Select platform: [Android](https://developers.google.com/maps/documentation/android-sdk/dds-datasets/style-data-features.md.txt "View this page for the Android platform docs.") [iOS](https://developers.google.com/maps/documentation/ios-sdk/dds-datasets/style-data-features.md.txt "View this page for the iOS platform docs.") [JavaScript](https://developers.google.com/maps/documentation/javascript/dds-datasets/style-data-features.md.txt "View this page for the JavaScript platform docs.")

<br />

Apply style to data features by setting the `style` property on a dataset
feature layer to a `google.maps.FeatureStyleFunction`, which can contain styling
logic, or a `google.maps.FeatureStyleOptions`, to uniformly style all features
for a layer. You can apply styles to data features for fill (color, opacity),
stroke (color, opacity, stroke weight), and diameter (points). This page shows
how to programmatically access a dataset and style its features, and walks
through styling examples for data features based on point, polygon, and polyline
geometries.

Data-driven styling for datasets renders data features based on the provided latitude
and longitude coordinates from the geospatial data file used to create the
dataset.

## Data feature attributes

All data in a dataset can be accessed in the feature style function. To get data
feature attributes, first get the dataset feature, which contains all data
within the dataset, then get the specific data attribute you want, as shown
here:


### TypeScript

```typescript
// Get the dataset feature, so we can work with all of its attributes.
const datasetFeature = params.feature as google.maps.DatasetFeature;
// Get all of the needed dataset attributes.
const furColors =
    datasetFeature.datasetAttributes.CombinationofPrimaryandHighlightColor;
```

### JavaScript

```javascript
// Get the dataset feature, so we can work with all of its attributes.
const datasetFeature = params.feature;
// Get all of the needed dataset attributes.
const furColors =
    datasetFeature.datasetAttributes.CombinationofPrimaryandHighlightColor;
```

<br />

## Feature style options

[Feature style options](https://developers.google.com/maps/documentation/javascript/reference/data-driven-styling.md.txt#FeatureStyleOptions)
are where you define styling for a data [feature layer](https://developers.google.com/maps/documentation/javascript/reference/data-driven-styling.md.txt#FeatureLayer),
for example styling the fill and stroke for polygons, or the color and diameter
of points. The following example shows feature style options, which could be
directly applied using the `style` property for a feature:


### TypeScript

```typescript
// Apply style to all features.
datasetLayer.style = { strokeColor: 'green', strokeWeight: 4 };
```

### JavaScript

```javascript
// Apply style to all features.
datasetLayer.style = { strokeColor: 'green', strokeWeight: 4 };
```

<br />

## The feature style function

Use a feature style function to define logic for styling dataset features.
To style a feature, set the `style` property to a `google.maps.FeatureStyleFunction`.
The style function is where where you define logic to style individual features
on a feature layer. When `featureLayer.style` is set, the style function is run
over every feature in the affected feature layer. The function is applied at the
time you set the style property. To update it, you must set the style property
again. The following example shows a simple feature style function:


### TypeScript

```typescript
const styleDefault = {
    strokeColor: 'green',
    strokeWeight: 2.0,
    strokeOpacity: 1.0,
    fillColor: 'green',
    fillOpacity: 0.3,
};

const styleClicked = {
    ...styleDefault,
    strokeColor: 'blue',
    fillColor: 'blue',
    fillOpacity: 0.5,
};

const styleMouseMove = {
    ...styleDefault,
    strokeWeight: 4.0,
};

function applyStyle(params: google.maps.FeatureStyleFunctionOptions) {
    const datasetFeature = params.feature;

    // Note, 'globalid' is an attribute in this dataset.
    if (
        lastClickedFeatureIds.includes(
            (datasetFeature as google.maps.DatasetFeature).datasetAttributes
                .globalid
        )
    ) {
        return styleClicked;
    }

    if (
        lastInteractedFeatureIds.includes(
            (datasetFeature as google.maps.DatasetFeature).datasetAttributes
                .globalid
        )
    ) {
        return styleMouseMove;
    }
    return styleDefault;
}
```

