boundaries-simple

Sample code supporting Google Maps Platform JavaScript API documentation. author(s): Geo Developer IX Documentation Team

HTML

<!doctype html>
<!--
 @license
 Copyright 2025 Google LLC. All Rights Reserved.
 SPDX-License-Identifier: Apache-2.0
-->

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

    <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))})({
            });
    </script>
  </head>
  <body>
    <gmp-map
      center="20.773,-156.01"
      zoom="12"
      map-id="8b37d7206ccf0121d4414bb0"></gmp-map>
  </body>
</html>

CSS

/**
 * @license
 * Copyright 2025 Google LLC. All Rights Reserved.
 * SPDX-License-Identifier: Apache-2.0
 */

/* 
 * Always set the map height explicitly to define the size of the div element
 * that contains the map. 
 */
gmp-map {
  height: 100%;
}

/* 
 * Optional: Makes the sample page fill the window. 
 */
html,
body {
  height: 100%;
  margin: 0;
  padding: 0;
}

JavaScript

'use strict';
/**
 * @license
 * Copyright 2025 Google LLC. All Rights Reserved.
 * SPDX-License-Identifier: Apache-2.0
 */

/**
 * This is the simplest possible data-driven styling example.
 * It calls the styling function with a Place ID.
 */

let featureLayer;

async function init() {
  // Request needed libraries.
  await google.maps.importLibrary('maps');

  // Get the gmp-map element.
  const mapElement = document.querySelector('gmp-map');

  // Get the inner map.
  const innerMap = mapElement.innerMap;

  // Get the feature layer.
  featureLayer = innerMap.getFeatureLayer('LOCALITY');

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

  // Apply the style to a single boundary.
  featureLayer.style = (options) => {
    const feature = options.feature;
    if (feature.placeId === 'ChIJ0zQtYiWsVHkRk8lRoB1RNPo') {
      // Hana, HI
      return featureStyleOptions;
    }
    return null;
  };
}

void init();