Show polygon information on click

When a user clicks on a polygon, a Popup will appear displaying additional details. This feature allows you to show the attributes of the selected element.


npm install --save @maptiler/sdk

main.js

import { Map, MapStyle, config, Popup } from '@maptiler/sdk';
import '@maptiler/sdk/dist/maptiler-sdk.css';

config.apiKey = 'YOUR_MAPTILER_API_KEY_HERE';
const map = new Map({
    container: 'map',
    style: MapStyle.STREETS, 
    center: [-100.04, 38.907],
    zoom: 3
});

map.on('load', function () {
    // Add a source for the state polygons.
    map.addSource('states', {
        'type': 'geojson',
        'data':
            'https://d2ad6b4ur7yvpq.cloudfront.net/naturalearth-3.3.0/ne_110m_admin_1_states_provinces_shp.geojson'
    });

    // Add a layer showing the state polygons.
    map.addLayer({
        'id': 'states-layer',
        'type': 'fill',
        'source': 'states',
        'paint': {
            'fill-color': 'rgba(200, 100, 240, 0.4)',
            'fill-outline-color': 'rgba(200, 100, 240, 1)'
        }
    });

    // When a click event occurs on a feature in the states layer, open a popup at the
    // location of the click, with description HTML from its properties.
    map.on('click', 'states-layer', function (e) {
        new Popup()
            .setLngLat(e.lngLat)
            .setHTML(e.features[0].properties.name)
            .addTo(map);
    });

    // Change the cursor to a pointer when the mouse is over the states layer.
    map.on('mouseenter', 'states-layer', function () {
        map.getCanvas().style.cursor = 'pointer';
    });

    // Change it back to a pointer when it leaves.
    map.on('mouseleave', 'states-layer', function () {
        map.getCanvas().style.cursor = '';
    });
});

index.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="robots" content="noindex">
  <title>Show polygon information on click</title>
  <link rel="stylesheet" href="./style.css">
</head>
<body>
  <div id="map"></div>
  <script type="module" src="./main.js"></script>
</body>
</html>

style.css

body {margin: 0; padding: 0;}
#map {position: absolute; top: 0; bottom: 0; width: 100%;}
.maplibregl-popup {
  max-width: 400px;
  font: 12px/20px 'Helvetica Neue', Arial, Helvetica, sans-serif;
}

<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Show polygon information on click</title>
<script src="https://cdn.maptiler.com/maptiler-sdk-js/v4.1.0/maptiler-sdk.umd.min.js"></script>
<link href="https://cdn.maptiler.com/maptiler-sdk-js/v4.1.0/maptiler-sdk.css" rel="stylesheet" />
<style>
  body {margin: 0; padding: 0;}
  #map {position: absolute; top: 0; bottom: 0; width: 100%;}
  .maplibregl-popup {
    max-width: 400px;
    font: 12px/20px 'Helvetica Neue', Arial, Helvetica, sans-serif;
  }
</style>
</head>
<body>
<div id="map"></div>
<script>
    maptilersdk.config.apiKey = 'YOUR_MAPTILER_API_KEY_HERE';
    const map = new maptilersdk.Map({
        container: 'map',
        style: maptilersdk.MapStyle.STREETS, 
        center: [-100.04, 38.907],
        zoom: 3
    });

    map.on('load', function () {
        // Add a source for the state polygons.
        map.addSource('states', {
            'type': 'geojson',
            'data':
                'https://d2ad6b4ur7yvpq.cloudfront.net/naturalearth-3.3.0/ne_110m_admin_1_states_provinces_shp.geojson'
        });

        // Add a layer showing the state polygons.
        map.addLayer({
            'id': 'states-layer',
            'type': 'fill',
            'source': 'states',
            'paint': {
                'fill-color': 'rgba(200, 100, 240, 0.4)',
                'fill-outline-color': 'rgba(200, 100, 240, 1)'
            }
        });

        // When a click event occurs on a feature in the states layer, open a popup at the
        // location of the click, with description HTML from its properties.
        map.on('click', 'states-layer', function (e) {
            new maptilersdk.Popup()
                .setLngLat(e.lngLat)
                .setHTML(e.features[0].properties.name)
                .addTo(map);
        });

        // Change the cursor to a pointer when the mouse is over the states layer.
        map.on('mouseenter', 'states-layer', function () {
            map.getCanvas().style.cursor = 'pointer';
        });

        // Change it back to a pointer when it leaves.
        map.on('mouseleave', 'states-layer', function () {
            map.getCanvas().style.cursor = '';
        });
    });
</script>
</body>
</html>