### JavaScript

```javascript
const styleDefault = {
    strokeColor: 'green',
    strokeWeight: 2.0,
    strokeOpacity: 1.0,
    fillColor: 'green',
    fillOpacity: 0.3,
};

const styleClicked = {
    ...styleDefault,
    strokeColor: 'blue',
    fillColor: 'blue',
    fillOpacity: 0.5,
};

const styleMouseMove = {
    ...styleDefault,
    strokeWeight: 4.0,
};

function applyStyle(params) {
    const datasetFeature = params.feature;

    // Note, 'globalid' is an attribute in this dataset.
    if (
        lastClickedFeatureIds.includes(
            datasetFeature.datasetAttributes.globalid
        )
    ) {
        return styleClicked;
    }

    if (
        lastInteractedFeatureIds.includes(
            datasetFeature.datasetAttributes.globalid
        )
    ) {
        return styleMouseMove;
    }
    return styleDefault;
}
```

<br />

The style function should always return consistent results when it is applied
over features. For example, if you wanted to randomly color a set of features,
the random part should not take place in the feature style function, as that
would cause unintended results. Because this function runs over every feature in
a layer, optimization is important. To avoid impacting rendering times, set
style to `null` when a layer is no longer in use.

## Point data styling example

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


<iframe src="https://maps-docs-team.web.app/samples/dds-datasets-point/dist/" allow="fullscreen; fullscreen"></iframe>

### About the dataset

The dataset used in this example is the result of a [2018 survey of squirrels](https://data.cityofnewyork.us/Environment/2018-Squirrel-Census-Fur-Color-Map/fak5-wcft) in Central Park, New York City.
In the following excerpt from the CSV data file, we see that columns `x` and `y`
are used for geography; a `LatLng` column is included, but it's not used in this
example since geographic position must be represented by two columns. The
squirrel census dataset contains a nice variety of different data points
relating to the observed fur color and behavior of squirrels (be sure to scroll
horizontally to see it all).

| X | Y | UniqueSquirrelID | Hectare | Shift | Date | Hectare SquirrelNumber | Age | PrimaryFurColor | HighlightFurColor | CombinationofPrimaryandHighlightColor | Colornotes | Location | AboveGroundSighter Measurement | SpecificLocation | Running | Chasing | Climbing | Eating | Foraging | Other Activities | Kuks | Quaas | Moans | Tailflags | Tailtwitches | Approaches | Indifferent | Runsfrom | OtherInteractions | LatLng |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| -73.9561344937861 | 40.7940823884086 | 37F-PM-1014-03 | 37F | PM | 10142018 | 3 |   |   |   | + |   |   |   |   | false | false | false | false | false |   | false | false | false | false | false | false | false | false |   | POINT (-73.9561344937861 40.7940823884086) |
| -73.9688574691102 | 40.7837825208444 | 21B-AM-1019-04 | 21B | AM | 10192018 | 4 |   |   |   | + |   |   |   |   | false | false | false | false | false |   | false | false | false | false | false | false | false | false |   | POINT (-73.9688574691102 40.7837825208444) |
| -73.9742811484852 | 40.775533619083 | 11B-PM-1014-08 | 11B | PM | 10142018 | 8 |   | Gray |   | Gray+ |   | Above Ground | 10 |   | false | true | false | false | false |   | false | false | false | false | false | false | false | false |   | POINT (-73.97428114848522 40.775533619083) |
| -73.9596413903948 | 40.7903128889029 | 32E-PM-1017-14 | 32E | PM | 10172018 | 14 | Adult | Gray |   | Gray+ | Nothing selected as Primary. Gray selected as Highlights. Made executive adjustments. |   |   |   | false | false | false | true | true |   | false | false | false | false | false | false | false | true |   | POINT (-73.9596413903948 40.7903128889029) |
| -73.9702676472613 | 40.7762126854894 | 13E-AM-1017-05 | 13E | AM | 10172018 | 5 | Adult | Gray | Cinnamon | Gray+Cinnamon |   | Above Ground |   | on tree stump | false | false | false | false | true |   | false | false | false | false | false | false | false | false |   | POINT (-73.9702676472613 40.7762126854894) |
| -73.9683613516225 | 40.7725908847499 | 11H-AM-1010-03 | 11H | AM | 10102018 | 3 | Adult | Cinnamon | White | Cinnamon+White |   |   |   |   | false | false | false | false | true |   | false | false | false | false | true | false | true | false |   | POINT (-73.9683613516225 40.7725908847499) |
| -73.9541201789795 | 40.7931811701082 | 36H-AM-1010-02 | 36H | AM | 10102018 | 2 | Adult | Gray |   | Gray+ | just outside hectare | Ground Plane | FALSE |   | false | false | false | false | true |   | false | false | false | false | false | false | false | false |   | POINT (-73.9541201789795 40.7931811701082) |

### Style point data features

The code in this example takes the simple approach of styling the fill color and
stroke color for each point based on the `CombinationofPrimaryandHighlightColor`
attribute, which combines the primary and secondary fur colors for each
squirrel.


