Style lines with a data-driven property

Create a visualization with a data expression for line-color.


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: [-122.48383155304096, 37.82882682974591],
    zoom: 16
});

map.on('load', function () {
    map.addSource('lines', {
        'type': 'geojson',
        'data': {
            'type': 'FeatureCollection',
            'features': [
                {
                    'type': 'Feature',
                    'properties': {
                        'color': '#F7455D' // red
                    },
                    'geometry': {
                        'type': 'LineString',
                        'coordinates': [
                            [-122.4833858013153, 37.829607404976734],
                            [-122.4830961227417, 37.82932776098012],
                            [-122.4830746650696, 37.82932776098012],
                            [-122.48218417167662, 37.82889558180985],
                            [-122.48218417167662, 37.82890193740421],
                            [-122.48221099376678, 37.82868372835086],
                            [-122.4822163581848, 37.82868372835086],
                            [-122.48205006122589, 37.82801003030873]
                        ]
                    }
                },
                {
                    'type': 'Feature',
                    'properties': {
                        'color': '#33C9EB' // blue
                    },
                    'geometry': {
                        'type': 'LineString',
                        'coordinates': [
                            [-122.48393028974533, 37.829471820141016],
                            [-122.48395174741744, 37.82940826466351],
                            [-122.48395174741744, 37.829412501697064],
                            [-122.48423874378203, 37.829357420242125],
                            [-122.48422533273697, 37.829361657278575],
                            [-122.48459815979002, 37.8293425906126],
                            [-122.48458743095398, 37.8293447091313],
                            [-122.4847564101219, 37.82932776098012],
                            [-122.48474299907684, 37.829331998018276],
                            [-122.4849334359169, 37.829298101706186],
                            [-122.48492807149889, 37.82930022022615],
                            [-122.48509705066681, 37.82920488676767],
                            [-122.48509168624878, 37.82920912381288],
                            [-122.48520433902739, 37.82905870855876],
                            [-122.48519897460936, 37.82905870855876],
                            [-122.4854403734207, 37.828594749716714],
                            [-122.48543500900269, 37.82860534241688],
                            [-122.48571664094925, 37.82808206121068],
                            [-122.48570591211319, 37.82809689109353],
                            [-122.4858346581459, 37.82797189627337],
                            [-122.48582661151886, 37.82797825194729],
                            [-122.4859634041786, 37.82788503534145],
                            [-122.48595803976059, 37.82788927246246],
                            [-122.48605459928514, 37.82786596829394]
                        ]
                    }
                }
            ]
        }
    });
    map.addLayer({
        'id': 'lines',
        'type': 'line',
        'source': 'lines',
        'paint': {
            'line-width': 3,
            // Use a get expression (https://docs.maptiler.com/gl-style-specification/expressions/#get)
            // to set the line-color to a feature property value.
            'line-color': ['get', 'color']
        }
    });
});

index.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="robots" content="noindex">
  <title>Style lines with a data-driven property</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%;}

<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>Style lines with a data-driven property</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%;}
</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: [-122.48383155304096, 37.82882682974591],
        zoom: 16
    });

    map.on('load', function () {
        map.addSource('lines', {
            'type': 'geojson',
            'data': {
                'type': 'FeatureCollection',
                'features': [
                    {
                        'type': 'Feature',
                        'properties': {
                            'color': '#F7455D' // red
                        },
                        'geometry': {
                            'type': 'LineString',
                            'coordinates': [
                                [-122.4833858013153, 37.829607404976734],
                                [-122.4830961227417, 37.82932776098012],
                                [-122.4830746650696, 37.82932776098012],
                                [-122.48218417167662, 37.82889558180985],
                                [-122.48218417167662, 37.82890193740421],
                                [-122.48221099376678, 37.82868372835086],
                                [-122.4822163581848, 37.82868372835086],
                                [-122.48205006122589, 37.82801003030873]
                            ]
                        }
                    },
                    {
                        'type': 'Feature',
                        'properties': {
                            'color': '#33C9EB' // blue
                        },
                        'geometry': {
                            'type': 'LineString',
                            'coordinates': [
                                [-122.48393028974533, 37.829471820141016],
                                [-122.48395174741744, 37.82940826466351],
                                [-122.48395174741744, 37.829412501697064],
                                [-122.48423874378203, 37.829357420242125],
                                [-122.48422533273697, 37.829361657278575],
                                [-122.48459815979002, 37.8293425906126],
                                [-122.48458743095398, 37.8293447091313],
                                [-122.4847564101219, 37.82932776098012],
                                [-122.48474299907684, 37.829331998018276],
                                [-122.4849334359169, 37.829298101706186],
                                [-122.48492807149889, 37.82930022022615],
                                [-122.48509705066681, 37.82920488676767],
                                [-122.48509168624878, 37.82920912381288],
                                [-122.48520433902739, 37.82905870855876],
                                [-122.48519897460936, 37.82905870855876],
                                [-122.4854403734207, 37.828594749716714],
                                [-122.48543500900269, 37.82860534241688],
                                [-122.48571664094925, 37.82808206121068],
                                [-122.48570591211319, 37.82809689109353],
                                [-122.4858346581459, 37.82797189627337],
                                [-122.48582661151886, 37.82797825194729],
                                [-122.4859634041786, 37.82788503534145],
                                [-122.48595803976059, 37.82788927246246],
                                [-122.48605459928514, 37.82786596829394]
                            ]
                        }
                    }
                ]
            }
        });
        map.addLayer({
            'id': 'lines',
            'type': 'line',
            'source': 'lines',
            'paint': {
                'line-width': 3,
                // Use a get expression (https://docs.maptiler.com/gl-style-specification/expressions/#get)
                // to set the line-color to a feature property value.
                'line-color': ['get', 'color']
            }
        });
    });
</script>
</body>
</html>