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') as google.maps.MapElement;
let innerMap;
function setStyle(/* FeatureStyleFunctionOptions */ 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 /* FeatureStyleOptions */ {
                strokeColor: 'blue',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'blue',
                fillOpacity: 0.3,
            };
            break;
        case 'Parkway': // Color historical house sites red.
            return /* FeatureStyleOptions */ {
                strokeColor: 'red',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'red',
                fillOpacity: 0.5,
            };
            break;
        default: // Color other type categories green.
            return /* FeatureStyleOptions */ {
                strokeColor: 'green',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'green',
                fillOpacity: 0.3,
            };
            break;
    }
}

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

    // 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;
}

initMap();
index.ts

JavaScript

const mapElement = document.querySelector('gmp-map');
let innerMap;
function setStyle(/* FeatureStyleFunctionOptions */ 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 /* FeatureStyleOptions */ {
                strokeColor: 'blue',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'blue',
                fillOpacity: 0.3,
            };
            break;
        case 'Parkway': // Color historical house sites red.
            return /* FeatureStyleOptions */ {
                strokeColor: 'red',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'red',
                fillOpacity: 0.5,
            };
            break;
        default: // Color other type categories green.
            return /* FeatureStyleOptions */ {
                strokeColor: 'green',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'green',
                fillOpacity: 0.3,
            };
            break;
    }
}
async function initMap() {
    // 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;
}
initMap();
index.js

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;
}

style.css

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>
    <!-- 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="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>
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/dds-datasets-polygon-colors
  npm i
  npm start