ER map feature styles

EarthRanger styles spatial features using the SimpleStyle convention — a small JSON dictionary stored alongside each feature or feature type. The same dictionary surfaces in both the GeoJSON endpoints and the vector tile output, so a single style definition drives all clients.

Where the style lives

• SpatialFeatureType.presentation — JSONB column, the default styling for every feature of that type.

• SpatialFeature.presentation — JSONB column, optional per-feature override. Populated by importers (e.g. ArcGIS, GeoJSON upload) and the API; not editable through the admin.

• Resolution order: feature.presentation (if non-empty) → feature_type.presentation → {}. Exposed by the SpatialFeature.default_presentation property.

Supported keys

All keys follow the SimpleStyle convention — they’re feature properties, not Mapbox-style paint properties.

Key	Geometry	Type	Notes
stroke	line, polygon	hex color	Outline color.
stroke-width	line, polygon	number	Pixels.
stroke-opacity	line, polygon	0.0–1.0
fill	polygon	hex color	Polygon fill color. Canonical key (see below).
fill-opacity	polygon	0.0–1.0
fill-outline-color	polygon	hex color	Outline of the fill (Mapbox paint name; tolerated as a feature property for editor parity).
image	point	URL/path	Icon. Accepts absolute URL, /static/..., or data: URI.
width	point	number	Icon width in pixels.
height	point	number	Icon height in pixels.

Hex colors accept 3- or 6-digit form (#fff, #ffffff).

fill vs fill-color

fill is the SimpleStyle feature-property name. fill-color is the Mapbox style-spec paint property — it belongs on a style layer, not on a feature. Some legacy data (older hand-edits, non-standard imports) put fill-color on the feature. The codebase tolerates that:

• Read path: vector tiles expose both fill and fill-color as separate flat tile properties when present. GeoJSON endpoints flatten whichever key the JSON contains. Mapbox/MapLibre style layers should reference ["get", "fill"].

• Editor read: if a feature_type’s presentation has fill-color but no fill, the polygon-fill picker loads the legacy value so the user sees the actual stored color.

• Editor write: the editor only writes fill. When saving, fill-color is dropped if fill is set. Opening any legacy feature_type in the editor and saving normalizes its presentation forward.

Once stored data is fully migrated, the fill-color tolerance in vector_layers.SpatialFeatureLayer.presentation_keys can be removed.

How styles surface to clients

GeoJSON endpoints

FeatureGeoJsonView and FeatureSetGeoJsonView flatten the resolved presentation onto the feature’s properties. Clients see SimpleStyle keys at the top level — there is no nested presentation object:

{
  "type": "Feature",
  "properties": {
    "title": "...",
    "stroke": "#ffffff",
    "stroke-width": 3,
    "fill": "#555555",
    "fill-opacity": 0
  },
  "geometry": { ... }
}

The flattening is performed by the custom GeoJSON serializer in das/core/serializers.py.

Vector tiles (SpatialFeatureLayer)

Each supported key is emitted as its own flat tile property. Style layers reference them through expressions, e.g. for a fill layer:

{
  "type": "fill",
  "paint": {
    "fill-color": ["get", "fill"],
    "fill-opacity": ["get", "fill-opacity"]
  }
}

Note the asymmetry: the paint property is fill-color (Mapbox style-spec); the feature property it reads is fill (SimpleStyle).

Editing presentation

The SpatialFeatureType admin (/admin/mapping/spatialfeaturetype/) provides a per-geometry-type editor with color pickers, sliders, and live previews. The editor reads from and writes to the same presentation JSON column — there are no separate columns. An “Advanced” textarea exposes the raw JSON for power users; arbitrary keys placed there are preserved on save.

Per-feature overrides (SpatialFeature.presentation) are not editable in the admin and are typically populated by importers.

ArcGIS imports

ArcGIS imports derive a SimpleStyle-shaped dict from the source layer’s renderer and write it to SpatialFeatureType.presentation. See docs/topics/arcgis-features.md for the renderer mapping, the overwrite semantics, and the disable_import_feature_class_presentation flag for opting out.

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Style cookbook

Reference values for common feature types.

