I need to get context in view model , I am trying ...

# compose

[Jitendra]

I need to get context in view model , I am trying to get using localcontext but it is keep giving error @composable invocation can only happen from the context of composable function, what is the best way to get context/activity instance in viewsmodel

[Francesc]

Context is better avoided in viewmodels. If you still want to go that route, inject the application context using Hilt or whichever DI you're using. However, I discourage that approach.

[Advitiay Anand]

Since viewmodel has its own lifecycle, it's possible for the context (that it is holding) to go stale (no longer in memory), therefore you should avoid holding such references in the viewmodel.

A simpler approach would be to create a function in the viewmodel, and pass it as a callback in your composables. Something like this:

class MyViewModel : ViewModel() {
    fun useContextToDoSomething(context: Context) {
        // Do something
    }

class MainActivity : ComponentActivity() {
    val viewModel: MyViewModel by viewModels()

setContent {
        MyComposable(doWithContext = viewModel.useContextToDoSomething)
    }
}

@Composable
fun MyComposable(doWithContext: (Context) -> Unit) {
    val context = LocalContext.current

Button(onClick = { doWithContext(context) }) {
        Text("Click Me!")
    }
}

This way, the context is always fresh, but the functionality is still kept in the viewmodel, away from the UI

[kotlinforandroid]

To further elaborate: A ViewModel can live longer than the View that uses it. That's why the reference can go stale. The View gets GC'd and thus its Context as well. A ViewModel in Compose is often bound to the NavGraph and thus outlives its View counterpart.