### TypeScript

```typescript
function setStyle(params: { feature: google.maps.Feature }) {
    // Get the dataset feature, so we can work with all of its attributes.
    const datasetFeature = params.feature as google.maps.DatasetFeature;
    // Get all of the needed dataset attributes.
    const furColors =
        datasetFeature.datasetAttributes.CombinationofPrimaryandHighlightColor;

    // Apply styles. Fill is primary fur color, stroke is secondary fur color.
    switch (furColors) {
        case 'Black+':
            return {
                fillColor: 'black',
                pointRadius: 8,
            };
            break;
        case 'Cinnamon+':
            return {
                fillColor: '#8b0000',
                pointRadius: 8,
            };
            break;
        case 'Cinnamon+Gray':
            return {
                fillColor: '#8b0000',
                strokeColor: 'gray',
                pointRadius: 6,
            };
            break;
        case 'Cinnamon+White':
            return {
                fillColor: '#8b0000',
                strokeColor: 'white',
                pointRadius: 6,
            };
            break;
        case 'Gray+':
            return {
                fillColor: 'gray',
                pointRadius: 8,
            };
            break;
        case 'Gray+Cinnamon':
            return {
                fillColor: 'gray',
                strokeColor: '#8b0000',
                pointRadius: 6,
            };
            break;
        case 'Gray+Cinnamon, White':
            return {
                fillColor: 'silver',
                strokeColor: '#8b0000',
                pointRadius: 6,
            };
            break;
        case 'Gray+White':
            return {
                fillColor: 'gray',
                strokeColor: 'white',
                pointRadius: 6,
            };
            break;
        default: // Color not defined.
            return {
                fillColor: 'yellow',
                pointRadius: 8,
            };
            break;
    }
}
```

### JavaScript

```javascript
function setStyle(params) {
    // Get the dataset feature, so we can work with all of its attributes.
    const datasetFeature = params.feature;
    // Get all of the needed dataset attributes.
    const furColors =
        datasetFeature.datasetAttributes.CombinationofPrimaryandHighlightColor;

    // Apply styles. Fill is primary fur color, stroke is secondary fur color.
    switch (furColors) {
        case 'Black+':
            return {
                fillColor: 'black',
                pointRadius: 8,
            };
            break;
        case 'Cinnamon+':
            return {
                fillColor: '#8b0000',
                pointRadius: 8,
            };
            break;
        case 'Cinnamon+Gray':
            return {
                fillColor: '#8b0000',
                strokeColor: 'gray',
                pointRadius: 6,
            };
            break;
        case 'Cinnamon+White':
            return {
                fillColor: '#8b0000',
                strokeColor: 'white',
                pointRadius: 6,
            };
            break;
        case 'Gray+':
            return {
                fillColor: 'gray',
                pointRadius: 8,
            };
            break;
        case 'Gray+Cinnamon':
            return {
                fillColor: 'gray',
                strokeColor: '#8b0000',
                pointRadius: 6,
            };
            break;
        case 'Gray+Cinnamon, White':
            return {
                fillColor: 'silver',
                strokeColor: '#8b0000',
                pointRadius: 6,
            };
            break;
        case 'Gray+White':
            return {
                fillColor: 'gray',
                strokeColor: 'white',
                pointRadius: 6,
            };
            break;
        default: // Color not defined.
            return {
                fillColor: 'yellow',
                pointRadius: 8,
            };
            break;
    }
}
```

