markchristopherng

/**
 * A generic class that holds a value with its loading status.
 * @param <T>
</T> */
data class Resource<out T>(val status: Status, val data: T?, val message: String?) {
    companion object {
        fun <T> success(data: T?): Resource<T> {
            return Resource(SUCCESS, data, null)
        }

markchristopherng

class SimpleViewModel : ViewModel() {

    var data: LiveData<String> = MutableLiveData()

    var loading: LiveData<Boolean> = MutableLiveData()

    var error: LiveData<Throwable> = MutableLiveData()
}

markchristopherng

class StateLiveData<T> : MutableLiveData<T>() {

    val state = EventLiveData<State>()

}

markchristopherng

fun refreshSavedBillers() {
        payBillManager.getAll()
                .compose(defaultOptions())
                .autoDisposable()
                .subscribe({
                    displaySavedBillers(it)
                }) { Timber.d(it) }
}

markchristopherng

class EventLiveData<T> : MutableLiveData<T>() {

    private var isRead: AtomicBoolean = AtomicBoolean(false)

    /**
     * ensure the event is non-null and can only been seen once
     */
    fun observeEvent(owner: LifecycleOwner, observer: Observer<T>) {
        super.observe(owner, Observer {
             if (it != null && isRead.compareAndSet(false, true)) {

markchristopherng

class StateLiveData<T> : MutableLiveData<T>() {

    val state = EventLiveData<State>()

    init {
        clearState()
    }

    fun post(observable: Observable<T>, successOnFirstValue: Boolean = true): Disposable {
        postLoading()

markchristopherng

open class BaseViewModel : ViewModel() {

    private val disposableList = mutableListOf<Disposable>()

    // integration with rx
    fun <T> Observable<T>.subscribe(stateLiveData: StateLiveData<T>, successOnFirstValue: Boolean = true) = stateLiveData.post(this, successOnFirstValue).also { disposableList.add(it) }

    override fun onCleared() {
        disposableList.filter { !it.isDisposed }.forEach { it.dispose() }
        disposableList.clear()

markchristopherng

abstract class BaseActivity : AppCompatActivity() {

    fun <T> LiveData<T>.observe(observer: (T?) -> Unit) = observe(this@BaseActivity, Observer { observer(it) })

    fun <T> LiveData<T>.observeNonNull(observer: (T) -> Unit) = observe { if (it != null) observer(it) }

    fun <T> EventLiveData<T>.observeEvent(observer: (T) -> Unit) = observeEvent(this@BaseActivity, Observer { if (it != null) observer(it) })

    inline fun <reified T : BaseViewModel> getViewModel(): T = ViewModelProviders.of(this)[T::class.java]

markchristopherng

class PayBillViewModel : BaseViewModel() {

    var manager: PayBillManager = PayBillManager()

    var bills: StateLiveData<List<SavedBill>> = StateLiveData()

    fun loadBills() {
        manager.getAll()
                .subscribe(bills)
    }

markchristopherng

class PayBillActivity : BaseActivity() {

    lateinit var payBillViewModel : PayBillViewModel

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

        payBillViewModel = getViewModel()
        payBillViewModel.loadBills()