Get features under the mouse pointer

Use the queryRenderedFeatures function to display the attributes of map elements when they are hovered over.


npm install --save @maptiler/sdk

main.js

import { Map, MapStyle, config } 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: [-96, 37.8],
    zoom: 3
});

map.on('mousemove', function (e) {
    const features = map.queryRenderedFeatures(e.point);

    // Limit the number of properties we're displaying for
    // legibility and performance
    const displayProperties = [
        'type',
        'properties',
        'id',
        'layer',
        'source',
        'sourceLayer',
        'state'
    ];

    const displayFeatures = features.map(function (feat) {
        const displayFeat = {};
        displayProperties.forEach(function (prop) {
            displayFeat[prop] = feat[prop];
        });
        return displayFeat;
    });

    document.getElementById('features').innerHTML = JSON.stringify(
        displayFeatures,
        null,
        2
    );
});

index.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="robots" content="noindex">
  <title>Get features under the mouse pointer</title>
  <link rel="stylesheet" href="./style.css">
</head>
<body>
  <style>
  #features {
      position: absolute;
      top: 0;
      right: 0;
      bottom: 0;
      width: 50%;
      overflow: auto;
      background: rgba(255, 255, 255, 0.8);
  }
  #map canvas {
      cursor: crosshair;
  }
  </style>
  <div id="map"></div>
  <pre id="features"></pre>
  <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%;}

<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>Get features under the mouse pointer</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%;
    }

    #features {
      position: absolute;
      top: 0;
      right: 0;
      bottom: 0;
      width: 50%;
      overflow: auto;
      background: rgba(255, 255, 255, 0.8);
    }

    #map canvas {
      cursor: crosshair;
    }
  </style>
</head>

<body>
  <div id="map"></div>
  <pre id="features"></pre>
  <script>
    maptilersdk.config.apiKey = 'YOUR_MAPTILER_API_KEY_HERE';
    const map = new maptilersdk.Map({
      container: 'map',
      style: maptilersdk.MapStyle.STREETS,
      center: [-96, 37.8],
      zoom: 3
    });

    map.on('mousemove', function (e) {
      const features = map.queryRenderedFeatures(e.point);

      // Limit the number of properties we're displaying for
      // legibility and performance
      const displayProperties = [
        'type',
        'properties',
        'id',
        'layer',
        'source',
        'sourceLayer',
        'state'
      ];

      const displayFeatures = features.map(function (feat) {
        const displayFeat = {};
        displayProperties.forEach(function (prop) {
          displayFeat[prop] = feat[prop];
        });
        return displayFeat;
      });

      document.getElementById('features').innerHTML = JSON.stringify(
        displayFeatures,
        null,
        2
      );
    });
  </script>
</body>

</html>