Hey guys, I have a question regarding MutableStateFlow. I have a MutableStateFlow in my repo which i...

# coroutines

[Aditya Wasan]

Hey guys, I have a question regarding MutableStateFlow. I have a MutableStateFlow in my repo which is being observed in the ViewModel. However, the ViewModel is not receiving any updates.

Here's the StateFlow that I have in my repository

private val _isCacheReady = MutableStateFlow(false)
val isCacheReady = _isCacheReady.asStateFlow()

After filling up the cache, I'm updating the value

_isCacheReady.value = true

And here's the observing code

init {
  lobstersRepository.isCacheReady.onEach {
    _savedPosts.value = lobstersRepository.getAllPostsFromCache()
  }.launchIn(viewModelScope)
}

[Dominaezzz]

Hmm, that looks fine. If you add `println`s in onEach , do they get printed?

[Aditya Wasan]

Yeah, so I've tried debugging everything and the onEach is called the first time when ViewModel initialises. However, onEach is not called again when I set _isCacheReady.value = true.

[Dominaezzz]

You're sure _isCacheReady.value set to true already?

[Aditya Wasan]

Yep, tried logging the value of _isCacheReady.value after updating it.

[Dominaezzz]

The first time onEach is called, is it true? (That's what I meant)

[Aditya Wasan]

Oh sorry. Yeah it is false. I know MutableStateFlow won't re-emit the same state.

[Dominaezzz]

Ah, I've got no idea then.

[Zach Klippenstein (he/him) [MOD]]

I’m not sure either, but just to confirm the basics – is the scope getting cancelled early for some reason? Add a .onCompletion { println("complete: $it") } before your launchIn

[Aditya Wasan]

I don't think it should cancel because it is a viewmodel but I'll definitely check it.

[Aditya Wasan]

Just tried it, onCompletion {} is called after the app is closed.

[Aditya Wasan]

Here's the complete PR if anyone is interested in checking the app.

https://github.com/msfjarvis/compose-lobsters/pull/101