Boundaries

• National Park: {“fill”: “#555555”, “fill-opacity”: 0, “stroke”: “#00FFFF”, “stroke-opacity”: 0.7, “stroke-width”: 3}

• National Reserve: {“fill”: “#7CB74B”, “fill-opacity”: 0.2, “stroke”: “#4E633C”, “stroke-opacity”: 0.5, “stroke-width”: 2}

• Wildlife Reserve:

• Community Conservancy: {“fill”: “#555555”, “fill-opacity”: 0, “stroke”: “#FFC0CB”, “stroke-opacity”: 0.7, “stroke-width”: 3}

• Conservancy: {“fill”: “#00FF00”, “fill-opacity”: 0.1, “stroke”: “#87CEFA”, “stroke-opacity”: 0.7, “stroke-width”: 3}

• Conservation Area: {“fill”: “#FAD5C4”, “fill-opacity”: 0.2, “stroke”: “#FF5733”, “stroke-opacity”: 0.5, “stroke-width”: 2}

• Corridor: {“fill”: “#555555”, “fill-opacity”: 0.2, “stroke”: “#86b86e”, “stroke-opacity”: 0.7, “stroke-width”: 2}

• Patrol Block / Sector: {“fill”: “#555555”, “fill-opacity”: 0, “stroke”: “#87CEFA”, “stroke-opacity”: 0.7, “stroke-width”: 1}

• Forest Reserve: {“fill”: “#e4ffe2”, “fill-opacity”: 0.2, “stroke”: “#aee88d”, “stroke-opacity”: 0.5, “stroke-width”: 2}

• Forest Concession:

• Forest Conservation Area [ndoki]: {

• Wildlife Sanctuary: {“fill”: “#ffffc9”, “fill-opacity”: 0.2, “stroke”: “#efef4f”, “stroke-opacity”: 0.5, “stroke-width”: 2}

Roads

• Primary: {“stroke”: “#ffffff”, “stroke-opacity”: 0.5, “stroke-width”: 3}

• Secondary: {“stroke”: “#ffffff”, “stroke-opacity”: 0.5, “stroke-width”: 2}

• Tertiary: {“stroke”: “#ffffff”, “stroke-opacity”: 0.5, “stroke-width”: 1}

• Railway: {“stroke”: “#ffffff”, “stroke-opacity”: 0.5, “stroke-width”: 1}

Rivers

• Primary: {“stroke”: “#05e6ff”, “stroke-opacity”: 0.5, “stroke-width”: 3}

• Secondary: {“stroke”: “#05e6ff”, “stroke-opacity”: 0.5, “stroke-width”: 2}

• Tertiary: {“stroke”: “#05e6ff”, “stroke-opacity”: 0.5, “stroke-width”: 1}

POI

• Points of Interest [generic]: {“image”: “/static/feature-POI-star_flag.svg”}

• Bai_Forest Clearing: {“image”: “/static/bai-green.svg”}

• Fence Attendant House: {“image”: “/static/fence_attendant_house.svg”}

• Tourism Center: {“image”: “/static/tourism_center-black.svg”}

• Campsite: {“image”: “/static/campsite-olive.svg”}

• Hotel/Lodge: {“image”: “/static/lodging-black.svg”}

• Gate Post: {“image”: “/static/park_gate.svg”}

• Picnic/Rest Stop: {“image”: “/static/picnic_spot-black.svg”}

• Boma [lion]: {“image”: “/static/lion_sighting-med_green.svg”}

• Viewpoint: {“image”: “/static/viewpoint-black.svg”}

• Jetty: {“image”: “/static/jetty-black.svg”}

• Airstrip (point): {“image”: “/static/plane-gray.svg}

Operational

• Headquarters: {“image”: “/static/park_HQ-olive.svg”}

• Ranger Station: {“image”: “static/ranger_post-dk_olive.svg”}

• Ranger Post: {“image”: “static/ranger_post-dk_olive.svg”}

• Ranger Camp: {“image”: “/static/campsite-olive.svg”}

Fences

• Fencing_Unknown (generic): {“stroke”: “#ffaf01”, “stroke-opacity”: 0.8, “stroke-width”: 2}