What is the best way to handle

Flow

on device rotation in Android if you are only using

Flow

(without

LiveData

)? I see that Dropbox Store library caches the latest and provides when it is requested again. https://github.com/dropbox/Store

The first time you call to suspend store.get(key), the response will be stored in an in-memory cache and in the persister, if provided. All subsequent calls to store.get(key) with the same Key will retrieve the cached version of the data, minimizing unnecessary data calls.

Since the Flow is cold it is going to be collected evertime.

https://developer.android.com/topic/libraries/architecture/viewmodel Just use a ViewModel which retains its data on configuration change. You would need a LiveData 🙈

Is it the only way ? 😞 I know that there is a DataFlow (or StateFlow) draft -> https://github.com/Kotlin/kotlinx.coroutines/pull/1354

It’s still not going to retain it’s state on configuration change.

Then can we say we should not use Flow in View layer?

You could use it, but it’s not going to retain its state if you don’t save it somewhere which survive configuration change.

You could used savedstatehandle for view models. https://developer.android.com/topic/libraries/architecture/viewmodel-savedstate

val statefulFlow = flow {
    emit(savedState.get(...))
    actualFlow.collect { emit(it) }
}

Your

Flow<T>

should be backed by a

ConflatedBroadcastChannel<T>

until

StateFlow<T>

arrives in the next coroutines version.

ConflatedBroadcastChannel<T>

behaves quite similarly to

LiveData<T>

without the main thread limitation