Page Summary
-
This example demonstrates how to use the
ElevationServiceto display the elevation of a clicked point on a map. -
It uses an infowindow to show the elevation at the clicked location, retrieved using the
getElevationForLocationsmethod. -
The sample code is provided in both TypeScript and JavaScript, with the JavaScript compiled from the TypeScript.
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Users can click on the map to see the elevation at the clicked point, and error handling is included in case the service fails.
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The HTML, CSS, and JavaScript code snippets are provided, along with options to try the sample in JSFiddle or Google Cloud Shell.
This example demonstrates the use of the ElevationService object.
Click the map to display the elevation at the clicked point. Read the
documentation.
TypeScript
async function init(): Promise<void> { const [{ InfoWindow }, { ElevationService }] = await Promise.all([ google.maps.importLibrary('maps'), google.maps.importLibrary('elevation'), ]); const mapElement = document.querySelector('gmp-map')!; const innerMap = mapElement.innerMap; const elevator = new ElevationService(); const infowindow = new InfoWindow(); infowindow.open(innerMap); // Add a listener for the click event. Display the elevation for the LatLng of // the click inside the infowindow. innerMap.addListener('click', (event: google.maps.MapMouseEvent) => { displayLocationElevation(event.latLng!, elevator, infowindow, innerMap); }); } function displayLocationElevation( location: google.maps.LatLng, elevator: google.maps.ElevationService, infowindow: google.maps.InfoWindow, map: google.maps.Map ) { // Format numeric values to two decimal places const formatter = new Intl.NumberFormat(undefined, { maximumFractionDigits: 2, }); // Initiate the location request elevator .getElevationForLocations({ locations: [location], }) .then(({ results }) => { if (results[0]) { const { elevation, location: resultLocation } = results[0]; infowindow.setPosition(resultLocation); infowindow.setContent( `The elevation at ${String(resultLocation)} <br>is ${formatter.format(elevation)} meters.` ); } else { infowindow.setPosition(location); infowindow.setContent('No results found'); } infowindow.open(map); }) .catch((e: unknown) => { infowindow.setContent( `Elevation service failed due to: ${String(e)}` ); }); } void init();
JavaScript
async function init() { const [{ InfoWindow }, { ElevationService }] = await Promise.all([ google.maps.importLibrary('maps'), google.maps.importLibrary('elevation'), ]); const mapElement = document.querySelector('gmp-map'); const innerMap = mapElement.innerMap; const elevator = new ElevationService(); const infowindow = new InfoWindow(); infowindow.open(innerMap); // Add a listener for the click event. Display the elevation for the LatLng of // the click inside the infowindow. innerMap.addListener('click', (event) => { displayLocationElevation(event.latLng, elevator, infowindow, innerMap); }); } function displayLocationElevation(location, elevator, infowindow, map) { // Format numeric values to two decimal places const formatter = new Intl.NumberFormat(undefined, { maximumFractionDigits: 2, }); // Initiate the location request elevator .getElevationForLocations({ locations: [location], }) .then(({ results }) => { if (results[0]) { const { elevation, location: resultLocation } = results[0]; infowindow.setPosition(resultLocation); infowindow.setContent( `The elevation at ${String(resultLocation)} <br>is ${formatter.format(elevation)} meters.` ); } else { infowindow.setPosition(location); infowindow.setContent('No results found'); } infowindow.open(map); }) .catch((e) => { infowindow.setContent( `Elevation service failed due to: ${String(e)}` ); }); } void init();
CSS
/* * Optional: Makes the sample page fill the window. */ html, body { height: 100%; margin: 0; padding: 0; } gmp-map { height: 100%; }
HTML
<html>
<head>
<title>Elevation Service</title>
<link rel="stylesheet" type="text/css" href="./style.css" />
<script type="module" src="./index.js"></script>
<script>
// prettier-ignore
(g=>{var h,a,k,p="The Google Maps JavaScript API",c="google",l="importLibrary",q="__ib__",m=document,b=window;b=b[c]||(b[c]={});var d=b.maps||(b.maps={}),r=new Set,e=new URLSearchParams,u=()=>h||(h=new Promise(async(f,n)=>{await (a=m.createElement("script"));e.set("libraries",[...r]+"");for(k in g)e.set(k.replace(/[A-Z]/g,t=>"_"+t[0].toLowerCase()),g[k]);e.set("callback",c+".maps."+q);a.src=`https://maps.${c}apis.com/maps/api/js?`+e;d[q]=f;a.onerror=()=>h=n(Error(p+" could not load."));a.nonce=m.querySelector("script[nonce]")?.nonce||"";m.head.append(a)}));d[l]?console.warn(p+" only loads once. Ignoring:",g):d[l]=(f,...n)=>r.add(f)&&u().then(()=>d[l](f,...n))})({
key: "GOOGLE_MAPS_API_KEY"
});
</script>
</head>
<body>
<gmp-map
center="63.333,-150.5"
zoom="8"
map-id="DEMO_MAP_ID"
map-type-id="terrain"></gmp-map>
</body>
</html>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 https://github.com/googlemaps-samples/js-api-samples.gitcd samples/elevation-simplenpm inpm start