Can I use an ObservedObject inside a Coordinator? - swift

Question

I have a MapView using MKMapView, and I have a HomeView which shows the MapView and ResultsCarouselView (for now just replacing it with Circle for ease).
If I have an observable object to manage the state for this HomeView, is it possible to use this from the coordinator? For example, anything I call from HomeState in the coordinator does not update HomeView:
MapCoordinator
final class MapCoordinator: NSObject, MKMapViewDelegate {
#ObservedObject var homeState = HomeState()
// other code, init, etc.
func mapView(_ mapView: MKMapView, didUpdate userLocation: MKUserLocation) {
self.homeState.setUserLocated(true)
}
}
HomeState:
class HomeState: NSObject, ObservableObject {
#Published var userLocated = false
func setUserLocated(_ value: Bool) {
self.userLocated = value // debugger comes here, but is this another instance or something?
}
}
HomeView:
struct HomeView: View {
#ObservedObject var homeState = HomeState()
var body: some View {
ZStack(alignment: .bottom) {
MapView()
if (homeState.userLocated) {
Circle() // this doesn't show up
}
}
}
}

Answer 1

struct MapView: UIViewRepresentable {
#StateObject var homeState = HomeState()
func makeUIView(context: Context) -> MKMapView {
let mapView = MKMapView()
mapView.delegate = context.coordinator
return mapView
}
func updateUIView(_ view: MKMapView, context: Context) {
}
func makeCoordinator() -> Coordinator {
Coordinator(self)
}
class Coordinator: NSObject, MKMapViewDelegate {
var parent: MapView
init(_ parent: MapView) {
self.parent = parent
}
func mapView(_ mapView: MKMapView, didUpdate userLocation: MKUserLocation) {
self.parent.homeState.setUserLocated(true)
}
}
}
You use the parent variable in the Coordinator to modify any #State or #ObservableObject such as your HomeState #ObservedObject