Accept coordinates as input to a geocoder | Mapbox GL JS

This example uses the mapbox-gl-geocoder control to enable users to search for places using the Mapbox Geocoding API, and accept geographic coordinates in the search query.

Search for coordinates like -40, 170 to see the geocoder return a result.

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Accept coordinates as input to a geocoder</title>
<meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no">
<link href="https://api.mapbox.com/mapbox-gl-js/v2.14.1/mapbox-gl.css" rel="stylesheet">
<script src="https://api.mapbox.com/mapbox-gl-js/v2.14.1/mapbox-gl.js"></script>
<style>
body { margin: 0; padding: 0; }
#map { position: absolute; top: 0; bottom: 0; width: 100%; }
</style>
</head>
<body>
<script src="https://api.mapbox.com/mapbox-gl-js/plugins/mapbox-gl-geocoder/v5.0.0/mapbox-gl-geocoder.min.js"></script>
<link rel="stylesheet" href="https://api.mapbox.com/mapbox-gl-js/plugins/mapbox-gl-geocoder/v5.0.0/mapbox-gl-geocoder.css" type="text/css">
 
<div id="map"></div>
 
<script>
	// TO MAKE THE MAP APPEAR YOU MUST
	// ADD YOUR ACCESS TOKEN FROM
	// https://account.mapbox.com
	mapboxgl.accessToken = 'YOUR_MAPBOX_ACCESS_TOKEN';
const map = new mapboxgl.Map({
container: 'map',
// Choose from Mapbox's core styles, or make your own style with Mapbox Studio
style: 'mapbox://styles/mapbox/streets-v12',
center: [-79.4512, 43.6568],
zoom: 8
});
 
/* Given a query in the form "lng, lat" or "lat, lng"
* returns the matching geographic coordinate(s)
* as search results in carmen geojson format,
* https://github.com/mapbox/carmen/blob/master/carmen-geojson.md */
const coordinatesGeocoder = function (query) {
// Match anything which looks like
// decimal degrees coordinate pair.
const matches = query.match(
/^[ ]*(?:Lat: )?(-?\d+\.?\d*)[, ]+(?:Lng: )?(-?\d+\.?\d*)[ ]*$/i
);
if (!matches) {
return null;
}
 
function coordinateFeature(lng, lat) {
return {
center: [lng, lat],
geometry: {
type: 'Point',
coordinates: [lng, lat]
},
place_name: 'Lat: ' + lat + ' Lng: ' + lng,
place_type: ['coordinate'],
properties: {},
type: 'Feature'
};
}
 
const coord1 = Number(matches[1]);
const coord2 = Number(matches[2]);
const geocodes = [];
 
if (coord1 < -90 || coord1 > 90) {
// must be lng, lat
geocodes.push(coordinateFeature(coord1, coord2));
}
 
if (coord2 < -90 || coord2 > 90) {
// must be lat, lng
geocodes.push(coordinateFeature(coord2, coord1));
}
 
if (geocodes.length === 0) {
// else could be either lng, lat or lat, lng
geocodes.push(coordinateFeature(coord1, coord2));
geocodes.push(coordinateFeature(coord2, coord1));
}
 
return geocodes;
};
 
// Add the control to the map.
map.addControl(
new MapboxGeocoder({
accessToken: mapboxgl.accessToken,
localGeocoder: coordinatesGeocoder,
zoom: 4,
placeholder: 'Try: -40, 170',
mapboxgl: mapboxgl,
reverseGeocode: true
})
);
</script>
 
</body>
</html>