Mapbox iOS - Drawing line along with user location update - ios

Question

I am working on a project where I need to draw a line on map with each update of user location to show a full route where user has travelled.
I am currently using Mapbox iOS SDK (v4.0.2) for this. To achieve above goal I am using MGLPolyline to draw a line over map.
With the following code provided, I am facing an issue as some default shape automatically get drawn before the route gets started.
Following is the code which I have implemented in my project :
#interface ViewController () <MGLMapViewDelegate>
{
MGLPolyline *polyline;
}
#end
- (void)mapView:(MGLMapView *)mapView didUpdateUserLocation:(MGLUserLocation *)userLocation
{
CLLocationCoordinate2D coord[1];
coord[0] = userLocation.coordinate;
if (polyline)
{
[polyline appendCoordinates:coord count:sizeof(coord)];
}
else
{
polyline = [MGLPolyline polylineWithCoordinates:coord count:sizeof(coord)];
__weak typeof(self) weakSelf = self;
dispatch_async(dispatch_get_main_queue(), ^(void) {
[weakSelf.mapView addAnnotation:polyline];
});
}
}
- (CGFloat)mapView:(MGLMapView *)mapView alphaForShapeAnnotation:(MGLShape *)annotation
{
return 1.0f;
}
- (CGFloat)mapView:(MGLMapView *)mapView lineWidthForPolylineAnnotation:(MGLPolyline *)annotation
{
return 5.0f;
}
- (UIColor *)mapView:(MGLMapView *)mapView strokeColorForShapeAnnotation:(MGLShape *)annotation
{
return [UIColor redColor];
}

Answer 1

i've done similar project before with swift.
user selects two point on map for beginning and destination then we use a google service which takes two point and gives list of point for best route and i was using this method to draw a polyLine
i think you have two way to do this
1_using didupdate func of mapkit for saving all point that user moves then use the func i put below for drawing poly line
2_take the beginning and destination points then draw a polyline
func addPolyLineToMap(googlemaplist: [CLLocation?]){
var coordinates = googlemaplist.map({ (location: CLLocation!) -> CLLocationCoordinate2D in
return location.coordinate
})
print("locatios count")
print(googlemaplist.count)
var polyline = MKPolyline(coordinates: &coordinates, count: googlemaplist.count)
DispatchQueue.main.async {
self.MapKit.add(polyline)
}
}