Mapbox GL JS Creating Custom Legend

Question

I have created a custom map in Mapbox Studio with a tileset to create a choropleth map I have then exported the map, to extend the map using Mapbox GL JS.

I have followed the tutorial for creating a legend, which works fine when using Javascipt.j: https://www.mapbox.com/mapbox.js/example/v1.0.0/custom-legend/

I need to use the Mapbox GL JS because I have also created popups with custom CSS which work quite nicely.

"map.legendControl.addLegend(document.getElementById('legend').innerHTML);" causes the map not to display the popups.

Please could someone offer assistance in getting a custom legend in Mapbox to work using Mapbox GL JS, as there is no documentation on the Mapbox website.

<!DOCTYPE html>
<html>
<head>
    <meta charset='utf-8' />
    <title>Show polygon information on click</title>
    <meta name='viewport' content='initial-scale=1,maximum-scale=1,user-scalable=no' />
    <script src='https://api.tiles.mapbox.com/mapbox-gl-js/v0.44.2/mapbox-gl.js'></script>
    <link href='https://api.tiles.mapbox.com/mapbox-gl-js/v0.44.2/mapbox-gl.css' rel='stylesheet' />

<style>
        body { margin:0; padding:0; }
        #map { position:absolute; top:0; bottom:0; width:100%; }
</style>
</head>

<body>

<style>
.legend label,
.legend span {
  display:block;
  float:left;
  height:15px;
  width:20%;
  text-align:center;
  font-size:9px;
  color:#808080;
   }
</style>


 <div id='legend'  style='display:none;'>
 <strong>Indices of Multiple Deprivation (IMD) Score </strong>
  <nav class='legend clearfix'>
    <span style='background:#FED976;'></span>
    <span style='background:#FD8D3C;'></span>
    <span style='background:#FC4E2A;'></span>
    <span style='background:#E31A1C;'></span>
    <span style='background:#BD0026;'></span>
    <label>0-19</label>
    <label>20-34</label>
    <label>35-49</label>
    <label>50-64</label>
    <label>65-82</label>
    <small>Source: <a href="https://data.cdrc.ac.uk/dataset/cdrc-english-indices-of-deprivation-2015-geodata-pack-liverpool-e08000012">Consumer Data Research Centre</a></small>
 </div>

<div id='map'></div>
<script>

mapboxgl.accessToken = 'pk.eyJ1IjoidGFzdGF0aGFtMSIsImEiOiJjamZ1ejY2bmYxNHZnMnhxbjEydW9sM29hIn0.w9ndNH49d91aeyvxSjKQqg';

  var map = new mapboxgl.Map({
     container: 'map',
     style: 'mapbox://styles/tastatham1/cjg3vyld813id2spdnhy4sf9u',
     center: [-2.981979, 53.406315],
     zoom: 11,
     minZoom: 11,
    maxZoom: 15,
 });

   map.legendControl.addLegend(document.getElementById('legend').innerHTML);


</script>

</body>
</html>

AndrewHarvey AndrewHarvey · Accepted Answer · 2018-04-22T09:51:09

The example you've linked to is for Mapbox.js, which is different to Mapbox GL JS.

https://www.mapbox.com/mapbox-gl-js/example/updating-choropleth/ is an example of doing a basic legend with Mapbox GL JS.

Mapbox GL JS Creating Custom Legend

2 Answers