Host and Container

Desktop only. A desktop window shows several contents at once, and PulseContainer sits above their ViewModels so they can work together. The host creates it and wraps the contents in PulseHost. It provides three coordination capabilities: broadcast, unicast handling, and view refresh.

Creating a Container

Define a class that takes the list of ViewModels you want to coordinate, and instantiate it at the same level as those ViewModels.

class AppContainer(
    viewModels: List<PulseViewModel<*, *, *, AppBroadcast, AppUnicast>>,
) : PulseContainer<AppBroadcast, AppUnicast>(viewModels = viewModels)

val sidebarViewModel = rememberPulseViewModel { SidebarViewModel() }
val contentViewModel = rememberPulseViewModel { ContentViewModel() }
val container = rememberPulseContainer {
    AppContainer(viewModels = listOf(sidebarViewModel, contentViewModel))
}

Broadcast

Send a typed message to all registered ViewModels simultaneously. Every ViewModel in the list receives onReceive(AppBroadcast.UserLoggedOut) and reacts independently.

container.broadcast(AppBroadcast.UserLoggedOut)

When to use Broadcast

• Synchronizing state across multiple ViewModels (e.g., theme change, locale change)
• Notifying all ViewModels of a global event (e.g., session expiry, network reconnected)
• Propagating data that multiple ViewModels need (e.g., updated user profile)

View Refresh

Force the entire Compose view tree under PulseHost to reconstruct.

What gets reset?

• Compose state (e.g., remember { } inside Composables) is reset
• ViewModel state (values in PulseViewModel.state) is preserved

container.refresh()

When to use Refresh

• Applying a theme or locale change that affects the whole layout
• Recovering from a corrupted Compose state
• Forcing re-creation of composables that don't respond to state changes

Using inside PulseHost

PulseHost reads the Container's internal key and wraps content in a CompositionLocalProvider. PulseContent composables inside PulseHost automatically respond to refresh():

PulseHost(container = appContainer) { onRefresh, onBroadcast ->
    // onRefresh() calls container.refresh()
    // onBroadcast(b) calls container.broadcast(b)

    Button(onClick = { onBroadcast(AppBroadcast.Sync) }) {
        Text("Sync All")
    }
    Button(onClick = { onRefresh() }) {
        Text("Refresh View")
    }
}