<br />

### Complete example code

#### See the complete example source code

### TypeScript

```typescript
const mapElement = document.querySelector('gmp-map')!;
let innerMap: google.maps.Map;
function setStyle(params: { feature: google.maps.Feature }) {
    // Get the dataset feature, so we can work with all of its attributes.
    const datasetFeature = params.feature as google.maps.DatasetFeature;
    // Get all of the needed dataset attributes.
    const furColors =
        datasetFeature.datasetAttributes.CombinationofPrimaryandHighlightColor;

    // Apply styles. Fill is primary fur color, stroke is secondary fur color.
    switch (furColors) {
        case 'Black+':
            return {
                fillColor: 'black',
                pointRadius: 8,
            };
            break;
        case 'Cinnamon+':
            return {
                fillColor: '#8b0000',
                pointRadius: 8,
            };
            break;
        case 'Cinnamon+Gray':
            return {
                fillColor: '#8b0000',
                strokeColor: 'gray',
                pointRadius: 6,
            };
            break;
        case 'Cinnamon+White':
            return {
                fillColor: '#8b0000',
                strokeColor: 'white',
                pointRadius: 6,
            };
            break;
        case 'Gray+':
            return {
                fillColor: 'gray',
                pointRadius: 8,
            };
            break;
        case 'Gray+Cinnamon':
            return {
                fillColor: 'gray',
                strokeColor: '#8b0000',
                pointRadius: 6,
            };
            break;
        case 'Gray+Cinnamon, White':
            return {
                fillColor: 'silver',
                strokeColor: '#8b0000',
                pointRadius: 6,
            };
            break;
        case 'Gray+White':
            return {
                fillColor: 'gray',
                strokeColor: 'white',
                pointRadius: 6,
            };
            break;
        default: // Color not defined.
            return {
                fillColor: 'yellow',
                pointRadius: 8,
            };
            break;
    }
}

async function init() {
    // Request needed libraries.
    const [{ event }] = await Promise.all([
        google.maps.importLibrary('core'),
        google.maps.importLibrary('maps'),
    ]);

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

    event.addListenerOnce(innerMap, 'idle', () => {
        // Add the data legend.
        makeLegend();
    });

    // Dataset ID for squirrel dataset.
    const datasetId = 'a99635b0-5e73-4b2a-8ae3-cb40f4b7f47e';
    const datasetLayer = innerMap.getDatasetFeatureLayer(datasetId);
    datasetLayer.style = setStyle;
}

// Creates a legend for the map.
function makeLegend() {
    const colors = {
        black: ['black'],
        cinnamon: ['#8b0000'],
        'cinnamon + gray': ['#8b0000', 'gray'],
        'cinnamon + white': ['#8b0000', 'white'],
        gray: ['gray'],
        'gray + cinnamon': ['gray', '#8b0000'],
        'gray + cinnamon + white': ['silver', '#8b0000'],
        'gray + white': ['gray', 'white'],
        'no color data': ['yellow'],
    };

    const legend = document.getElementById('legend');
    legend!.id = 'legend';
    const title = document.createElement('div');
    title.innerText = 'Fur Colors';
    title.classList.add('title');
    legend!.appendChild(title);

    for (const color of Object.keys(colors) as Iterable<keyof typeof colors>) {
        const wrapper = document.createElement('div');
        wrapper.id = 'container';
        const box = document.createElement('div');
        box.style.backgroundColor = colors[color][0];
        if (colors[color][1]) {
            box.style.borderColor = colors[color][1];
        } else {
            box.style.borderColor = colors[color][0];
        }
        box.classList.add('box');
        const txt = document.createElement('div');
        txt.classList.add('legend');
        txt.innerText = color;
        wrapper.appendChild(box);
        wrapper.appendChild(txt);
        legend!.appendChild(wrapper);
    }
}

void init();
```

