SwfitUI navigationBarItems calls location permission twice - swift

Question

I created a button under navigationBarItems, and this button opens a new sheet, and the new sheet will pop up a window to ask user locations. However, in the new sheet, CLLocationManager() has been called twice, and location permission pop up window will disappear in a few seconds. When you create a regular button, the location pop up windown will be stay there until you select one of the options, and CLLocationManager() will only be called one time.
Code
ConentView.swift
import SwiftUI
struct ContentView: View {
#State var show = false
#State var showEditPage = false
var body: some View {
NavigationView {
List {
Text("Text")
Button("Location button") {
print("Location button tapped")
self.show.toggle()
}.sheet(isPresented: $show) {
NewPage()
}
}
.navigationBarItems(
trailing:
VStack {
Button(action: {
print("BarItemButton tapped")
self.showEditPage.toggle()
}) {
//Top right icon
Text("BarItemButton")
}.sheet(isPresented: $showEditPage) {
//Open sheet page
NewPage()
}
}//End of trailing VStack
)
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
NewPage.swift
import SwiftUI
struct NewPage: View {
#ObservedObject var locationManager = LocationManager()
var body: some View {
Text("New Page")
}
}
struct NewPage_Previews: PreviewProvider {
static var previews: some View {
NewPage()
}
}
LocationManager.swift
import SwiftUI
import Foundation
import CoreLocation
import Combine
class LocationManager: NSObject, ObservableObject {
private let locationManager = CLLocationManager()
let objectWillChange = PassthroughSubject<Void, Never>()
override init() {
super.init()
self.locationManager.delegate = self
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest
self.locationManager.requestWhenInUseAuthorization()
self.locationManager.startUpdatingLocation()
print("In LocationManger.swift #initi, this is called")
}
#Published var locationStatus: CLAuthorizationStatus? {
willSet {
objectWillChange.send()
}
}
#Published var lastLocation: CLLocation? {
willSet { objectWillChange.send() }
}
}
extension LocationManager: CLLocationManagerDelegate {
func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
self.locationStatus = status
print("In LocationManger.swift #Func locationManager, Status is updaing")
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
guard let location = locations.last else { return }
self.lastLocation = location
print("Location is updating")
}
}
GitHub
You can feel free to download the project to try it on your laptop to see the issue:
Github Example Project
Screenshot

Answer 1

Here are changes of possible approach to make it work in your code:
1) Make LocationManager be only one
class LocationManager: NSObject, ObservableObject {
static var defaultManager: LocationManager = {
LocationManager()
}()
...
2) Use default manager instead of creating every time SwiftUI wants to create/copy view structure
struct NewPage: View {
#ObservedObject var locationManager = LocationManager.defaultManager
...