Jetpack Compose - store internet connection state in view model - android-jetpack-compose

Question

I have the below code to check the live network connection state.
How can I call the function to start checking for this network connection state from the view model init function?
How can I also make it so if there is a change in internet connection state, it updates this in the view model?
interface ConnectivityObserver {
fun observe(): Flow<Status>
enum class Status {
Available,
Unavailable,
Losing,
Lost
}
}
class NetworkConnectivityObserver(private val context: Context) : ConnectivityObserver {
private val connectivityManager =
context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
override fun observe(): Flow<ConnectivityObserver.Status> {
return callbackFlow {
val callback = object : ConnectivityManager.NetworkCallback() {
override fun onAvailable(network: Network) {
super.onAvailable(network)
launch { send(ConnectivityObserver.Status.Available) }
}
override fun onLosing(network: Network, maxMsToLive: Int) {
super.onLosing(network, maxMsToLive)
launch { send(ConnectivityObserver.Status.Losing) }
}
override fun onLost(network: Network) {
super.onLost(network)
launch { send(ConnectivityObserver.Status.Lost) }
}
override fun onUnavailable() {
super.onUnavailable()
launch { send(ConnectivityObserver.Status.Unavailable) }
}
}
connectivityManager.registerDefaultNetworkCallback(callback)
awaitClose {
connectivityManager.unregisterNetworkCallback(callback)
}
}.distinctUntilChanged()
}
}
class NetworkStatusViewModel : ViewModel() {
var connectedToInternet: Boolean by mutableStateOf(false)
init {
connectedToInternet = checkNetworkConnection()
}
}
fun checkNetworkConnection(): Boolean {
//Make call here to start checking on network connection and return a boolean
//return true if connected to the internet
//return false if not connected to the internet
}

Answer 1

just create a state variable in your viewmodel such as:
private val _connectivityState = mutableStateOf(Status. Unavailable)
val connectivityState: State<Status> = _connectivityState // this is for exposing UI if you need
then there are two possible scenarios:
1- if you want to do some work in case of connectivity changes, directly use a combine flow and connect your different flows such as:
fun someWork() {
viewModelScope.launch(Dispatchers.IO) {
combine(
ConnectivityObserver.observe(),
YourAnotherWorkStuffReturnsAFlow()
).collect { status, payloadOfWork ->
_connectivityState = status
when(status) {
// check payload and do work
}
}
}
}
2- directly call your observer as above in a separate vievmodelScope and update value on collect changes. the code will be same except the combine part and other workload such as :
init{
getConnectivity()
}
fun getConnectivity() {
viewModelScope.launch(Dispatchers.IO) {
ConnectivityObserver.observe().collect { status ->
_connectivityState = status
}
}
}
Finally, by using two variables, which are given in the beginning, you will ensure that UI cannot make any changes on _connectivityState as only the connectivityState is exposed to the UI and it only observes through _connectivityState.