If I use `asFlow ` on a closed `ConflatedBroadcastChannel` w

Question

If I use `asFlow ` on a closed `ConflatedBroadcastChannel` will it receive the latest element sent before it was closed or will the flow be empty

elizarov · Answer

It will be empty

dave08 · Answer

So if I need to ensure that I receive that latest element I d have to not close that channel then the flow would never end is there any better way

elizarov · Answer

Why would you need the channel to be a broadcast one What do you use it for

dave08 · Answer

I need to download files in one part of the android app in a service but I need to let the UI know of the state of those downloads So I have nested `ConflatedBroadcastChannel`s one to manage the downloads the other each download s progress there are other things to be done after the download There are different states some files aren t ready to be downloaded or aren t compatible available and the UI needs to display this accordingly

dave08 · Answer

The progress works fine but I think the other things get sent before the UI has a chance to do `asFlow ` so if I close the channel it won t receive them if I don t the UI will keep on listening to an invalid channel

elizarov · Answer

Why whould you need to ever close them

dave08 · Answer

The inner channels are just temporary while the service is running they get sent using the outer channel for each one we `launch` a coroutine to listen to the changes it will report wouldn t those coroutines just pile up and just waste memory as new ones come in that are more relevant

dave08 · Answer

Each item in the recyclerview listens to such flows to update its content accordingly

elizarov · Answer

If you launch just one coroutine to listen for changes then I don t see why would you need a broadcast channel Just use a regular channel

dave08 · Answer

I need to listen to that both to update the recyclerview and the notification

dave08 · Answer

Each one has it s own class and is managed in a different module

elizarov · Answer

Ok Then you can avoid closing them anyway As long as your views will stop subscribing to those broadcast channels when no longer show they will garbage collected when no views remain showing them You don t have to close them to make them eligible for GC

dave08 · Answer

If I use `cancel someException ` or `close someException ` will a `catch ` on the `Flow` resulting from `asFlow ` catch it or will it throw since anyways those emissions are really a final state anyways

dave08 · Answer

If so I could just use such a ```fun getDownloadListener = downloadBroadcastChannel asFlow catch when it is ExceptionOne gt emit StateOne ``` and reuse that

dave08 · Answer

Even keeping the channel open I still don t receive those emissions for some reason otherwise

dave08 · Answer

The progress is reported fine though

dave08 · Answer

Originally I thought it was because the progress gets sent when the channel is still open but when I send those the channel is closed by the time the UI starts listening but that doesn t seem to be the case