If I'm using

Flow

as the bridge between a VM and a fragment, how can I ensure that the callback I use for the flow is initialized before I need It? The way I'm approaching it now seems like an antipattern.

private var loadedPosts: List<Post> = emptyList()
    private lateinit var loadedPostsCallback: LoadedPostsCallback
    val posts: Flow<List<Post>> = callbackFlow {
        val callback = object : LoadedPostsCallback {
            override fun setLoadedPosts(posts: List<Post>) {
                loadedPosts = loadedPosts + posts
                offer(loadedPosts)
            }
        }
        loadedPostsCallback = callback

        awaitClose()
    }

Why can't you init

loadedPostsCallback

inside

callbackFlow

?

@Dominaezzz I did, but the flow wasn't actually being initialized because that block didn't get run until

collect

was being called

You could call

produceIn

and turn the flow into a channel.

I ended up with this

Hmm, I feel like this could definitely be improved somehow.

yeah it definitely doesn't feel as easy as LiveData. There's got to be something I'm missing

You should be able to do this with,

callbackFlow {}.onEach {}.launchIn(coroutineScope)

.

not quite sure how to apply that to something like the snippit above

Can

loadedPostsCallback

be initialised and registered inside a flow? (Do you need a context or smth)

no, but I did need to make the callback from within the flow or else I wouldn't be able to offer in the flow scope

Ah, I misread. Channel seems to be what you need.

cool 🙂