Is there any possibility to convert the new start activity f

Question

Is there any possibility to convert the new start activity for result api into a Kotlin Completable Deferred taking into account destroyed state of the caller Activity

Ian Lake · Answer

Any type of `Deferred` inline callback won t work over configuration change or process death or recreation which is specifically why the callback needs to be registered ahead of time as per the docs <https developer android com training basics intents result register>

Ian Lake · Answer

You can certainly `tryEmit ` from that callback to your own `MutableSharedFlow` that you collect on

Doru N. · Answer

It s a bit new to me the usage of SharedFlow basically I need to streamline somehow the start for result api

Ian Lake · Answer

You could do the same thing with a `ConflatedBroadcastChannel` `MutableSharedFlow` is the replacement as per <https blog jetbrains com kotlin 2020 10 kotlinx coroutines 1 4 0 introducing stateflow and sharedflow >

Doru N. · Answer

My use case is that I call another process via aidl which may return a pending intent if user has to confirm security pin and when that completes I return the data from activity result and continue the flow with it

Ian Lake · Answer

the point is that the receiving the result is separate from the `launch` as they can and do occur completely separately

Ian Lake · Answer

And there s no guarantee that any coroutine context lambdas etc you have available to you at `launch` time will exist when the callback fires

Doru N. · Answer

So basically I need to break the flow of the use case into before launch and after result

Doru N. · Answer

My backend developer had created a function which takes a synchronous callback as a param of which implemention I had to provide This implemention should consist of calling another process via aidl which may in turn start an activity wait for its result and return the data to continue the function call

Ian Lake · Answer

Yeah your activity could be recreated due to a config change or your process killed due to low memory any time after the `launch`

Doru N. · Answer

I thought I could use suspended functions here and make use of CompletableDeffered await which could have done the entire process very smooth

Doru N. · Answer

But I guess I need to reconsider creating the callback asynchronously

Ian Lake · Answer

With the Activity Result API you need to register your callback prior to being started i e as part of your component s start up You can t call it inline with your `launch` precisely because of the config changes and process death cases

Ian Lake · Answer

That s intentional and what makes the Activity Result API actually something that works 100 of the time slightly smiling face

Doru N. · Answer

Well thanks for all the info you provided Ian