Getting Properties With Event Handlers

This example listens for the zoom_changed event and updates an info window when the zoom level changes.

Read the documentation.

TypeScript

function initMap(): void {
  const originalMapCenter = new google.maps.LatLng(-25.363882, 131.044922);
  const map = new google.maps.Map(
    document.getElementById("map") as HTMLElement,
    {
      zoom: 4,
      center: originalMapCenter,
    }
  );

  const infowindow = new google.maps.InfoWindow({
    content: "Change the zoom level",
    position: originalMapCenter,
  });

  infowindow.open(map);

  map.addListener("zoom_changed", () => {
    infowindow.setContent("Zoom: " + map.getZoom()!);
  });
}

JavaScript

function initMap() {
  const originalMapCenter = new google.maps.LatLng(-25.363882, 131.044922);
  const map = new google.maps.Map(document.getElementById("map"), {
    zoom: 4,
    center: originalMapCenter,
  });
  const infowindow = new google.maps.InfoWindow({
    content: "Change the zoom level",
    position: originalMapCenter,
  });

  infowindow.open(map);
  map.addListener("zoom_changed", () => {
    infowindow.setContent("Zoom: " + map.getZoom());
  });
}

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;
}

HTML

<!DOCTYPE html>
<html>
  <head>
    <title>Getting Properties With Event Handlers</title>
    <script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script>
    <link rel="stylesheet" type="text/css" href="./style.css" />
    <script src="./index.js"></script>
  </head>
  <body>
    <div id="map"></div>

    <!-- Async script executes immediately and must be after any DOM elements used in callback. -->
    <script
      src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initMap&v=weekly"
      async
    ></script>
  </body>
</html>
function initMap() { const originalMapCenter = new google.maps.LatLng(-25.363882, 131.044922); const map = new google.maps.Map(document.getElementById("map"), { zoom: 4, center: originalMapCenter, }); const infowindow = new google.maps.InfoWindow({ content: "Change the zoom level", position: originalMapCenter, }); infowindow.open(map); map.addListener("zoom_changed", () => { infowindow.setContent("Zoom: " + map.getZoom()); }); }
/* 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; }
<!DOCTYPE html> <html> <head> <title>Getting Properties With Event Handlers</title> <script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script> <!-- jsFiddle will insert css and js --> </head> <body> <div id="map"></div> <!-- Async script executes immediately and must be after any DOM elements used in callback. --> <script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyB41DRUbKWJHPxaFjMAwdrzWzbVKartNGg&callback=initMap&v=weekly&channel=2" async ></script> </body> </html>

Try Sample

Clone Sample

Git and Node.js are required to run this sample locally. Follow these instructions to install Node.js and NPM. The following commands clone, install dependencies and start the sample application.

  git clone -b sample-event-properties https://github.com/googlemaps/js-samples.git
  cd js-samples
  npm i
  npm start

Other samples can be tried by switching to any branch beginning with sample-SAMPLE_NAME.

  git checkout sample-SAMPLE_NAME
  npm i
  npm start