This example uses a data layer to dynamically display information about a KML feature object when under the mouse cursor.
Read the documentation.
TypeScript
let map: google.maps.Map; function initMap(): void { map = new google.maps.Map(document.getElementById("map") as HTMLElement, { 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((feature) => { return /** @type {google.maps.Data.StyleOptions} */ { fillColor: feature.getProperty("color") as string, strokeWeight: 1, }; }); // Set mouseover event for each feature. map.data.addListener("mouseover", (event) => { (document.getElementById("info-box") as HTMLElement).textContent = event.feature.getProperty("letter"); }); } declare global { interface Window { initMap: () => void; } } window.initMap = initMap;
JavaScript
let 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((feature) => { return /** @type {google.maps.Data.StyleOptions} */ { fillColor: feature.getProperty("color"), strokeWeight: 1, }; }); // Set mouseover event for each feature. map.data.addListener("mouseover", (event) => { document.getElementById("info-box").textContent = event.feature.getProperty("letter"); }); } window.initMap = initMap;
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
<html> <head> <title>Data Layer: Event Handling</title> <link rel="stylesheet" type="text/css" href="./style.css" /> <script type="module" src="./index.js"></script> </head> <body> <div id="map"></div> <div id="info-box">?</div> <!-- The `defer` attribute causes the script to execute after the full HTML document has been parsed. For non-blocking uses, avoiding race conditions, and consistent behavior across browsers, consider loading using Promises. See https://developers.google.com/maps/documentation/javascript/load-maps-js-api for more information. --> <script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyB41DRUbKWJHPxaFjMAwdrzWzbVKartNGg&callback=initMap&v=weekly" defer ></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-layer-data-event 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