queryFeatureExtensions

fun queryFeatureExtensions(sourceIdentifier: String, feature: Feature, extension: String, extensionField: String, args: HashMap<String, Value>?, callback: QueryFeatureExtensionCallback)

Queries for feature extension values in a GeoJSON source.

Return

The result will be returned through the \link QueryFeatureExtensionCallback \endlink. The result could be a feature extension value containing either a value (expansion-zoom) or a feature collection (children or leaves). Or a string describing an error if the operation was not successful.

Parameters

sourceIdentifier

The identifier of the source to query.

feature

to look for in the query.

extension

, now only support keyword 'supercluster'.

extensionField

, now only support following three extensions: 'children': returns the children of a cluster (on the next zoom level). 'leaves': returns all the leaves of a cluster (given its cluster_id) 'expansion-zoom': returns the zoom on which the cluster expands into several children (useful for "click to zoom" feature).

args

used for further query specification when using 'leaves' extensionField. Now only support following two args: 'limit': the number of points to return from the query (must use type 'uint64_t', set to maximum for all points) 'offset': the amount of points to skip (for pagination, must use type 'uint64_t')