Style polygon data features with color

This example shows an approach to styling polygon geometry based data features.

Read the documentation.

TypeScript

const mapElement = document.querySelector('gmp-map')!;
let innerMap: google.maps.Map;
const setStyle: google.maps.FeatureStyleFunction = (params) => {
    const datasetFeature = params.feature as google.maps.DatasetFeature;
    // 'typecategory' is an attribute in this Dataset.
    const typeCategory = datasetFeature.datasetAttributes.typecategory;

    switch (typeCategory) {
        case 'Undeveloped': // Color undeveloped areas blue.
            return {
                strokeColor: 'blue',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'blue',
                fillOpacity: 0.3,
            };
            break;
        case 'Parkway': // Color historical house sites red.
            return {
                strokeColor: 'red',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'red',
                fillOpacity: 0.5,
            };
            break;
        default: // Color other type categories green.
            return {
                strokeColor: 'green',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'green',
                fillOpacity: 0.3,
            };
            break;
    }
};

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

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

    // Dataset ID for NYC park data.
    const datasetId = 'a75dd002-ad20-4fe6-af60-27cd2ed636b4';
    const datasetLayer = innerMap.getDatasetFeatureLayer(datasetId);
    datasetLayer.style = setStyle;
}

void init();

JavaScript

const mapElement = document.querySelector('gmp-map');
let innerMap;
const setStyle = (params) => {
    const datasetFeature = params.feature;
    // 'typecategory' is an attribute in this Dataset.
    const typeCategory = datasetFeature.datasetAttributes.typecategory;

    switch (typeCategory) {
        case 'Undeveloped': // Color undeveloped areas blue.
            return {
                strokeColor: 'blue',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'blue',
                fillOpacity: 0.3,
            };
            break;
        case 'Parkway': // Color historical house sites red.
            return {
                strokeColor: 'red',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'red',
                fillOpacity: 0.5,
            };
            break;
        default: // Color other type categories green.
            return {
                strokeColor: 'green',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'green',
                fillOpacity: 0.3,
            };
            break;
    }
};

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

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

    // Dataset ID for NYC park data.
    const datasetId = 'a75dd002-ad20-4fe6-af60-27cd2ed636b4';
    const datasetLayer = innerMap.getDatasetFeatureLayer(datasetId);
    datasetLayer.style = setStyle;
}

void init();

CSS

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

#attribution {
    background-color: rgba(255, 255, 255, 0.7);
    font-family: 'Roboto', 'Arial', sans-serif;
    font-size: 10px;
    padding: 2px;
    margin: 2px;
}

HTML

<html>
    <head>
        <title>Style a polygon data feature with more detail</title>

        <link rel="stylesheet" type="text/css" href="./style.css" />
        <script type="module" src="./index.js"></script>
        <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))})({
                key: "AIzaSyA6myHzS10YXdcazAFalmXvDkrYCp5cLc8"
            });
        </script>
    </head>
    <body>
        <gmp-map
            center="40.580732, -74.152826"
            zoom="14"
            map-id="5cd2c9ca1cf05670">
            <div id="attribution" slot="control-block-end-inline-start">
                Data source: NYC Open Data
            </div>
        </gmp-map>
    </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 https://github.com/googlemaps-samples/js-api-samples.git
  cd samples/dds-datasets-polygon-colors
  npm i
  npm start