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Data Layer: Event Handling

This example uses a data layer to dynamically display information about a KML feature object when under the mouse cursor.

Read the documentation.

JavaScript

var map;
function initMap() {
  map = new google.maps.Map(document.getElementById("map"), {
    zoom: 4,
    center: { lat: -28, lng: 137 }
  });

  // Load GeoJSON.
  map.data.loadGeoJson(
    "https://storage.googleapis.com/maps-devrel/google.json"
  );

  // Add some style.
  map.data.setStyle(function(feature) {
    return /** @type {google.maps.Data.StyleOptions} */ ({
      fillColor: feature.getProperty("color"),
      strokeWeight: 1
    });
  });

  // Set mouseover event for each feature.
  map.data.addListener("mouseover", function(event) {
    document.getElementById("info-box").textContent = event.feature.getProperty(
      "letter"
    );
  });
}

CSS

/* Always set the map height explicitly to define the size of the div
       * element that contains the map. */
#map {
  height: 100%;
}

/* Optional: Makes the sample page fill the window. */
html,
body {
  height: 100%;
  margin: 0;
  padding: 0;
}

#info-box {
  background-color: white;
  border: 1px solid black;
  bottom: 30px;
  height: 20px;
  padding: 10px;
  position: absolute;
  left: 30px;
}

HTML

<!DOCTYPE html>
<html>
  <head>
    <title>Data Layer: Event Handling</title>
    <script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script>
    <script
      src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initMap&libraries=&v=weekly"
      defer
    ></script>
    <link rel="stylesheet" type="text/css" href="./style.css" />
    <script src="./app.js"></script>
  </head>
  <body>
    <div id="map"></div>
    <div id="info-box">?</div>
  </body>
</html>

All

<!DOCTYPE html>
<html>
  <head>
    <title>Data Layer: Event Handling</title>
    <script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script>
    <script
      src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initMap&libraries=&v=weekly"
      defer
    ></script>
    <style type="text/css">
      /* Always set the map height explicitly to define the size of the div
       * element that contains the map. */
      #map {
        height: 100%;
      }

      /* Optional: Makes the sample page fill the window. */
      html,
      body {
        height: 100%;
        margin: 0;
        padding: 0;
      }

      #info-box {
        background-color: white;
        border: 1px solid black;
        bottom: 30px;
        height: 20px;
        padding: 10px;
        position: absolute;
        left: 30px;
      }
    </style>
    <script>
      (function(exports) {
        "use strict";

        function initMap() {
          exports.map = new google.maps.Map(document.getElementById("map"), {
            zoom: 4,
            center: {
              lat: -28,
              lng: 137
            }
          }); // Load GeoJSON.

          exports.map.data.loadGeoJson(
            "https://storage.googleapis.com/maps-devrel/google.json"
          ); // Add some style.

          exports.map.data.setStyle(function(feature) {
            return (
              /** @type {google.maps.Data.StyleOptions} */
              ({
                fillColor: feature.getProperty("color"),
                strokeWeight: 1
              })
            );
          }); // Set mouseover event for each feature.

          exports.map.data.addListener("mouseover", function(event) {
            document.getElementById(
              "info-box"
            ).textContent = event.feature.getProperty("letter");
          });
        }

        exports.initMap = initMap;
      })((this.window = this.window || {}));
    </script>
  </head>
  <body>
    <div id="map"></div>
    <div id="info-box">?</div>
  </body>
</html>
(function(exports) { "use strict"; function initMap() { exports.map = new google.maps.Map(document.getElementById("map"), { zoom: 4, center: { lat: -28, lng: 137 } }); // Load GeoJSON. exports.map.data.loadGeoJson( "https://storage.googleapis.com/maps-devrel/google.json" ); // Add some style. exports.map.data.setStyle(function(feature) { return ( /** @type {google.maps.Data.StyleOptions} */ ({ fillColor: feature.getProperty("color"), strokeWeight: 1 }) ); }); // Set mouseover event for each feature. exports.map.data.addListener("mouseover", function(event) { document.getElementById( "info-box" ).textContent = event.feature.getProperty("letter"); }); } exports.initMap = initMap; })((this.window = this.window || {}));
/* Always set the map height explicitly to define the size of the div * element that contains the map. */ #map { height: 100%; } /* Optional: Makes the sample page fill the window. */ html, body { height: 100%; margin: 0; padding: 0; } #info-box { background-color: white; border: 1px solid black; bottom: 30px; height: 20px; padding: 10px; position: absolute; left: 30px; }
<!DOCTYPE html> <html> <head> <title>Data Layer: Event Handling</title> <script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script> <script src="https://maps.googleapis.com/maps/api/js?key=&callback=initMap&libraries=&v=weekly" defer ></script> <!-- jsFiddle will insert css and js --> </head> <body> <div id="map"></div> <div id="info-box">?</div> </body> </html>