Cannot stop Updates with stopUpdatingLocation and stopRelativeAltitudeUpdates

Question

I am building a paragliding app for watchOS, that can display and log values like altitude, speed, glide ratio and so on.

So far I built the UI, integrated some settings and I am receiving pressure sensor data and gps location. To save battery life I included a "stop button" that triggers the locationManager.stopUpdatingLocation and CMAltimeter.stopRelativeAltitudeUpdates functions. But in the console I can see still location and altitude updates coming in.

I uploaded the code to https://github.com/LukeCrouch/iAlti/tree/main/iAlti%20WatchKit%20Extension . The interesting file is probably the ControlsView, here I declare and call the relevant functions.

    func stopLocation() {
        self.locationManager.stopUpdatingLocation()
    }

I appreciate every bit of help I can get, this is my first time writing an App! :)

Cheers Luke

Answer 1

The problem is this line:

@ObservedObject var locationManager = LocationManager()

Every time the ControlsView is regenerated, that line runs afresh. So the LocationManager is a different LocationManager. So you are telling a LocationManager's CLLocationManager to stop updating, but this is a different CLLocationManager from the one that started.

Instead, make this a singleton environment object so that your app has just one LocationManager with just one CLLocationManager. That way, each time you talk to it, you are talking to the same one.