Removing Polyline for Google Map - ios

Question

I want to remove d polyline in google map , but it remain I have try everything as you can see from the code also I check the debug area and the rectangle.map is nil?? but it still appear on the map and I do not want to user the clear method is work correct but I have other element on the map that I dint want to remove
DispatchQueue.main.async {
let path = GMSMutablePath()
path.add(CLLocationCoordinate2D(latitude: 37.36, longitude: -122.0))
path.add(CLLocationCoordinate2D(latitude: 37.45, longitude: -122.0))
path.add(CLLocationCoordinate2D(latitude: 37.45, longitude: -122.2))
path.add(CLLocationCoordinate2D(latitude: 37.36, longitude: -122.2))
path.add(CLLocationCoordinate2D(latitude: 37.36, longitude: -122.0))
let rectangle = GMSPolyline(path: path)
var oldPolylineArr = [GMSPolyline]()
oldPolylineArr.append(rectangle)
if self.count == 0 {
rectangle.map = self.googelMap
print("count \(self.count)")
self.count = 1
}
else if self.count == 1 {
//rectangle.map = nil
//path.removeAllCoordinates()
self.count = 0
for p in (0 ..< oldPolylineArr.count) {
oldPolylineArr[p].map = nil
}
}
}
}

Answer 1

This is local variable ( Inside the function )
var oldPolylineArr = [GMSPolyline]()
oldPolylineArr.append(rectangle)
you need to make it an instance var , as it holds the last one , so get this line out
var oldPolylineArr = [GMSPolyline]()
Then to clear all do
oldPolylineArr.forEach { $0.map = nil }
after that set your new created polyline
rectangle.map = self.googelMap
This will add a polyline and remove the old
class ViewController:UIViewController {
var oldPolylineArr = [GMSPolyline]()
override func viewDidLoad() {
super.viewDidLoad()
}
func addPolyAndRemoveOld() {
DispatchQueue.main.async {
// remove here
oldPolylineArr.forEach { $0.map = nil }
// add new
let path = GMSMutablePath()
path.add(CLLocationCoordinate2D(latitude: 37.36, longitude: -122.0))
path.add(CLLocationCoordinate2D(latitude: 37.45, longitude: -122.0))
path.add(CLLocationCoordinate2D(latitude: 37.45, longitude: -122.2))
path.add(CLLocationCoordinate2D(latitude: 37.36, longitude: -122.2))
path.add(CLLocationCoordinate2D(latitude: 37.36, longitude: -122.0))
let rectangle = GMSPolyline(path: path)
oldPolylineArr.append(rectangle)
rectangle.map = self.googelMap
}
}
}