How to implement the MVVM pattern in applications using Jetpack Compose for UI

In Jetpack Compose, the MVVM pattern is implemented through the separation of:

• Model — business logic and data.
• ViewModel — holds UI state and handles interaction logic.
• View (Compose UI) — displays data and responds to state changes.

Example:

class MyViewModel : ViewModel() {
    // UI state, for example, a text field
    var text by mutableStateOf("")
        private set

    fun onTextChanged(newText: String) {
        text = newText
    }
}

@Composable
fun MyScreen(viewModel: MyViewModel = viewModel()) {
    val text = viewModel.text
    TextField(
        value = text,
        onValueChange = { viewModel.onTextChanged(it) },
        label = { Text("Enter text") }
    )
}

Here, the ViewModel contains the state and methods to modify it. The Compose UI subscribes to the state via mutableStateOf, automatically updating upon changes.

This approach ensures a clean separation of concerns and simplifies testing.