dmytrodanylyk

// dispatches execution onto the Android main UI thread
private val uiContext: CoroutineContext = UI
 
// represents a common pool of shared threads as the coroutine dispatcher
private val bgContext: CoroutineContext = CommonPool

dmytrodanylyk

private fun loadData() = launch(uiContext) {
    view.showLoading() // ui thread
 
    try {
        val task = async(bgContext) { dataProvider.loadData("Task") }
        val result = task.await() // non ui thread, suspend until task is finished
 
        view.showData(result) // ui thread
    } catch (e: RuntimeException) {
        e.printStackTrace()

dmytrodanylyk

class MainPresenter(private val view: MainView,
                    private val dataProvider: DataProviderAPI
                    private val uiContext: CoroutineContext = UI,
                    private val ioContext: CoroutineContext = CommonPool) {
 
    private fun loadData() = launch(uiContext) { // use the provided uiContext (UI)
        view.showLoading()
 
        // use the provided ioContext (CommonPool)
        val task = async(bgContext) { dataProvider.loadData("Task") }

dmytrodanylyk

val exceptionHandler: CoroutineContext = CoroutineExceptionHandler { _, throwable -> throwable.printStackTrace() }
 
private fun loadData() = launch(uiContext + exceptionHandler) {
    view.showLoading() // ui thread
 
    val task = async(bgContext) { dataProvider.loadData("Task") }
    val result = task.await() // non ui thread, suspend until the task is finished
 
    view.showData(result) // ui thread
}

dmytrodanylyk

var job: Job? = null
 
fun startPresenting() {
    job = loadData()
}
 
fun stopPresenting() {
    job?.cancel()
}
 

dmytrodanylyk

private fun loadData() = async(uiContext) {
    view.showLoading() // ui thread
 
    val task = async(bgContext) { dataProvider.loadData("Task") }
    val result = task.await() // non ui thread, suspend until the task is finished
 
    view.showData(result) // ui thread
}

dmytrodanylyk

data class Result<out T>(val success: T? = null, val error: Throwable? = null)
 
private fun loadData() = launch(uiContext) {
    view.showLoading() // ui thread
 
    val task = async(bgContext) { dataProvider.loadData("Task") }
    val result: Result<String> = task.await() // non ui thread, suspend until the task is finished
 
    if (result.success != null) {
        view.showData(result.success) // ui thread

dmytrodanylyk

private fun loadData() = launch(uiContext) {
    view.showLoading() // ui thread
 
    val task = async(bgContext) { dataProvider.loadData("Task") }
 
    // non ui thread, suspend until the task is finished or return null in 2 sec
    val result = withTimeoutOrNull(2, TimeUnit.SECONDS) { task.await() }
 
    view.showData(result) // ui thread
}

dmytrodanylyk

private fun loadData() = launch(uiContext) {
    view.showLoading() // ui thread
 
    val task1 = async(bgContext) { dataProvider.loadData("Task 1") }
    val task2 = async(bgContext) { dataProvider.loadData("Task 2") }
 
    val result = "${task1.await()} ${task2.await()}" // non ui thread, suspend until finished
 
    view.showData(result) // ui thread
}

dmytrodanylyk

class MainPresenter(private val view: MainView,
                    private val dataProvider: DataProviderAPI) {
 
    private fun loadData() = launch(UI) { // UI - dispatches execution onto Android main UI thread
        view.showLoading()
 
        // CommonPool - represents common pool of shared threads as coroutine dispatcher
        val task = async(CommonPool) { dataProvider.loadData("Task") }
        val result = task.await()