Add markers to a web map with a symbol layer | NMaps GL JS Docs

This example draws points from a GeoJSON collection to a map.

Upon loading, the map uses loadImage to add an image to the application, addSource to add a collection of points to the application, and then addLayer to draw the image on the map at each point location.

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Add markers to a web map with a symbol layer</title>
<meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no" />
<script src="https://cdn.ndrive.com/nmapsgl/v.1.6.8/nmaps-gl.js"></script>
<link href="https://cdn.ndrive.com/nmapsgl/v.1.6.8/nmaps-gl.css" rel="stylesheet" />
<style>
	body { margin: 0; padding: 0; }
	#map { position: absolute; top: 0; bottom: 0; width: 100%; }
</style>
</head>
<body>
<div id="map"></div>
<script>
	// TO MAKE THE MAP APPEAR YOU MUST ADD YOUR ACCESS TOKEN
	nmapsgl.accessToken = '<your access token here>';
	
const map = new nmapsgl.Map({
container: 'map',
style: 'Streets',
center: [-96, 37.8],
zoom: 3
});
 
map.on('load', () => {
// Add an image to use as a custom marker
map.loadImage(
'https://nmaps-gl.ndrive.com/nmaps-gl-js/assets/custom_marker.png',
(error, image) => {
if (error) throw error;
map.addImage('custom-marker', image);
// Add a GeoJSON source with 2 points
map.addSource('points', {
'type': 'geojson',
'data': {
'type': 'FeatureCollection',
'features': [
{
'type': 'Feature',
'geometry': {
'type': 'Point',
'coordinates': [
-77.03238901390978, 38.913188059745586
]
},
'properties': {
'title': 'NMaps DC'
}
},
{
// feature for NMaps SF
'type': 'Feature',
'geometry': {
'type': 'Point',
'coordinates': [-122.414, 37.776]
},
'properties': {
'title': 'NMaps SF'
}
}
]
}
});
 
// Add a symbol layer
map.addLayer({
'id': 'points',
'type': 'symbol',
'source': 'points',
'layout': {
'icon-image': 'custom-marker',
// get the title name from the source's "title" property
'text-field': ['get', 'title'],
'text-font': ['Open Sans Regular'],
'text-offset': [0, 1.25],
'text-anchor': 'top'
}
});
}
);
});
</script>
 
</body>
</html>