### JavaScript

```javascript
const mapElement = document.querySelector('gmp-map');
let innerMap;
function setStyle(params) {
    // Get the dataset feature, so we can work with all of its attributes.
    const datasetFeature = params.feature;
    // Get all of the needed dataset attributes.
    const furColors =
        datasetFeature.datasetAttributes.CombinationofPrimaryandHighlightColor;

    // Apply styles. Fill is primary fur color, stroke is secondary fur color.
    switch (furColors) {
        case 'Black+':
            return {
                fillColor: 'black',
                pointRadius: 8,
            };
            break;
        case 'Cinnamon+':
            return {
                fillColor: '#8b0000',
                pointRadius: 8,
            };
            break;
        case 'Cinnamon+Gray':
            return {
                fillColor: '#8b0000',
                strokeColor: 'gray',
                pointRadius: 6,
            };
            break;
        case 'Cinnamon+White':
            return {
                fillColor: '#8b0000',
                strokeColor: 'white',
                pointRadius: 6,
            };
            break;
        case 'Gray+':
            return {
                fillColor: 'gray',
                pointRadius: 8,
            };
            break;
        case 'Gray+Cinnamon':
            return {
                fillColor: 'gray',
                strokeColor: '#8b0000',
                pointRadius: 6,
            };
            break;
        case 'Gray+Cinnamon, White':
            return {
                fillColor: 'silver',
                strokeColor: '#8b0000',
                pointRadius: 6,
            };
            break;
        case 'Gray+White':
            return {
                fillColor: 'gray',
                strokeColor: 'white',
                pointRadius: 6,
            };
            break;
        default: // Color not defined.
            return {
                fillColor: 'yellow',
                pointRadius: 8,
            };
            break;
    }
}

async function init() {
    // Request needed libraries.
    const [{ event }] = await Promise.all([
        google.maps.importLibrary('core'),
        google.maps.importLibrary('maps'),
    ]);

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

    event.addListenerOnce(innerMap, 'idle', () => {
        // Add the data legend.
        makeLegend();
    });

    // Dataset ID for squirrel dataset.
    const datasetId = 'a99635b0-5e73-4b2a-8ae3-cb40f4b7f47e';
    const datasetLayer = innerMap.getDatasetFeatureLayer(datasetId);
    datasetLayer.style = setStyle;
}

// Creates a legend for the map.
function makeLegend() {
    const colors = {
        black: ['black'],
        cinnamon: ['#8b0000'],
        'cinnamon + gray': ['#8b0000', 'gray'],
        'cinnamon + white': ['#8b0000', 'white'],
        gray: ['gray'],
        'gray + cinnamon': ['gray', '#8b0000'],
        'gray + cinnamon + white': ['silver', '#8b0000'],
        'gray + white': ['gray', 'white'],
        'no color data': ['yellow'],
    };

    const legend = document.getElementById('legend');
    legend.id = 'legend';
    const title = document.createElement('div');
    title.innerText = 'Fur Colors';
    title.classList.add('title');
    legend.appendChild(title);

    for (const color of Object.keys(colors)) {
        const wrapper = document.createElement('div');
        wrapper.id = 'container';
        const box = document.createElement('div');
        box.style.backgroundColor = colors[color][0];
        if (colors[color][1]) {
            box.style.borderColor = colors[color][1];
        } else {
            box.style.borderColor = colors[color][0];
        }
        box.classList.add('box');
        const txt = document.createElement('div');
        txt.classList.add('legend');
        txt.innerText = color;
        wrapper.appendChild(box);
        wrapper.appendChild(txt);
        legend.appendChild(wrapper);
    }
}

void init();
```

### CSS

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

#attributionLabel {
    background-color: rgba(255, 255, 255, 0.8);
    font-family: 'Roboto', 'Arial', sans-serif;
    font-size: 10px;
    padding: 2px;
    margin: 2px;
}

#legend,
#dataset,
#counter {
    background-color: #e5e5e5;
    width: 15em;

    margin-left: 1em;
    border-radius: 8px;
    font-family: Roboto, sans-serif;
    overflow: hidden;
}

#dataset select {
    border-radius: 0;
    padding: 0.1em;
    border: 1px solid black;
    width: auto;
    margin: 0.5em 1em;
}

.title {
    padding: 0.5em 1em;
    font-weight: bold;
    font-size: 1.5em;
    margin-bottom: 0.5em;
    background-color: rgb(66, 133, 244);
    color: white;
    width: 100%;
}

.button {
    font-size: 1.2em;
    margin: 1em;
    background-color: rgb(66, 133, 244);
    color: white;
    padding: 0.5em;
    border-radius: 8px;
}

#legend #container {
    margin: 0.5em;
    display: flex;
}

#legend div .box {
    display: flex;
    width: 1em;
    height: 1em;
    border-radius: 50%;
    border: 2px solid;
}

