Style Primitives

The DingiFeature protocol is used to provide details about geographic features contained in an DingiShapeSource or DingiVectorTileSource object. Each concrete subclass of MGLShape in turn has a subclass that conforms to this protocol. A feature object associates a shape with an optional identifier and attributes.

You can add custom data to display on the map by creating feature objects and adding them to an DingiShapeSource using the -[DingiShapeSource initWithIdentifier:shape:options:] method or DingiShapeSource.shape property.

In addition to adding data to the map, you can also extract data from the map: -[DingiMapView visibleFeaturesAtPoint:] and related methods return feature objects that correspond to features in the source. This enables you to inspect the properties of features in vector tiles loaded by DingiVectorTileSource objects. You also reuse these feature objects as overlay annotations.

While it is possible to add DingiFeature-conforming objects to the map as annotations using -[DingiMapView addAnnotations:] and related methods, doing so has trade-offs:

• Features added as annotations will not have identifier or attributes properties when used with feature querying.

• Features added as annotations become interactive. Taps and selection can be handled in -[DingiMapViewDelegate mapView:didSelectAnnotation:].

An DingiPointFeature object associates a point shape with an optional identifier and attributes.

An DingiPolygonFeature object associates a polygon shape with an optional identifier and attributes.

An DingiPolylineFeature object associates a polyline shape with an optional identifier and attributes.

A polyline feature is known as a LineString feature in GeoJSON.

An DingiMultiPolygonFeature object associates a multipolygon shape with an optional identifier and attributes.

An DingiMultiPolylineFeature object associates a multipolyline shape with an optional identifier and attributes.

A multipolyline feature is known as a MultiLineString feature in GeoJSON.

An DingiPointCollectionFeature object associates a point collection with an optional identifier and attributes.

A point collection feature is known as a MultiPoint feature in GeoJSON.

An DingiShapeCollectionFeature object associates a shape collection with an optional identifier and attributes.

DingiShapeCollectionFeature is most commonly used to add multiple shapes to a single DingiShapeSource. Configure the appearance of an DingiSource’s shape collection collectively using an DingiSymbolStyleLayer object, or use multiple instances of DingiCircleStyleLayer, DingiFillStyleLayer, and DingiLineStyleLayer to configure the appearance of each kind of shape inside the collection.

A shape collection feature is known as a feature collection in GeoJSON.