Filter symbols by toggling a list | UNL Map JS Docs

Filter a set of symbols based on a property value in the data.
Note
If you want to test this example, edit it in JSFiddle or CodePen and replace the "YOUR-OWN-API-KEY" and "YOUR-OWN-VPM-ID" placeholders with your actual api key and vpm id.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Filter symbols by toggling a list</title>
<meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no" />
<script src="https://unpkg.com/unl-map-js@0.1.5/lib/unl-map-js.js"></script>
<link href="https://unpkg.com/unl-map-js@0.1.5/lib/unl-map-js.css" rel="stylesheet" />
<link
href="https://unpkg.com/maplibre-gl@2.1.9/dist/maplibre-gl.css"
rel="stylesheet"
/>
<style>
	body { margin: 0; padding: 0; }
	#map { position: absolute; top: 0; bottom: 0; width: 100%; }
</style>
</head>
<body>
<style>
.filter-group {
font: 12px/20px "Helvetica Neue", Arial, Helvetica, sans-serif;
font-weight: 600;
position: absolute;
top: 10px;
right: 10px;
z-index: 1;
border-radius: 3px;
width: 120px;
color: #fff;
}
 
.filter-group input[type="checkbox"]:first-child + label {
border-radius: 3px 3px 0 0;
}
 
.filter-group label:last-child {
border-radius: 0 0 3px 3px;
border: none;
}
 
.filter-group input[type="checkbox"] {
display: none;
}
 
.filter-group input[type="checkbox"] + label {
background-color: #3386c0;
display: block;
cursor: pointer;
padding: 10px;
border-bottom: 1px solid rgba(0, 0, 0, 0.25);
}
 
.filter-group input[type="checkbox"] + label {
background-color: #3386c0;
text-transform: capitalize;
}
 
.filter-group input[type="checkbox"] + label:hover,
.filter-group input[type="checkbox"]:checked + label {
background-color: #4ea0da;
}
 
.filter-group input[type="checkbox"]:checked + label:before {
content: "✔";
margin-right: 5px;
}
</style>
<div id="map"></div>
<nav id="filter-group" class="filter-group"></nav>
 
<script>
var places = {
type: "FeatureCollection",
features: [
{
type: "Feature",
properties: {
icon: "theatre",
},
geometry: {
type: "Point",
coordinates: [-77.038659, 38.931567],
},
},
{
type: "Feature",
properties: {
icon: "theatre",
},
geometry: {
type: "Point",
coordinates: [-77.003168, 38.894651],
},
},
{
type: "Feature",
properties: {
icon: "bar",
},
geometry: {
type: "Point",
coordinates: [-77.090372, 38.881189],
},
},
{
type: "Feature",
properties: {
icon: "bicycle",
},
geometry: {
type: "Point",
coordinates: [-77.052477, 38.943951],
},
},
{
type: "Feature",
properties: {
icon: "music",
},
geometry: {
type: "Point",
coordinates: [-77.031706, 38.914581],
},
},
{
type: "Feature",
properties: {
icon: "music",
},
geometry: {
type: "Point",
coordinates: [-77.020945, 38.878241],
},
},
{
type: "Feature",
properties: {
icon: "music",
},
geometry: {
type: "Point",
coordinates: [-77.007481, 38.876516],
},
},
],
};
 
var filterGroup = document.getElementById("filter-group");
var map = new UnlSdk.Map({
container: "map",
apiKey: "YOUR-OWN-API-KEY",
vpmId: "YOUR-OWN-VPM-ID",
center: [-77.04, 38.907],
zoom: 11.15,
});
 
map.on("load", function () {
// Add a GeoJSON source containing place coordinates and information.
map.addSource("places", {
type: "geojson",
data: places,
});
 
places.features.forEach(function (feature) {
var symbol = feature.properties["icon"];
var layerID = "poi-" + symbol;
 
// 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": symbol + "_15",
"icon-overlap": "always",
},
filter: ["==", "icon", symbol],
});
 
// Add checkbox and label elements for the layer.
var input = document.createElement("input");
input.type = "checkbox";
input.id = layerID;
input.checked = true;
filterGroup.appendChild(input);
 
var label = document.createElement("label");
label.setAttribute("for", layerID);
label.textContent = symbol;
filterGroup.appendChild(label);
 
// When the checkbox changes, update the visibility of the layer.
input.addEventListener("change", function (e) {
map.setLayoutProperty(
layerID,
"visibility",
e.target.checked ? "visible" : "none"
);
});
}
});
});
</script>
 
</body>
</html>