Filter symbols by text input | NMaps GL JS Docs

Filter symbols by icon name by typing in a text input.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Filter symbols by text input</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>
<style>
.filter-ctrl {
position: absolute;
top: 10px;
right: 10px;
z-index: 1;
}
 
.filter-ctrl input[type='text'] {
font: 12px/20px 'Helvetica Neue', Arial, Helvetica, sans-serif;
width: 100%;
border: 0;
background-color: #fff;
margin: 0;
color: rgba(0, 0, 0, 0.5);
padding: 10px;
box-shadow: 0 0 0 2px rgba(0, 0, 0, 0.1);
border-radius: 3px;
width: 180px;
}
</style>
<div id="map"></div>
<div class="filter-ctrl">
<input
id="filter-input"
type="text"
name="filter"
placeholder="Filter by name"
/>
</div>
 
<script>
	// TO MAKE THE MAP APPEAR YOU MUST ADD YOUR ACCESS TOKEN
	nmapsgl.accessToken = '<your access token here>';
	
const places = {
'type': 'FeatureCollection',
'features': [
{
'type': 'Feature',
'properties': {
'icon': 'T174',
'text': 'Theatre'
},
'geometry': {
'type': 'Point',
'coordinates': [-77.038659, 38.931567]
}
},
{
'type': 'Feature',
'properties': {
'icon': 'T174',
'text': 'Theatre'
},
'geometry': {
'type': 'Point',
'coordinates': [-77.003168, 38.894651]
}
},
{
'type': 'Feature',
'properties': {
'icon': 'T166',
'text': 'Bar'
},
'geometry': {
'type': 'Point',
'coordinates': [-77.090372, 38.881189]
}
},
{
'type': 'Feature',
'properties': {
'icon': 'T202',
'text': 'Metro'
},
'geometry': {
'type': 'Point',
'coordinates': [-77.052477, 38.943951]
}
},
{
'type': 'Feature',
'properties': {
'icon': 'T159',
'text': 'Cinema'
},
'geometry': {
'type': 'Point',
'coordinates': [-77.031706, 38.914581]
}
},
{
'type': 'Feature',
'properties': {
'icon': 'T159',
'text': 'Cinema'
},
'geometry': {
'type': 'Point',
'coordinates': [-77.020945, 38.878241]
}
},
{
'type': 'Feature',
'properties': {
'icon': 'T174',
'text': 'Cinema'
},
'geometry': {
'type': 'Point',
'coordinates': [-77.007481, 38.876516]
}
}
]
};
 
const layerIDs = []; // Will contain a list used to filter against.
const filterInput = document.getElementById('filter-input');
const map = new nmapsgl.Map({
container: 'map',
style: 'Light',
center: [-77.04, 38.907],
zoom: 11.15
});
 
map.on('load', () => {
// Add a GeoJSON source containing place coordinates and information.
map.addSource('places', {
'type': 'geojson',
'data': places
});
 
places.features.forEach((feature) => {
const symbol = feature.properties['icon'];
const text = feature.properties['text'];
const layerID = 'poi-' + text.toLowerCase();
 
// Add a layer for this symbol type if it hasn't been added already.
if (!map.getLayer(layerID)) {
map.addLayer({
'id': layerID,
'type': 'symbol',
'source': 'places',
'layout': {
'icon-image': 'poi-category-' + symbol,
'icon-allow-overlap': true,
'text-field': text,
'text-font': ['Open Sans Regular'],
'text-size': 11,
'text-transform': 'uppercase',
'text-letter-spacing': 0.05,
'text-offset': [0, 1.5]
},
'paint': {
'text-color': '#202',
'text-halo-color': '#fff',
'text-halo-width': 2
},
'filter': ['==', 'icon', symbol]
});
 
layerIDs.push(layerID);
}
});
 
filterInput.addEventListener('keyup', (e) => {
// If the input value matches a layerID set
// it's visibility to 'visible' or else hide it.
const value = e.target.value.trim().toLowerCase();
layerIDs.forEach((layerID) => {
map.setLayoutProperty(
layerID,
'visibility',
layerID.indexOf(value) > -1 ? 'visible' : 'none'
);
});
});
});
</script>
 
</body>
</html>