#legend div .legend {
    display: flex;
    padding: 0.3em;
}
```

### HTML

```html
<html>
    <head>
        <title>Style a point data feature</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: "GOOGLE_MAPS_API_KEY"
            });
        </script>
    </head>
    <body>
        <gmp-map
            map-id="5cd2c9ca1cf05670"
            center="40.780101, -73.967780"
            zoom="17"
            map-type-control="false"
            street-view-control="false"
            fullscreen-control="false">
            <div id="legend" slot="control-inline-start-block-start"></div>
            <div id="attributionLabel" slot="control-block-end-inline-start">
                Data source: NYC Open Data
            </div>
        </gmp-map>
    </body>
</html>
```

### Try Sample

[JSFiddle.net](https://jsfiddle.net/gh/get/library/pure/googlemaps-samples/js-api-samples/tree/main/dist/samples/dds-datasets-point/jsfiddle)

## Polygon data styling example

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


<iframe src="https://maps-docs-team.web.app/samples/dds-datasets-polygon-colors/dist/" allow="fullscreen; fullscreen"></iframe>

### About the dataset

The dataset used in this example depicts [parks in New York City](https://data.cityofnewyork.us/Recreation/Parks-Properties/enfh-gkve).
The following excerpt from the dataset GeoJSON file shows a representative
feature entry.

```json
{
  "type": "Feature",
  "properties": {
    "jurisdiction": "DPR",
    "mapped": "False",
    "zipcode": "11356",
    "acres": "0.05",
    "location": "College Pl., College Pt. Blvd., bet. 11 Ave. and 12 Ave.",
    "nys_assembly": "27",
    "councildistrict": "19",
    "url": "http://www.nycgovparks.org/parks/Q042/",
    "typecategory": "Triangle/Plaza",
    "us_congress": "14",
    "eapply": "Poppenhusen Park",
    "parentid": "Q-07",
    "gispropnum": "Q042",
    "retired": "false",
    "communityboard": "407",
    "objectid": "6248",
    "globalid": "F4810079-CBB9-4BE7-BBFA-B3C0C35D5DE5",
    "name311": "Poppenhusen Park",
    "department": "Q-07",
    "pip_ratable": "true",
    "subcategory": "Sitting Area/Triangle/Mall",
    "precinct": "109",
    "permit": "true",
    "acquisitiondate": null,
    "omppropid": "Q042",
    "gisobjid": "100000301",
    "signname": "Poppenhusen Park",
    "address": null,
    "permitparent": "Q-07",
    "class": "PARK",
    "nys_senate": "11",
    "permitdistrict": "Q-07",
    "borough": "Q",
    "waterfront": "false"
  },
  "geometry": {
    "type": "MultiPolygon",
    "coordinates": [
      [
        [
          [
            -73.84575702371716,
            40.78796240884273
          ],
          [
            -73.84593393292693,
            40.78796857347548
          ],
          [
            -73.84577256469657,
            40.787651355629556
          ],
          [
            -73.84575702371716,
            40.78796240884273
          ]
        ]
      ]
    ]
  }
},
```

### Style polygon data features

The code in this example applies special coloring to data features associated
with a `typecategory` of "Undeveloped" or "Parkway", and colors all other
features green.


### TypeScript

```typescript
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;
    }
};
```

### JavaScript

```javascript
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;
    }
};
```

<br />

### Complete example code

#### See the complete example source code

### TypeScript

```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

```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

```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
<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: "GOOGLE_MAPS_API_KEY"
            });
        </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

[JSFiddle.net](https://jsfiddle.net/gh/get/library/pure/googlemaps-samples/js-api-samples/tree/main/dist/samples/dds-datasets-polygon-colors/jsfiddle)

## Polyline data styling example

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


<iframe src="https://maps-docs-team.web.app/samples/dds-datasets-polyline/dist/" allow="fullscreen; fullscreen"></iframe>

