Hello on my presenter I'm getting a `CoroutineScope` and a `CoroutineDispatcher` is it mandatory to...

# coroutines

[Pablo]

Hello on my presenter I'm getting a CoroutineScope and a CoroutineDispatcher is it mandatory to implement in the onDestroy() the cancel of them? what happens if I don't do this?

[andylamax]

It is mandatory to do so so that you may not have leaking coroutines running while the scope of your presenter is destroyed

[Pablo]

So, it's mandatory that on every onDestroy of an Activity/Fragment I do coroutineScope.cancel() and coroutineDispatcher.cancel()?

[andylamax]

Just the scope. No need to cancel the dispather

[Ian Lake]

Note that Activities and Fragments already have a scope that is cancelled for you in onDestroy(): https://developer.android.com/topic/libraries/architecture/coroutines#lifecyclescope

[Pablo]

@Ian Lake  thanks for this note though, the thing is, my fragment/Activity have a @Inject lateinit var myPresenter : Presenter
And this presenter already have as a parameter a MainScope() , so, even if they cancell their own scope they won't cancell the one created on my presenter, right?

[Ian Lake]

Unless you hook up the lifecycleScope as the parent scope, it won't automatically cancel, that's correct

[Pablo]

And if I use myActivity.lifecycleScope then it's not necessary to cancel in the onDestroy, right? @Ian Lake

[Ian Lake]

It will do that automatically, yes