Map layers and basemaps

Layers and base maps that make up the project summary map and project components map

Sources, Layers, and Source Types

The main layer source type in Moped is GeoJSON. The pattern for adding a source and layer to a react-map-gl map is to use the Source and Layer components. These two components are abstraction of Mapbox GL sources and layers. The Source component is responsible for the data and the Layer component is used to style the data of the source. An example of JSX for a vector tile layer is below.

<Source
  key={config.layerIdName}
  type="geojson"
  data={theGeojsonData}
>
  <Layer
    key={config.layerIdName}
    {...theOtherlayerProps}
  />
</Source>

GeoJSON layers

Layers that are created from user input (like selecting from the CTN segments or intersection layer or drawing lines or points) require a source with type geojson and, in Moped, the geojson is formatted as a GeoJSON feature collection.

The CTN segments and intersection points are also populated with GeoJSON data queried from AGOL feature servers called CTN segments FeatureServer and COA Intersection points FeatureServer.

Base Maps

Default basemap

In Moped, the default basemap style is Mapbox Light and the streets layer for the mapStyle prop in react-map-gl is mapbox://styles/mapbox/light-v10.

Aerial Imagery basemap

To add aerial imagery, a Nearmap layer is added as a raster tile set. Nearmap access and the API key is managed by CTM and can be inquired about through the COA ServiceNow Portal. The API key is stored in the DTS 1Password Developers vault and is titled Moped Nearmap API Key.

The aerial basemap is added by providing a raster tile configuration that uses the Nearmap API endpoint along with the API key to provide aerial tiles. A sample configuration is shown below. A Mapbox example of using a custom tile set is here. This configuration is passed to the mapStyle prop of a react-map-gl map much like the default streets basemap above. This time, an object is passed instead of the string source of a Mapbox style.

{
  sources: {
  "raster-tiles": {
      id: "aerial-tiles",
      type: "raster",
      tiles: [
        `https://api.nearmap.com/tiles/v3/Vert/{z}/{x}/{y}.jpg?apikey=${NEARMAP_KEY}`,
      ],
      tileSize: 256,
    },
  },
  layers: [
    {
      id: "aerial-tiles",
      type: "raster",
      source: "aerial-tiles",
      minzoom: 0,
      maxzoom: 22,
    },
  ],
}