No NSSortDescriptor on distanceToLocation for CKQuery?

Question

With a CloudKit CKQuery you can filter on distance (see sample). But how can you sort on distance? Like location ASC. A sort descriptor on location returns an error: query.sortDescriptors = [NSSortDescriptor(key: "distanceToLocation", ascending: true)] :

  static func getNearbySpots(location : CLLocation, completionHandler: (spots : CKRecord[]) -> Void) {
        let predicate = NSPredicate(format: "distanceToLocation:fromLocation:(location, %@) < 10000", location)

        let queryOperation = CKQueryOperation(query: query)
        var results : CKRecord[] = []

        queryOperation.recordFetchedBlock = {
            results += $0
        }

        queryOperation.queryCompletionBlock = {
            if $1 {
                NSLog($1.description,[])
                abort()
            } else {
                completionHandler(spots: results)
            }
        }

        self.publicDB().addOperation(queryOperation)
    }

Answer 1

Ok, found it. There is a CKLocationSortDescriptor where you can specify the location.

 query.sortDescriptors = [CKLocationSortDescriptor(key: "location", relativeLocation: location)]