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kotlinlang

I’m trying to use ViewModel + LiveData, as seen <https://developer.android.com/jetpack/compose/interop#viewmodel> however the code sample (in thread reply) always shows null

```@Composable
fun LegalBodyContent(contentPadding: InnerPadding = InnerPadding(), onLegal: () -&gt; Unit) {
  val viewModel: MyViewModel = viewModel()
  val user = viewModel.user.observeAsState()
  Text(text = "${user.value}")
}


class MyViewModel: ViewModel() {
  private val userId: LiveData&lt;String&gt; = MutableLiveData()
  val user = userId.switchMap { id -&gt;
    liveData {
      while(true) {
        emit("Test string")
        delay(30_000)
      }
    }
  }
}```

I thought that `emit("Test string")` , would set it?

With switchMap you are mapping the value received in userId to whatever livedata returned in the block

Right and that doesn’t happen on the initial initialization

So to kick off say a network request, would I need to use onCommit to then call a method on the view model to do that?

If there's not value in userId, you won't map anything and thus won't have anything in user

It depends where you're getting the userId from.

At the moment I’m using a single activity for the entire UI of my app using <https://github.com/zsoltk/compose-router>

Ask yourself the right questions: 
- How can I get my current userId ? 
- With this userId how can I get my user ? 

I'm not sure you need to use a livedata for the userId. You could just use `val user = livedata{}` 

And load and emit your user inside the livedata block.

Ah sorry, what I was aiming to do was to load data (using Fuel) in a few of my compose functions that represent different screens. A lot of the examples I saw used multiple activities.

If you just want to learn and play with compose maybe find some simpler use cases. The codelabs are good starting points. 

You can also take a look at Google samples (or any other sample you can find in this channel) if you need help with your app architecture.

I think the Android Compose examples (on Github) all used either multiple activities / fragments. Thanks for your help :slightly_smiling_face: