Hi there! I have trouble integrating synchronous c...

# coroutines

[ubu]

Hi there! I have trouble integrating synchronous code with coroutines, in order to get that broadcasting feature I was able to implement using `RxJava`:

class Handler : MessageHandler {

    private val channel = Channel<Message>(1)

    override fun handle(message : Message) {
        // TODO send event.
    }

    fun send(event : Message) {
        
    }

/*
    fun observe() : Channel<Message>
    fun observe() : Flow<Message>
*/
}

When having `RxJava`’s subjects, I could call onNext(), let observers consume it by exposing some Observable. Is there a way to do the same with Coroutines? I need to expose some methods that allow to observe stream of events received in handle(message : Message) method. Thanks a lot in advance!

[zak.taccardi]

expose your channel into a flow (consumeAsFlow() or receiveAsFlow())

[zak.taccardi]

send data to teh channel

[zak.taccardi]

if you need subject-like behavior

[ubu]

@zak.taccardi, thanks for helping. Could I implement that without marking my method with suspend modifier?

[zak.taccardi]

yes

[zak.taccardi]

https://github.com/Kotlin/kotlinx.coroutines/issues/1490

[ubu]

@zak.taccardi, how do you send events to your channel?

[zak.taccardi]

with channel.send(..) if I am in a coroutine or channel.offer(..) if I am not

[ubu]

thanks!

[zak.taccardi]

note that if you use channel.offer(..), the Channel’s capacity comes into play

[zak.taccardi]

https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines.channels/-channel/

[ubu]

could we implement some kind of coroutines bus using channels?

[zak.taccardi]

not just with Channels, you’d need Flow<T>

Channels are for communicating between coroutines, or into one from outside of one, and Flow<T> is for exposing an API of multiple events of T

[zak.taccardi]

Channels are a communication primitive

[Pablichjenkov]

check this for an event bus based on coroutines:
https://github.com/Daniil-Pavenko/coroutines-event-pipe

[Pablichjenkov]

However, although Event Bus is a great architecture on Server Side. Android popular implementations I consider are very poor.