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
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')
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).