query
Queries for feature extension values in a GeoJSON source.
Parameters
The `source identifier` of the source to query.
The `feature` to look for in the query.
The `extension`, now only support keyword 'supercluster'.
The `extension field`, now only support following 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).
The `args` parameter used for further query specification when using 'leaves' extensionField. Now only support following 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') The result will be returned through the `query featureExtension callback`. 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.