Zoom MKMapView to fit polyline points

Question

I have an array, allCollections, that holds programmatically-created arrays of CLLocations the user has recorded through my iOS app. Each sub-array in allCollections holds a

Answer 1

-(void)zoomToPolyLine: (MKMapView*)map polyline: (MKPolyline*)polyline animated: (BOOL)animated
{
    [map setVisibleMapRect:[polyline boundingMapRect] edgePadding:UIEdgeInsetsMake(10.0, 10.0, 10.0, 10.0) animated:animated];
}

Answer 2

Swift 3 version of garafajon excellent code

    if let first = self.mapView.overlays.first {
        let rect = self.mapView.overlays.reduce(first.boundingMapRect, {MKMapRectUnion($0, $1.boundingMapRect)})
        self.mapView.setVisibleMapRect(rect, edgePadding: UIEdgeInsets(top: 50.0, left: 50.0, bottom: 50.0, right: 50.0), animated: true)
    }