I created a new video about Best Practices for using Kotlin

Question

I created a new video about Best Practices for using Kotlin Coroutines in Android Development Maybe its helpful for someone <https youtu be tVDCpjqQ1Ro>

Joost Klitsie · Answer

cool video Luckily I am not surprised by most of it smile One question In the best practice 4 you mention that you can run work in the `applicationScope` as to make it finish even if the original calling scope is cancelled is the `async` `await` the only way to do this Or are there also other ways

Joost Klitsie · Answer

I ask because Android studio really wants me to turn the `async` `await` into a `withContext applicationScope coroutineContext ` which doesn t really do the same as if you do `withContext`and you cancel during it then the code afterwards will still run and you d have to do an `isActive` check ```suspend fun CoroutineScope test val result = withContext applicationScope coroutineContext delay 200 println producing 5 5 if isActive return println result ```

Stylianos Gakis · Answer

Having a function which is both suspending and an extension on `CoroutineScope` does look a bit suspicious does it not In general if a function is an extension on `CoroutineScope` I expect it to be a fire and continue just like `launch` does Like mentioned And this important quote from the post from Elizarov It leads to the following useful convention every function that is declared as extension on `CoroutineScope` returns immediately but performs its actions concurrently with the rest of the program What are you trying to achieve there Joost I am a bit confused

Joost Klitsie · Answer

< Stylianos Gakis> I tried to do a thing that was mentioned in the video specifically best practice number 4 using async await with a differen scope to make work finish even if the original scope gets cancelled But android studio is giving me a suggestion when I do that to change it to a withContext instead So my question would be is this the best way to achieve this behaviour or is there a better way

Stylianos Gakis · Answer

And why do you need it to be an extension on CoroutineScope to do that In the video I see that a CoroutineScope context is introduced by using the `coroutineScope ` function maybe this is what you wanted to use instead I may be misunderstanding something if yes you could show what you would want your code to look like which doesn t compile and we can take it from there

Joost Klitsie · Answer

It is a test sample

Joost Klitsie · Answer

So it compiles and runs

Joost Klitsie · Answer

I don t have it as actual code but the general idea would be what is the best way to finish work started from a coroutine when the original scope gets cancelled

Joost Klitsie · Answer

Like I load something from the UI I start a network call during this my ui moves away and kills its scope but I still want to finish this backend call

Stylianos Gakis · Answer

If you care for the response I guess you need to do the async approach as shown in the video If you do not you can simply do `val job = appliacationScope launch stuff here job join ` or not even do the join part if you don t care for waiting for it to finish I don t know if you can do this without async if you want the response If someone knows I d love to see it

Joost Klitsie · Answer

cool slightly smiling face thanks btw for the info and the links you shared