Is it possible to get user location only the first time the component is mounted?

[Simplegram]

How do I get user location only the first time the component is mounted? I have a modal and I want to note the location at the time of opening the modal and display it on the map.

[KiwiKilian]

Did you try LocationManager.getLastKnownLocation() within a useEffect? I'm not sure, if this works without the UserLocation component beeing rendered, but it's worth a shot.

[KiwiKilian]

How does your code look now?

You could consider using another library like expo-location or @react-native-community/geolocation as these are made for imperatively getting the location.

[Simplegram]

So I have this function to update location of related states. I call this function on onFocusEffect and a button. When I setup a console.log to print out Lap, the latitude and longitude stays the same after pressing the button. The coordinate changes only when onFocusEffect is triggered (when opening the modal).

const updateLocation = () => {
  LocationManager.getLastKnownLocation()
    .then((lastKnownLocation) => {
        let lon: number = 0
        let lat: number = 0

        if (lastKnownLocation) {
            lon = lastKnownLocation.coords.longitude
            lat = lastKnownLocation.coords.latitude
        }

        setLap(prevLap => ({ ...prevLap, lon: lon, lat: lat }))
        setCenterCoordinate([lon, lat])
    })
}

I have looked into expo-location and I think it's more suitable than LocationManager for this purpose. Thanks for the suggestion.

Another question, does UserLocation's LocationManager stays active when it's unmounted (modal closed)? I suddenly have a battery draining/heat issue whenever my app is opened. When I remove/comment UserLocation component, my phone no longer heat up.

I also have another question related to map dark mode light mode switching for MapTiler. Should I create a new discussion?

[KiwiKilian]

I would also suggest, rather using expo-location for such use case. I can't say for sure, how the LocationManager behaves in that case.

Feel free to open another discussion, if it's another topic.

[dilaksh06]

@Simplegram and @KiwiKilian
Hi Simplegram, I'm happy to see you here! I'm a student currently working on a mobile app for a patrolling system. In this app, I need to continuously track the user's location as they move. The changing coordinates need to be collected and sent to the server in real-time.

I'm currently using the userLocation component for this purpose. It has a method called onUpdate, but it seems to provide the coordinates only once when the screen mounts. You can use this approach, mean while could you help me resolve this issue? I want to receive continuous location updates as the user moves.
kamalathasandilakshan@gmail.com
this is my email id, please give me a reply in email as well here also... I just need to complete this as soon as possible
Thank you!

[Simplegram]

I would also suggest, rather using expo-location for such use case. I can't say for sure, how the LocationManager behaves in that case.

Feel free to open another discussion, if it's another topic.

Okay then, thank you for your help.

[tyrauber]

Outside the map, use expo-location. 100%! No question. Do not try to use maplibre-react-native to extract user location.

The expo-task-manager integration in expo-location is optimized for foreground and background location tracking.

@dilaksh06 For long running location tracking in app foreground and background state use expo-location background task with foreground permissions.

[KiwiKilian]

To clarify, if you only need the coordinates while the <UserLocation /> component is rendered, I wouldn't add another lib/dependency to get the location. Then onUpdate should work fine for you. But if location is needed without rendering <UserLocation /> beeing rendered, I would go for another lib.