ivanalvarado

const val ARGUMENT_USER_ID = "ARGUMENT_USER_ID"
 
class UserDetailActivity : AppCompatActivity() {
 
    // Pass Intent Argument to ViewModel
    private val userDetailViewModel by lazy {
        injector.userDetailViewModelFactory.create(
            userId = intent.getIntExtra(ARGUMENT_USER_ID, 0)
        )
    }

ivanalvarado

class MyApplication : Application() {
  
    // ...
     
    val component: AppComponent by lazy {
        DaggerAppComponent.builder()
            .application(this)
            .build()
    }
}

ivanalvarado

@Component(modules = [AssistedInjectModule::class])
@Singleton
interface ApplicationComponent {
    // ...
  
    @Component.Builder
    interface Builder {
        @BindsInstance
        fun application(application: Application): Builder
        fun build(): AppComponent

ivanalvarado

class UserDetailViewModel @AssistedInject constructor(
    private val userRepository: UserRepository,
    @Assisted private val userId: Int
) : ViewModel() {
 
    private val reloadTrigger = MutableLiveData<Boolean>()
    private val userDetail: LiveData<UserDetailModel> = Transformations.switchMap(reloadTrigger) {
        userRepository.getUserDetail(userId.toString(), reloadTrigger.value!!)
    }
 

ivanalvarado

// module level gradle file
dependencies {
    /* Dagger 2 - Assisted Inject */
    compileOnly 'com.squareup.inject:assisted-inject-annotations-dagger2:0.3.3'
    kapt 'com.squareup.inject:assisted-inject-processor-dagger2:0.3.3'
}

ivanalvarado

const val ARGUMENT_USER_ID = "ARGUMENT_USER_ID"
  
class UserDetailActivity : AppCompatActivity() {
  
    @Inject
    internal lateinit var viewModelFactory: ViewModelProvider.Factory
    private lateinit var userDetailViewModel: UserDetailViewModel
 
    override fun onCreate(savedInstanceState: Bundle?) {
        // ...

ivanalvarado

class UserDetailViewModel @Inject constructor(
    private val userRepository: UserRepository
) : ViewModel() {
 
    private lateinit var userId: String
    private val reloadTrigger = MutableLiveData<Boolean>()
    private val userDetail: LiveData<UserDetailModel> = Transformations.switchMap(reloadTrigger) {
        userRepository.getUserDetail(userId, reloadTrigger.value!!)
    }

ivanalvarado

class UserListViewModel @Inject constructor(private val userRepository: UserRepository) : ViewModel() {

    init {

    }

    // DON'T DO THIS
    fun getUsers(): LiveData<List<UserModel>> {
        return userRepository.getUsers()
    }

ivanalvarado

// DON'T DO THIS
class UserListActivity : AppCompatActivity() {

    @Inject internal lateinit var viewModelFactory: ViewModelProvider.Factory
    private lateinit var userListViewModel: UserListViewModel
    private lateinit var swipeRefreshLayout: SwipeRefreshLayout

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

ivanalvarado

class UserListViewModel @Inject constructor(private val userRepository: UserRepository) : ViewModel() {

    private val reloadTrigger = MutableLiveData<Boolean>()
    private val users: LiveData<List<UserModel>> = Transformations.switchMap(reloadTrigger) {
        userRepository.getUsers()
    }

    init {
        refreshUsers()
    }