Guys, hi. Question: if I want to use something like PublishSubject from Rx, so I can both emit and s...

# coroutines

[Vsevolod Kaganovych]

Guys, hi. Question: if I want to use something like PublishSubject from Rx, so I can both emit and subscribe to it, what is the analogue in coroutines? Do we still use some kind of Channel or Flow already has this functionality?

[wasyl]

PublishSubject is a BroadcastChannel<T>(1)

[Dominaezzz]

StateFlow is the best available tool right now. SharedFlow is more powerful and will be released within the next 2 months.

[wasyl]

BehaviorSubject can be replaced with a ConflatedBroadcastChannel.

[Dominaezzz]

Ah. In that case, wait for SharedFlow while you use BroadcastChannel(1) .

[Vsevolod Kaganovych]

thank you!

[Javier]

@wasyl then BehaviorSubject equivalent is StateFlow when ConflatedBroadcastChannel dissapear

[wasyl]

Right, I forgot StateFlow is already released and working, I haven’t migrated to it myself yet. It’s a direct replacement for ConflatedBroadcastChannel(1), no (obvious) surprises right?

[Dominaezzz]

Just around closing. It cannot (or doesn't have to) be closed (yet?).

[wasyl]

Thanks! 🙂

[Javier]

It should be I guess @wasyl, they will deprecate ConflatedBroadcastChannel when StateFlow is released

[mateusz.kwiecinski]

I think there is one more difference between StateFlow and ConflatedBroadcastChannel
In case when you set/emit the same value twice StateFlow won’t emit an update

StateFlow conflation is based on equality like distinctUntilChanged operator, unlike conflation in ConflatedBroadcastChannel that is based on reference identity.

https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines.flow/-state-flow/

[travis]

Another possible option: https://github.com/akarnokd/kotlin-flow-extensions#publishsubject