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@chrisbanes
Last active October 25, 2022 21:29
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ScopedViewModel
open class ScopedViewModel : ViewModel() {
private val job = Job()
protected val scope: CoroutineScope = job + Dispatchers.Main
override fun onCleared() {
super.onCleared()
job.cancel()
}
}
class DetailViewModel : ScopedViewModel() {
fun startTask() {
scope.launch {
// Switch the 'background' thread
withContext(Dispatchers.Default) {
// do your long-running thing
}
// We're now back on the Android's Main thread (since we're using
// the ScopedViewModel's scope)
updateUi()
}
}
}
@XinyueZ
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XinyueZ commented Sep 13, 2018

launch // no launch(ui){...} ?

@aouerf
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aouerf commented Sep 13, 2018

@XinyueZ UI is deprecated in favour of Dispatchers.Main. And since he set that as the coroutine context for theViewModel, launch uses that by default.

That being said, I prefer the default dispatcher to be Dispatchers.Default and switch to the main (or IO, but this shouldn't be necessary with the experimental scheduler) context when necessary.

@XinyueZ
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XinyueZ commented Sep 13, 2018

I C, got it, I have converted my project from experimental to non-experimental and I have seen a lot different things.

@XinyueZ
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XinyueZ commented Sep 13, 2018

I prefer

    override val coroutineContext: CoroutineContext
        get() = Dispatchers.Main + job

@loki666
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loki666 commented Sep 14, 2018

private val scope: CoroutineScope = job + Dispatchers.Main
doesn't compile... it expect a CoroutineScope

@marenovakovic
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Yes, it doesn't compile, I have solved it like this:
protected val scope: CoroutineScope = CoroutineScope(Dispatchers.Main + job)

@iam1492
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iam1492 commented Nov 10, 2018

Great stuff!
Is it ok implement CoroutineScope from viewModel and just use launch instead of scope.launch?

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