In the project, I just joined I found strange `@Co...

# compose

[dawidhyzy]

In the project, I just joined I found strange @Composable usage

class SomeViewModel(
    repository: SomeRepository,
) : ViewModel() {

    val something: State<String?>
        @Composable
        get() = repository.something.collectAsState()
}

what could be the implication of including ViewModel in composition?

[jannis]

I don't see any memory leaks here. Maybe some unnecessary subscriptions. Normally you want your Composable function outside of your ViewModel.
I'd ditch the getter function and move the collectAsState() function to then UI.

[dawidhyzy]

For sure this needs to go to UI and Flow needs to be converted to StatFlow using stateIn.

[dawidhyzy]

But it's that circular reference as composable has reference to ViewModel and vice versa

[Stylianos Gakis]

Where does ViewModel have a reference to the composable?

[dawidhyzy]

isn’t the composable function in a body of the ViewModel?

[Stylianos Gakis]

ViewModel is allowed to have @Composable functions. Functions annotated like that aren’t always about emitting UI, in this case it’s returning a value, and that’s completely fine.

[dawidhyzy]

Do you see any advantage of using this instead of converting Flow to StateFlow?

[Stylianos Gakis]

I mean, I probably wouldn’t do it this way, but I don’t see something wrong with it. Could be missing something though 🤷‍♂️
Also this snippet makes it seem like the something is a StateFlow itself, since you’re using the collectAsState without any parameters, is that the case?

[dawidhyzy]

Because it’s StateFlow mind blown I just checked repository implementation.

[Stylianos Gakis]

Yeah, that’s probably a bit weird, to have a hot flow coming from the Repository, but ignoring that, then this looks fine I guess. The alternative is you do .something here and you simply move the collectAsState() in the UI, it’s pretty much the same thing I guess.