text: var map = new ol.Map({
    layers: [
      new ol.layer.Tile({
        source: new ol.source.OSM()
      })
    ],
    target: 'map',
    view: new ol.View({
      projection: 'EPSG:3857',
      center: [0, 0],
      zoom: 1
    })
  });
  
  
  var queryInput = document.getElementById('epsg-query');
  var searchButton = document.getElementById('epsg-search');
  var resultSpan = document.getElementById('epsg-result');
  var renderEdgesCheckbox = document.getElementById('render-edges');
  
  function setProjection(code, name, proj4def, bbox) {
    if (code === null || name === null || proj4def === null || bbox === null) {
      resultSpan.innerHTML = 'Nothing usable found, using EPSG:3857...';
      map.setView(new ol.View({
        projection: 'EPSG:3857',
        center: [0, 0],
        zoom: 1
      }));
      return;
    }
  
    resultSpan.innerHTML = '(' + code + ') ' + name;
  
    var newProjCode = 'EPSG:' + code;
    proj4.defs(newProjCode, proj4def);
    var newProj = ol.proj.get(newProjCode);
    var fromLonLat = ol.proj.getTransform('EPSG:4326', newProj);
  
    // very approximate calculation of projection extent
    var extent = ol.extent.applyTransform(
        [bbox[1], bbox[2], bbox[3], bbox[0]], fromLonLat);
    newProj.setExtent(extent);
    var newView = new ol.View({
      projection: newProj
    });
    map.setView(newView);
    newView.fit(extent);
  }
  
  
  function search(query) {
    resultSpan.innerHTML = 'Searching ...';
    fetch('https://epsg.io/?format=json&q=' + query).then(function(response) {
      return response.json();
    }).then(function(json) {
      var results = json['results'];
      if (results && results.length > 0) {
        for (var i = 0, ii = results.length; i < ii; i++) {
          var result = results[i];
          if (result) {
            var code = result['code'], name = result['name'],
                proj4def = result['proj4'], bbox = result['bbox'];
            if (code && code.length > 0 && proj4def && proj4def.length > 0 &&
                bbox && bbox.length == 4) {
              setProjection(code, name, proj4def, bbox);
              return;
            }
          }
        }
      }
      setProjection(null, null, null, null);
    });
  }
  
  
  /**
   * Handle click event.
   * @param {Event} event The event.
   */
  searchButton.onclick = function(event) {
    search(queryInput.value);
    event.preventDefault();
  };
  
  
  /**
   * Handle change event.
   */
  renderEdgesCheckbox.onchange = function() {
    map.getLayers().forEach(function(layer) {
      if (layer instanceof ol.layer.Tile) {
        var source = layer.getSource();
        if (source instanceof ol.source.TileImage) {
          source.setRenderReprojectionEdges(renderEdgesCheckbox.checked);
        }
      }
    });
  };
  