Introduction to visualization

You can style basemap layers, which are composed of vector tile data, and feature layers, which are composed of features, to help visualize the data in your application.

Basemap styles

A basemap style is a set of visual properties such as fill colors, viewing levels, and fonts that define how the visual elements in a vector tile basemap layer are displayed. There are two types of basemap styles: default and custom.

• Default styles: Styles provided by Esri such as ArcGIS:Streets, ArcGIS:Topographic, and ArcGIS:Nova.
• Custom styles: Styles you create and save as items using the ArcGIS Vector Tile Style Editor.

How to display a custom basemap style

1. Create a style with the ArcGIS Vector Tile Style Editor.
2. Go to the new basemap layer's item page and copy its item ID.
3. Reference the MapLibre JS and CSS libraries.
4. Set the item ID as the basemap enumeration.
5. Access the basemap layer.

Example

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<link href="https://unpkg.com/maplibre-gl@3.2.1/dist/maplibre-gl.css" rel="stylesheet" />
<script src="https://unpkg.com/maplibre-gl@3.2.1/dist/maplibre-gl.js"></script>
<script>
const apiKey = "YOUR_API_KEY";
const basemapEnum = "6976148c11bd497d8624206f9ee03e30";  // Item id for custom basemap layer style

const map = new maplibregl.Map({
  container: "map",
  style: `https://basemaps-api.arcgis.com/arcgis/rest/services/styles/${basemapEnum}?type=style&token=${apiKey}`,
  zoom: 12,
  center: [-118.805, 34.027]
});
</script>

Feature styles

A feature layer can be styled in MapLibre GL JS with a layer connected to a GeoJSON source. Layers can contain expressions which use attribute values to calculate values.

How to style a feature layer

1. Define the data type (GeoJSON) and set the feature service URL.
2. Add the layer to the map and define its id, type, source, and paint stylings.

Example

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<link href="https://unpkg.com/maplibre-gl@3.2.1/dist/maplibre-gl.css" rel="stylesheet" />
<script src="https://unpkg.com/maplibre-gl@3.2.1/dist/maplibre-gl.js"></script>
<script>
  map.addSource("trails", {
    type: "geojson",
    data: trailsLayerURL
  });
   map.addLayer({
    id: "trails-line",
    type: "line",
    source: "trails",
    paint: {
      "line-color": "hsl(291, 44%, 60%)",
      "line-width": ["interpolate", ["linear"], ["get", "ELEV_GAIN"], 0, 3, 2300, 7],
      "line-opacity": 0.75
    }
  });
</script>

Tutorials

Style a feature layer

Use data-driven styling to apply symbol colors and styles to feature layers.

Style vector tiles

Change the fill and outline of vector tiles based on their attributes.

Display a custom basemap style

Add a styled vector basemap layer to a map.