen
,
- ol.source.TileWMS

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WMS Time Example of smooth tile transitions when changing the time dimension of a tiled WMS layer. function threeHoursAgo() { return new Date(Math.round(Date.now() / 3600000) * 3600000 - 3600000 * 3); } var extent = ol.proj.transformExtent([-126, 24, -66, 50], 'EPSG:4326', 'EPSG:3857'); var startDate = threeHoursAgo(); var frameRate = 0.5; // frames per second var animationId = null; var layers = [ new ol.layer.Tile({ source: new ol.source.Stamen({ layer: 'terrain' }) }), new ol.layer.Tile({ extent: extent, source: new ol.source.TileWMS(/** @type {olx.source.TileWMSOptions} */ ({ attributions: ['Iowa State University'], url: 'https://mesonet.agron.iastate.edu/cgi-bin/wms/nexrad/n0r-t.cgi', params: {'LAYERS': 'nexrad-n0r-wmst'} })) }) ]; var map = new ol.Map({ layers: layers, target: 'map', view: new ol.View({ center: ol.extent.getCenter(extent), zoom: 4 }) }); function updateInfo() { var el = document.getElementById('info'); el.innerHTML = startDate.toISOString(); } function setTime() { startDate.setMinutes(startDate.getMinutes() + 15); if (startDate > Date.now()) { startDate = threeHoursAgo(); } layers[1].getSource().updateParams({'TIME': startDate.toISOString()}); updateInfo(); } setTime(); var stop = function() { if (animationId !== null) { window.clearInterval(animationId); animationId = null; } }; var play = function() { stop(); animationId = window.setInterval(setTime, 1000 / frameRate); }; var startButton = document.getElementById('play'); startButton.addEventListener('click', play, false); var stopButton = document.getElementById('pause'); stopButton.addEventListener('click', stop, false); updateInfo(); <div id="map" class="map"></div> <div role="group" aria-label="Animation controls"> <button id="play" type="button">Play</button> <button id="pause" type="button">Pause</button> <span id="info"></span> </div>

    <!DOCTYPE html>
    <html>
      <head>
        <title>WMS Time</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>
        <div role="group" aria-label="Animation controls">
          <button id="play" type="button">Play</button>
          <button id="pause" type="button">Pause</button>
          <span id="info"></span>
        </div>
        <script>
          function threeHoursAgo() {
            return new Date(Math.round(Date.now() / 3600000) * 3600000 - 3600000 * 3);
          }

          var extent = ol.proj.transformExtent([-126, 24, -66, 50], 'EPSG:4326', 'EPSG:3857');
          var startDate = threeHoursAgo();
          var frameRate = 0.5; // frames per second
          var animationId = null;

          var layers = [
            new ol.layer.Tile({
              source: new ol.source.Stamen({
                layer: 'terrain'
              })
            }),
            new ol.layer.Tile({
              extent: extent,
              source: new ol.source.TileWMS(/** @type {olx.source.TileWMSOptions} */ ({
                attributions: ['Iowa State University'],
                url: 'https://mesonet.agron.iastate.edu/cgi-bin/wms/nexrad/n0r-t.cgi',
                params: {'LAYERS': 'nexrad-n0r-wmst'}
              }))
            })
          ];
          var map = new ol.Map({
            layers: layers,
            target: 'map',
            view: new ol.View({
              center: ol.extent.getCenter(extent),
              zoom: 4
            })
          });

          function updateInfo() {
            var el = document.getElementById('info');
            el.innerHTML = startDate.toISOString();
          }

          function setTime() {
            startDate.setMinutes(startDate.getMinutes() + 15);
            if (startDate > Date.now()) {
              startDate = threeHoursAgo();
            }
            layers[1].getSource().updateParams({'TIME': startDate.toISOString()});
            updateInfo();
          }
          setTime();

          var stop = function() {
            if (animationId !== null) {
              window.clearInterval(animationId);
              animationId = null;
            }
          };

          var play = function() {
            stop();
            animationId = window.setInterval(setTime, 1000 / frameRate);
          };

          var startButton = document.getElementById('play');
          startButton.addEventListener('click', play, false);

          var stopButton = document.getElementById('pause');
          stopButton.addEventListener('click', stop, false);

          updateInfo();
        </script>
      </body>
    </html>