Filter symbols by toggling a list

Filter a set of symbols based on a property value in the data.


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 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]
            }
        }
    ]
};

const filterGroup = document.getElementById('filter-group');
const map = new Map({
    container: 'map',
    style: MapStyle.STREETS,
    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) {
        const symbol = feature.properties['icon'];
        const 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,
                    'icon-overlap': 'always'
                },
                'filter': ['==', 'icon', symbol]
            });

            // Add checkbox and label elements for the layer.
            const input = document.createElement('input');
            input.type = 'checkbox';
            input.id = layerID;
            input.checked = true;
            filterGroup.appendChild(input);

            const 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'
                );
            });
        }
    });
});

index.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="robots" content="noindex">
  <title>Filter symbols by toggling a list</title>
  <link rel="stylesheet" href="./style.css">
</head>
<body>
  <style>
  .filter-group {
      font: 12px/20px 'Helvetica Neue', Arial, Helvetica, sans-serif;
      font-weight: 600;
      position: absolute;
      top: 10px;
      left: 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 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>Filter symbols by toggling a list</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%;
    }

    .filter-group {
      font: 12px/20px 'Helvetica Neue', Arial, Helvetica, sans-serif;
      font-weight: 600;
      position: absolute;
      top: 10px;
      left: 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>
</head>

<body>
  <div id="map"></div>
  <nav id="filter-group" class="filter-group"></nav>
  <script>
    maptilersdk.config.apiKey = 'YOUR_MAPTILER_API_KEY_HERE';
    const 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]
          }
        }
      ]
    };

    const filterGroup = document.getElementById('filter-group');
    const map = new maptilersdk.Map({
      container: 'map',
      style: maptilersdk.MapStyle.STREETS,
      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) {
        const symbol = feature.properties['icon'];
        const 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,
              'icon-overlap': 'always'
            },
            'filter': ['==', 'icon', symbol]
          });

          // Add checkbox and label elements for the layer.
          const input = document.createElement('input');
          input.type = 'checkbox';
          input.id = layerID;
          input.checked = true;
          filterGroup.appendChild(input);

          const 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>