Removing Polylines

  • This example demonstrates how to add and remove a polyline from a Google Map using JavaScript/TypeScript.

  • It provides UI controls (buttons) to trigger the addition and removal of the polyline.

  • The polyline is initialized with a predefined path and styling.

  • Users can interact with the controls to dynamically show or hide the polyline on the map.

  • The sample code includes HTML, CSS, and JavaScript/TypeScript components for implementation.

This example adds a UI control that allows the user to remove the polyline from the map.

Read the documentation.

TypeScript

// This example adds a UI control allowing users to remove the polyline
// from the map.

let flightPath: google.maps.Polyline;
const mapElement = document.querySelector('gmp-map') as google.maps.MapElement;
let innerMap;

async function initMap() {
    await google.maps.importLibrary('maps');
    innerMap = mapElement.innerMap;

    const flightPathCoordinates: google.maps.LatLngLiteral[] = [
        { lat: 37.772, lng: -122.214 },
        { lat: 21.291, lng: -157.821 },
        { lat: -18.142, lng: 178.431 },
        { lat: -27.467, lng: 153.027 },
    ];

    flightPath = new google.maps.Polyline({
        path: flightPathCoordinates,
        strokeColor: '#FF0000',
        strokeOpacity: 1.0,
        strokeWeight: 2,
    });

    // add event listener for click event
    document.getElementById('add-line')!.addEventListener('click', addLine);
    document
        .getElementById('remove-line')!
        .addEventListener('click', removeLine);

    // initialize with line
    addLine();
}

function addLine(): void {
    flightPath.setMap(innerMap);
}

function removeLine(): void {
    flightPath.setMap(null);
}

initMap();
index.ts

JavaScript

// This example adds a UI control allowing users to remove the polyline
// from the map.
let flightPath;
const mapElement = document.querySelector('gmp-map');
let innerMap;
async function initMap() {
    await google.maps.importLibrary('maps');
    innerMap = mapElement.innerMap;
    const flightPathCoordinates = [
        { lat: 37.772, lng: -122.214 },
        { lat: 21.291, lng: -157.821 },
        { lat: -18.142, lng: 178.431 },
        { lat: -27.467, lng: 153.027 },
    ];
    flightPath = new google.maps.Polyline({
        path: flightPathCoordinates,
        strokeColor: '#FF0000',
        strokeOpacity: 1.0,
        strokeWeight: 2,
    });
    // add event listener for click event
    document.getElementById('add-line').addEventListener('click', addLine);
    document
        .getElementById('remove-line')
        .addEventListener('click', removeLine);
    // initialize with line
    addLine();
}
function addLine() {
    flightPath.setMap(innerMap);
}
function removeLine() {
    flightPath.setMap(null);
}
initMap();
index.js

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;
}

#floating-panel {
  position: absolute;
  top: 10px;
  left: 25%;
  z-index: 5;
  background-color: #fff;
  padding: 5px;
  border: 1px solid #999;
  text-align: center;
  font-family: "Roboto", "sans-serif";
  line-height: 30px;
  padding-left: 10px;
}

style.css

HTML

<html>
    <head>
        <title>Removing Polylines</title>

        <link rel="stylesheet" type="text/css" href="./style.css" />
        <script type="module" src="./index.js"></script>
        <!-- prettier-ignore -->
        <script>(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: "AIzaSyA6myHzS10YXdcazAFalmXvDkrYCp5cLc8", v: "weekly"});</script>
    </head>
    <body>
        <gmp-map center="0, -180" zoom="3">
            <div id="floating-panel" slot="control-block-start-inline-center">
                <input id="remove-line" type="button" value="Remove line" />
                <input id="add-line" type="button" value="Restore line" />
            </div>
        </gmp-map>
    </body>
</html>
index.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 https://github.com/googlemaps-samples/js-api-samples.git
  cd samples/polyline-remove
  npm i
  npm start