Help Needed – Refreshing a MapLibre Map Every Minute (Kotlin - KMP)

[Swamp2k9]

Hi everyone,

I’m just starting out with Kotlin and MapLibre and I’m having trouble getting my map to refresh automatically every minute. Below is the code I currently have for creating the map:

fun App() {
    MaplibreMap(
        baseStyle = BaseStyle.Uri("https://tiles.openfreemap.org/styles/liberty")
    ) {
        val amtrakRoutes = rememberGeoJsonSource(
            GeoJsonData.Uri("https://testpage.com/file/test.geojson")
        )
        CircleLayer(
            id = "amtrak-stations",
            source = amtrakRoutes,
            color = const(Color.Blue),
            opacity = const(1.5f)
        )
    }
}

I read in the Using a GeoJSON Source guide that I can use the setGeoJson() method to update the source, but I’m not sure where to call this method or how to obtain a reference to the MapLibreMap (or its Style) from within my composable.

Any guidance or sample code that shows how to:

1. Capture the native MapLibreMap/Style instance, and
2. Periodically (every 60 seconds) fetch a new GeoJSON file and apply it with setGeoJson()

would be greatly appreciated.

[sargunv]

You're reading the MapLibre Android documentation but using the MapLibre Compose library. The API is quite different.

Updating data in a map composition works just like updating anything in Compose UI; create some State containing your GeoJson data, and use the value from that state in rememberGeoJsonSource. When the state updates, so will the source.