Hi, With the new Kotlin feature Prototype of Context Receivers how can we create an extension functi...

# android

[Sergio C.]

Hi,
With the new Kotlin feature Prototype of Context Receivers how can we create an extension function for this nesting and make it just one line? I've seen something online but I lost the link.

viewLifecycleOwner.lifecycleScope.launch {
    viewLifecycleOwner.repeatOnLifecycle(Lifecycle.State.STARTED) {
        locationProvider.locationFlow().collect {
            // New location! Update the map
        }
    }
 }

[Semir Rahic]

Hi Sergio,

do you mean this:

inline fun <T> Flow<T>.launchAndCollectIn(
owner: LifecycleOwner,
minActiveState: Lifecycle.State = Lifecycle.State.STARTED,
crossinline action: suspend CoroutineScope.(T) -> Unit
) = owner.lifecycleScope.launch {
owner.repeatOnLifecycle(minActiveState) {
collect {
action(it)
}
}
}

Then call from Fragment like this:

viewModel.myFlow.launchAndCollectIn(this, Lifecycle.State.STARTED) {
    //nasty stuff
}

There was a similar thing with repeatingJob

[Sergio C.]

yes something like that

[Sergio C.]

I found the twit: https://mobile.twitter.com/_takahirom_/status/1491213998188273665

[Sergio C.]

there's a new context on top context(Fragment) and simplifies it some more

[Sergio C.]

now I'm trying to use this enabling -Xcontext-receivers
Where do we enable this flags?

[Semir Rahic]

with the Context stuff you get rid of the owner parameter…

[Semir Rahic]

usually inside the gradle project properties (not sure where this parameter belongs)

[Sergio C.]

we need beta versions of AS kotlin plugin etc, I'll leave it for now