Android 有进展的干净体系结构用例[无RxJava]
我在试图找出实现用例的最佳方法时遇到了一个问题。我见过这样的例子: 谷歌I/O安卓应用程序 我不喜欢的是:Android 有进展的干净体系结构用例[无RxJava],android,kotlin,kotlin-coroutines,clean-architecture,Android,Kotlin,Kotlin Coroutines,Clean Architecture,我在试图找出实现用例的最佳方法时遇到了一个问题。我见过这样的例子: 谷歌I/O安卓应用程序 我不喜欢的是: 您将在UI中接收结果并在那里做出许多决策 无进展 我认为这是对上述内容的升级: Android架构蓝图 他们正在使用协同程序,现在结果出现在ViewModel中,而且效果要好得多。但同样:没有进展 我这里的问题是每个人都在使用RxJava,因为其他人都在使用它。我看到很多人认为这是“在后台执行任务”的东西。但这对我来说太过分了。我不需要它 我已经看到了一些关于协同程序频道的例子,但
- 您将在UI中接收结果并在那里做出许多决策
- 无进展
class ProduceValueWithProgressUseCase @Inject constructor(
private val executor: Executor
) {
operator fun invoke(): Flow<Result<Int, Int>> {
return callbackFlow {
val callback = object : CallbackProgress {
override fun onProgress(result: Int) {
offer(Result.Loading(result))
}
override fun onSuccess(result: Int) {
offer(Result.Success(result))
close()
}
override fun onError(e: Exception) {
offer(Result.Error(e))
close()
}
}
val producer = ValueWithProgressProducer(callback)
executor.execute(producer)
awaitClose {}
}
}
}
是的,基本上Flows API将为我完成这项工作。我甚至创建了一个小应用程序来测试itm,在那里我只生成数字,效果很好。我不喜欢的是:
- 太多的实验常规SAPI注释必须到位。例如这里(很抱歉格式化): @抑制(“无内容到内联”) @实验常规 公共内联fun callbackFlow(@builderReference noinline块:挂起 生产范围(->单位):流量= 渠流(块)
- 在某些时候,我用@Preview注释找到了一些东西。(老实说,我不记得在哪里了。我已经删除了一些东西。)
- 我也试了一下,看看测试将如何进行,但这并不简单。您可以在Blueprinst的代码中看到相同的内容
- 我还混合了执行任务的代码和任务本身。我的意思是使用callbackFlow()
所以最后我看到了一些东西,看起来像是在尖叫着要在明年改变。因此,请给出您的想法。因此,我将根据您在问题描述中提出的内容向您展示一个实现,请随时提出更多问题,甚至提出改进建议 当前的实现基于Kotlin Coroutines 1.3.2的稳定版本 回调接口
interface CallbackProgress {
suspend fun onProgress(result: Int)
suspend fun onSuccess(result: Int)
suspend fun onError(exception: Exception)
}
制作人
迭代并执行回调函数的某些方法。试着模仿你的
class Producer(private val callback: CallbackProgress) {
suspend fun execute(fail: Boolean) {
(0 until 10).forEach {
when {
it < 9 -> callback.onProgress(it)
fail -> callback.onError(InterruptedException("blabla"))
else -> callback.onSuccess(it)
}
delay(500)
}
}
}
互动者
在这里您需要小心,因为排放应该在同一个协同程序中完成,否则您将需要使用非稳定API,例如
为了测试以上内容,我编写了以下内容,其中演示了故障和非故障排放
fun main() = runBlocking {
val useCase = UseCase()
useCase(true).collect {
when (it) {
is State.Loading -> println("State for failure [Loading -> ${it.progress}]")
is State.Success -> println("State for failure [Success -> ${it.value}]")
is State.Error -> println("State for failure [Error -> ${it.exception.message}]")
}
}
useCase(false).collect {
when (it) {
is State.Loading -> println("State without failure [Loading -> ${it.progress}]")
is State.Success -> println("State without failure [Success -> ${it.value}]")
is State.Error -> println("State without failure [Error -> ${it.exception.message}]")
}
}
}
输出
State for failure [Loading -> 1]
State for failure [Loading -> 2]
State for failure [Loading -> 3]
State for failure [Loading -> 4]
State for failure [Loading -> 5]
State for failure [Loading -> 6]
State for failure [Loading -> 7]
State for failure [Loading -> 8]
State for failure [Error -> blabla]
-------------------------------------
State without failure [Loading -> 0]
State without failure [Loading -> 1]
State without failure [Loading -> 2]
State without failure [Loading -> 3]
State without failure [Loading -> 4]
State without failure [Loading -> 5]
State without failure [Loading -> 6]
State without failure [Loading -> 7]
State without failure [Loading -> 8]
State without failure [Success -> 9]
你能发布一些代码片段吗?自2019年8月以来,流量一直稳定。一些转换运算符和终端运算符处于实验和预览阶段,我很确定您不必使用它们就可以实现您想要的结果。@Giorgosnokleus,给您。
callbackFlow
确实不稳定。但是如果你检查一下稳定的API,我很确定你可以实现你想要的,而不需要callbackFlow
,而是普通的Flow
s。不幸的是,我没有在我的机器上玩一个例子,我留下了一个粗略的实现,希望能有所帮助!
class UseCase {
operator fun invoke(fail: Boolean) = flow {
val callback = object : CallbackProgress {
override suspend fun onSuccess(result: Int) {
withContext(coroutineContext) { emit(State.Success(result)) }
}
override suspend fun onError(exception: Exception) {
withContext(coroutineContext) { emit(State.Error(exception)) }
}
override suspend fun onProgress(result: Int) {
withContext(coroutineContext) { emit(State.Loading(result)) }
}
}
Producer(callback).execute(fail)
}
}
fun main() = runBlocking {
val useCase = UseCase()
useCase(true).collect {
when (it) {
is State.Loading -> println("State for failure [Loading -> ${it.progress}]")
is State.Success -> println("State for failure [Success -> ${it.value}]")
is State.Error -> println("State for failure [Error -> ${it.exception.message}]")
}
}
useCase(false).collect {
when (it) {
is State.Loading -> println("State without failure [Loading -> ${it.progress}]")
is State.Success -> println("State without failure [Success -> ${it.value}]")
is State.Error -> println("State without failure [Error -> ${it.exception.message}]")
}
}
}
State for failure [Loading -> 1]
State for failure [Loading -> 2]
State for failure [Loading -> 3]
State for failure [Loading -> 4]
State for failure [Loading -> 5]
State for failure [Loading -> 6]
State for failure [Loading -> 7]
State for failure [Loading -> 8]
State for failure [Error -> blabla]
-------------------------------------
State without failure [Loading -> 0]
State without failure [Loading -> 1]
State without failure [Loading -> 2]
State without failure [Loading -> 3]
State without failure [Loading -> 4]
State without failure [Loading -> 5]
State without failure [Loading -> 6]
State without failure [Loading -> 7]
State without failure [Loading -> 8]
State without failure [Success -> 9]