Style a boundary polygon

This example map demonstrates highlighting the boundary polygon for a single region.

Read the documentation.

TypeScript

let map: google.maps.Map;
//@ts-ignore
let featureLayer;

async function initMap() {
  // Request needed libraries.
  const { Map } = await google.maps.importLibrary("maps") as google.maps.MapsLibrary;

  map = new Map(document.getElementById('map') as HTMLElement, {
    center: { lat: 20.773, lng: -156.01 }, // Hana, HI
    zoom: 12,
    // In the cloud console, configure this Map ID with a style that enables the
    // "Locality" feature layer.
    mapId: 'a3efe1c035bad51b', // <YOUR_MAP_ID_HERE>,
  });

  //@ts-ignore
  featureLayer = map.getFeatureLayer('LOCALITY');

  // Define a style with purple fill and border.
  //@ts-ignore
  const featureStyleOptions: google.maps.FeatureStyleOptions = {
    strokeColor: '#810FCB',
    strokeOpacity: 1.0,
    strokeWeight: 3.0,
    fillColor: '#810FCB',
    fillOpacity: 0.5
  };

  // Apply the style to a single boundary.
  //@ts-ignore
  featureLayer.style = (options: { feature: { placeId: string; }; }) => {
    if (options.feature.placeId == 'ChIJ0zQtYiWsVHkRk8lRoB1RNPo') { // Hana, HI
      return featureStyleOptions;
    }
  };

}

initMap();
index.ts

JavaScript

let map;
//@ts-ignore
let featureLayer;

async function initMap() {
  // Request needed libraries.
  const { Map } = await google.maps.importLibrary("maps");

  map = new Map(document.getElementById("map"), {
    center: { lat: 20.773, lng: -156.01 }, // Hana, HI
    zoom: 12,
    // In the cloud console, configure this Map ID with a style that enables the
    // "Locality" feature layer.
    mapId: "a3efe1c035bad51b", // <YOUR_MAP_ID_HERE>,
  });
  //@ts-ignore
  featureLayer = map.getFeatureLayer("LOCALITY");

  // Define a style with purple fill and border.
  //@ts-ignore
  const featureStyleOptions = {
    strokeColor: "#810FCB",
    strokeOpacity: 1.0,
    strokeWeight: 3.0,
    fillColor: "#810FCB",
    fillOpacity: 0.5,
  };

  // Apply the style to a single boundary.
  //@ts-ignore
  featureLayer.style = (options) => {
    if (options.feature.placeId == "ChIJ0zQtYiWsVHkRk8lRoB1RNPo") {
      // Hana, HI
      return featureStyleOptions;
    }
  };
}

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;
}

style.css

HTML

<html>
  <head>
    <title>Boundaries Simple</title>

    <link rel="stylesheet" type="text/css" href="./style.css" />
    <script type="module" src="./index.js"></script>
  </head>
  <body>
    <div id="map"></div>

    <!-- 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: "AIzaSyB41DRUbKWJHPxaFjMAwdrzWzbVKartNGg", v: "weekly"});</script>
  </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 -b sample-boundaries-simple 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