Mastering Android Architecture: A Deep Dive into UI, Domain, and Data Layers

This guide is a resume of Guide to app architecture.

A blueprint for success — UI, domain, data

In modern app development, clean and scalable architecture is crucial. Android’s official architecture guidelines emphasize separating concerns across different layers: UI, domain, and data. This article dives into each of these layers and how they interact to create robust Android applications.

UI Layer

The UI Layer is responsible for displaying data and capturing user interactions. In Android , Jetpack Compose allows for a declarative approach to building UIs, making the process more efficient and less error-prone.

@Composable
fun UserProfileScreen(viewModel: UserProfileViewModel) {
    val userProfile = viewModel.userProfile.observeAsState()

    // Displaying data based on the state
    userProfile.value?.let { profile ->
        Column {
            Text(text = "Name: ${profile.name}")
            Text(text = "Email: ${profile.email}")
        }
    }
    
    // Handling user actions
    Button(onClick = { viewModel.onLogout() }) {
        Text("Logout")
    }
}

The UI observes changes in userProfile using Jetpack Compose’s observeAsState().

User interactions like the button click onLogout() trigger actions in the ViewModel.