Mapbox GL JS
API Reference
Examples
Plugins
Style Specification
Getting started (1)Display a mapStyles (11)Add an animated icon to the mapAdd a generated icon to the mapGenerate and add a missing icon to the mapAdd a stretchable image to the mapAdd a default markerAdd an icon to the mapDisplay a map with a custom styleRender world copiesDisplay a satellite mapChange a map's styleDisplay a mapLayers (40)Add a 3D modelDisplay buildings in 3DAdd an animated icon to the mapExtrude polygons for 3D indoor mappingAdd a generated icon to the mapGenerate and add a missing icon to the mapAdd a stretchable image to the mapAdd an icon to the mapAdjust a layer's opacityAnimate a lineAnimate a series of imagesAnimate a pointChange building color based on zoom levelChange the case of labelsDisplay HTML clusters with custom propertiesCreate and style clustersChange a layer's color with buttonsAdd a custom style layerStyle circles with a data-driven propertyStyle lines with a data-driven propertyDisplay and style rich text labelsAdd a pattern to a polygonAdd a new layer below labelsAdd a GeoJSON lineDraw GeoJSON pointsAdd a GeoJSON polygonCreate a heatmap layerAdd hillshadingAdd an imageDisplay line that crosses 180th meridianCreate a gradient line using an expressionAdd multiple geometries from one GeoJSON sourceStyle ocean depth dataShow and hide layersChange worldview of administrative boundariesUpdate a choropleth layer by zoom levelVariable label placementAdd a videoVisualize population densityUse a fallback imageSources (16)Animate a lineAnimate a series of imagesAnimate a pointAdd a canvas sourceJoin local JSON data with vector tile geometriesAdd hillshadingAdd an imageDisplay line that crosses 180th meridianAdd live realtime dataUpdate a feature in realtimeAdd a raster tile sourceAdd a third party vector tile sourceCreate a time sliderAdd a vector tile sourceAdd a videoAdd a WMS sourceUser interaction (27)Adjust a layer's opacityCustomize camera animationsCenter the map on a clicked symbolChange a layer's color with buttonsAnimate 3D buildings based on ambient soundsDisable map rotationCreate a draggable MarkerFilter features within map viewFilter symbols by text inputFilter symbols by toggling a listCreate a hover effectDisplay a non-interactive mapChange a map's languageMeasure distancesGet coordinates of the mouse pointerHighlight features containing similar dataSelect features around a clicked pointGet features under the mouse pointerRestrict map panning to an areaChange a map's styleCreate a time sliderToggle interactionsChange worldview of administrative boundariesUpdate a choropleth layer by zoom levelHighlight features within a bounding boxFit to the bounds of a LineStringCreate a draggable pointCamera (13)Animate map camera around a pointAnimate a point along a routeCustomize camera animationsCenter the map on a clicked symbolFit a map to a bounding boxSlowly fly to a locationFly to a locationNavigate the map with game-like controlsJump to a series of locationsOffset the vanishing point using paddingPlay map locations as a slideshowFly to a location based on scroll positionSet pitch and bearingControls and overlays (17)Animate a markerChange the default position for attributionAdd custom icons with MarkersDisable scroll zoomView a fullscreen mapLocate the userSwipe between mapsDisplay driving directionsShow drawn polygon areaAdd a geocoderAdd a marker using a place nameDisplay map navigation controlsShow polygon information on clickDisplay a popup on clickDisplay a popup on hoverDisplay a popupAttach a popup to a marker instanceGeocoder (10)Supplement forward geocoding search results from another data sourceAccept coordinates as input to a geocoderUse a custom render function with a geocoderLimit geocoder results to a named regionUse the geocoder without a mapPlace the geocoder input outside the mapUse a custom camera animation with a geocoderLocalize the geocoder to a given languageAdd a geocoderSet a point after Geocoder resultBrowser support (1)Check if Mapbox GL JS is supportedInternationalization support (2)Use locally generated ideographsAdd support for right-to-left scripts

Show drawn polygon area

Use mapbox-gl-draw to draw a polygon and Turf.js to calculate its area in square meters.

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Show drawn polygon area</title>
<meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no" />
<script src="https://api.mapbox.com/mapbox-gl-js/v1.12.0/mapbox-gl.js"></script>
<link href="https://api.mapbox.com/mapbox-gl-js/v1.12.0/mapbox-gl.css" rel="stylesheet" />
<style>
	body { margin: 0; padding: 0; }
	#map { position: absolute; top: 0; bottom: 0; width: 100%; }
</style>
</head>
<body>
<style>
.calculation-box {
height: 75px;
width: 150px;
position: absolute;
bottom: 40px;
left: 10px;
background-color: rgba(255, 255, 255, 0.9);
padding: 15px;
text-align: center;
}
 
p {
font-family: 'Open Sans';
margin: 0;
font-size: 13px;
}
</style>
 
<script src="https://api.tiles.mapbox.com/mapbox.js/plugins/turf/v3.0.11/turf.min.js"></script>
<script src="https://api.mapbox.com/mapbox-gl-js/plugins/mapbox-gl-draw/v1.2.0/mapbox-gl-draw.js"></script>
<link
rel="stylesheet"
href="https://api.mapbox.com/mapbox-gl-js/plugins/mapbox-gl-draw/v1.2.0/mapbox-gl-draw.css"
type="text/css"
/>
<div id="map"></div>
<div class="calculation-box">
<p>Draw a polygon using the draw tools.</p>
<div id="calculated-area"></div>
</div>
 
<script>
	// TO MAKE THE MAP APPEAR YOU MUST
	// ADD YOUR ACCESS TOKEN FROM
	// https://account.mapbox.com
	mapboxgl.accessToken = '<your access token here>';
var map = new mapboxgl.Map({
container: 'map', // container id
style: 'mapbox://styles/mapbox/satellite-v9', //hosted style id
center: [-91.874, 42.76], // starting position
zoom: 12 // starting zoom
});
 
var draw = new MapboxDraw({
displayControlsDefault: false,
controls: {
polygon: true,
trash: true
}
});
map.addControl(draw);
 
map.on('draw.create', updateArea);
map.on('draw.delete', updateArea);
map.on('draw.update', updateArea);
 
function updateArea(e) {
var data = draw.getAll();
var answer = document.getElementById('calculated-area');
if (data.features.length > 0) {
var area = turf.area(data);
// restrict to area to 2 decimal points
var rounded_area = Math.round(area * 100) / 100;
answer.innerHTML =
'<p><strong>' +
rounded_area +
'</strong></p><p>square meters</p>';
} else {
answer.innerHTML = '';
if (e.type !== 'draw.delete')
alert('Use the draw tools to draw a polygon!');
}
}
</script>
 
</body>
</html>
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