### About the dataset

The dataset used in this example shows [bridges in the Seattle area](https://data-seattlecitygis.opendata.arcgis.com/datasets/9db5967e01224efcafbfbb64b06ff68f_0/explore).
The following excerpt from the dataset GeoJSON file shows a representative
feature entry.

```json
{
  "type": "Feature",
  "properties": {
      "OBJECTID": 1,
      "COMPTYPE": 66,
      "COMPKEY": 515774,
      "HANSEGKEY": 489781,
      "UNITID": "BRG-935",
      "UNITTYPE": " ",
      "BRGUNITID": "BRG-935",
      "UNITDESC_BRG": "YALE AVE BR REV LANE OC                                                                                                                                                                                                                                        ",
      "UNITDESC_SEG": "HOWELL ST ON RP BETWEEN HOWELL ST AND I5 SB                                                                                                                                                                                                                    ",
      "INSTDATE": null,
      "EXPDATE": null,
      "STATUS": " ",
      "STATUSDT": null,
      "CONDITION": " ",
      "CONDDT": null,
      "OWN": " ",
      "LSTVERIFY": null,
      "MAINTBY": " ",
      "ADDBY": "GARCIAA",
      "ADDDTTM": "2010-01-21T00:00:00Z",
      "MODBY": null,
      "MODDTTM": null,
      "BR_NBR": 935,
      "BR_CODE": " 935",
      "BR_TYPE": "ST",
      "BR_NAME": "YALE AVE BR REV LANE OC",
      "BR_FACILITIES": "YALE AVE-SR 5 ON RAMP",
      "BR_FEATURES": "SR 5 REV LANE",
      "BR_RATING": 0,
      "BR_INSET": 1,
      "BR_GEO": "DT",
      "BR_OWNER": "DOT",
      "BR_OWNER_NAME": "State of Washington",
      "GEOBASID": 0,
      "XGEOBASID": 0,
      "GISSEGKEY": 489781,
      "EARTHQUAKE_RESPONSE_TEAM": " ",
      "SHAPE_Length": 220.11891836147655
  },
  "geometry": {
      "type": "LineString",
      "coordinates": [
          [
              -122.329201929090928,
              47.616910448708538
          ],
          [
              -122.329206483407461,
              47.616976719821004
          ],
          [
              -122.32921802149356,
              47.617042137515213
          ],
          [
              -122.329236413912909,
              47.617105967923777
          ],
          [
              -122.329261454336034,
              47.617167494985758
          ],
          [
              -122.329292861855023,
              47.617226028479571
          ],
          [
              -122.329330284134699,
              47.617280911766009
          ],
          [
              -122.329373301365223,
              47.617331529154569
          ],
          [
              -122.329421430971635,
              47.617377312810319
          ],
          [
              -122.329474133027375,
              47.617417749124023
          ],
          [
              -122.32953081631139,
              47.617452384473893
          ]
      ]
  }
},
```

### Style polyline data features

The following snippet applies the same style to directly to all data features.
Since no logic is required, a feature style function is not used in this case.


### TypeScript

```typescript
// Apply style to all features.
datasetLayer.style = { strokeColor: 'green', strokeWeight: 4 };
```

### JavaScript

```javascript
// Apply style to all features.
datasetLayer.style = { strokeColor: 'green', strokeWeight: 4 };
```

<br />

#### See the complete example source code

### TypeScript

```typescript
const mapElement = document.querySelector('gmp-map')!;
let innerMap: google.maps.Map;
async function init() {
    // Request needed libraries.
    await google.maps.importLibrary('maps');

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

    // Dataset ID for Seattle Bridges
    const datasetId = '2438ee30-5366-4e84-82b7-a0d4dd1893fa';
    const datasetLayer = innerMap.getDatasetFeatureLayer(datasetId);

    // Apply style to all features.
    datasetLayer.style = { strokeColor: 'green', strokeWeight: 4 };
}

void init();
```

### JavaScript

```javascript
const mapElement = document.querySelector('gmp-map');
let innerMap;
async function init() {
    // Request needed libraries.
    await google.maps.importLibrary('maps');

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

    // Dataset ID for Seattle Bridges
    const datasetId = '2438ee30-5366-4e84-82b7-a0d4dd1893fa';
    const datasetLayer = innerMap.getDatasetFeatureLayer(datasetId);

    // Apply style to all features.
    datasetLayer.style = { strokeColor: 'green', strokeWeight: 4 };
}

void init();
```

### CSS

```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
<html>
    <head>
        <title>Style a polyline data feature</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: "GOOGLE_MAPS_API_KEY"
            });
        </script>
    </head>
    <body>
        <gmp-map
            center="47.59, -122.31"
            zoom="14"
            map-id="5cd2c9ca1cf05670"
            map-type-control="false">
            <div id="attribution" slot="control-block-end-inline-start">
                Data source: NYC Open Data
            </div>
        </gmp-map>
    </body>
</html>
```

### Try Sample

[JSFiddle.net](https://jsfiddle.net/gh/get/library/pure/googlemaps-samples/js-api-samples/tree/main/dist/samples/dds-datasets-polyline/jsfiddle)