This example creates a map with tappable markers displaying a secret message.
Read the documentation.
TypeScript
function initMap(): void { const map = new google.maps.Map( document.getElementById("map") as HTMLElement, { zoom: 4, center: { lat: -25.363882, lng: 131.044922 }, } ); const bounds: google.maps.LatLngBoundsLiteral = { north: -25.363882, south: -31.203405, east: 131.044922, west: 125.244141, }; // Display the area between the location southWest and northEast. map.fitBounds(bounds); // Add 5 markers to map at random locations. // For each of these markers, give them a title with their index, and when // they are clicked they should open an infowindow with text from a secret // message. const secretMessages = ["This", "is", "the", "secret", "message"]; const lngSpan = bounds.east - bounds.west; const latSpan = bounds.north - bounds.south; for (let i = 0; i < secretMessages.length; ++i) { const marker = new google.maps.Marker({ position: { lat: bounds.south + latSpan * Math.random(), lng: bounds.west + lngSpan * Math.random(), }, map: map, }); attachSecretMessage(marker, secretMessages[i]); } } // Attaches an info window to a marker with the provided message. When the // marker is clicked, the info window will open with the secret message. function attachSecretMessage( marker: google.maps.Marker, secretMessage: string ) { const infowindow = new google.maps.InfoWindow({ content: secretMessage, }); marker.addListener("click", () => { infowindow.open(marker.get("map"), marker); }); } declare global { interface Window { initMap: () => void; } } window.initMap = initMap;
JavaScript
function initMap() { const map = new google.maps.Map(document.getElementById("map"), { zoom: 4, center: { lat: -25.363882, lng: 131.044922 }, }); const bounds = { north: -25.363882, south: -31.203405, east: 131.044922, west: 125.244141, }; // Display the area between the location southWest and northEast. map.fitBounds(bounds); // Add 5 markers to map at random locations. // For each of these markers, give them a title with their index, and when // they are clicked they should open an infowindow with text from a secret // message. const secretMessages = ["This", "is", "the", "secret", "message"]; const lngSpan = bounds.east - bounds.west; const latSpan = bounds.north - bounds.south; for (let i = 0; i < secretMessages.length; ++i) { const marker = new google.maps.Marker({ position: { lat: bounds.south + latSpan * Math.random(), lng: bounds.west + lngSpan * Math.random(), }, map: map, }); attachSecretMessage(marker, secretMessages[i]); } } // Attaches an info window to a marker with the provided message. When the // marker is clicked, the info window will open with the secret message. function attachSecretMessage(marker, secretMessage) { const infowindow = new google.maps.InfoWindow({ content: secretMessage, }); marker.addListener("click", () => { infowindow.open(marker.get("map"), marker); }); } 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; }
HTML
<html> <head> <title>Using Closures in Event Listeners</title> <script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script> <link rel="stylesheet" type="text/css" href="./style.css" /> <script type="module" src="./index.js"></script> </head> <body> <div id="map"></div> <!-- The `defer` attribute causes the callback 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-event-closure 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