Facade

ViewModel

ViewModels

I am currently developing an android service app. A problem arose while developing a foreground service app. This is the situation when the activity gets data from the service. One way is to use a bind service and call a method from the service instance.
Another way is to get data using intents.

I've searched a lot, but almost all of them are using intents. If the lifecycle fits well, isn't it convenient and good to call a function as a bind service? I'd like to hear your opinion.
(In the service, it does not actually work, but creates and manages a working thread.)

class App : Application() {
    private var baseCtx: Context? = null
    private var appCtx: Context? = null
    private var baseRes: Resources? = null

    override fun attachBaseContext(base: Context) {
        val ctx = baseCtx ?: base.createLocalizedContext(Locale.ENGLISH).also {
            baseCtx = it
        }
        super.attachBaseContext(ctx)
    }

    override fun getApplicationContext(): Context {
        return appCtx ?: super.getApplicationContext().createLocalizedContext(Locale.ENGLISH).also {
            appCtx = it
        }
    }

    override fun getResources(): Resources {
        return baseRes ?: baseContext.createLocalizedContext(Locale.ENGLISH).resources.also {
            baseRes = it
        }
    }
}

override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        val themedContext = ContextThemeWrapper(
            inflater.context,
            R.style.Theme_LocalizedFragment_Green // apply brand them green
        )
        val local = getLocal() // get local from local storage
        if (requiredTranslation) {
            themedContext.applyOverrideConfiguration(
                requireContext().createLocalizedConfiguration(local)
            )
        }
        val themedInflater = inflater.cloneInContext(themedContext)
        return super.onCreateView(themedInflater, container, savedInstanceState).apply {
            // adjust layout direction as per local
            ViewCompat.setLayoutDirection(this, TextUtilsCompat.getLayoutDirectionFromLocale(local))
        }
    }

Hey Cicero,
Using interface is a matter of Clean Code Architecture, so yes we are using interfaces with UseCases. Please whenever you need to add a new one make sure that you do an interface for.
This project is intended to be big and continues project, so if we are going to support Unit test in future then we need to make sure that we can test each part separately.
The ViewModel is the only exception at the moment because Koin does not accept interfaces when we define the ViewModel. If we you know a way then please tell me to add interfaces to ViewModels.

suspend fun fetch(): List<Item>

suspend fun fetch(): Result<List<Item>, FetchError>

For coroutines and flows, you should use Kotlin's built-in error-handling mechanism.

@Preview
@Composable
fun LoginScreenPreview(){
    val navController = rememberNavController()
    val main: MainActivity = MainActivity()
    val myfactory = MainViewModelFactory(Database.getInstance(main.applicationContext).Dao, main.application)
    val viewModel: MainViewModel = viewModel(
        factory =myfactory
    )
    //TextField(value ="xxx", onValueChange ={} )
    LoginScreen(navController,  viewmodel = viewModel)
}

class MainViewModelFactory(
    private val dataSource: Dao,
    private val application: Application
): ViewModelProvider.Factory{
    @Suppress("unchecked_cast")
    override fun <T : ViewModel> create(modelClass: Class<T>): T {
        if (modelClass.isAssignableFrom(MainViewModel::class.java)) {
            return MainViewModel(dataSource, application) as T
        }
        throw IllegalArgumentException("Unknown ViewModel class")
    }
}