Hi, is possible to use coroutines as `EventBus`? i...

# coroutines

[Alireza]

Hi, is possible to use coroutines as EventBus? i found this gist: https://gist.github.com/svenjacobs/57a21405b2dda4b62945c22235889d4a , but filter operator of openSubscription() is mark as deprecated!, is there any better sample code?

[Adam Powell]

use .asFlow() on the broadcast channel and then operator chain from there instead. Strongly consider using offer or declaring your send method suspend instead of `launch`ing internally. The filter followed by map for the cast would be better written .mapNotNull { it as? T } or filterIsInstance

[Adam Powell]

EventBus isn't a particularly scalable pattern though; there are probably better ways to approach your problem.

[Adam Powell]

It's very easy to make a mess, make things hard to debug, and end up with strange latency in unrelated operations. And that's just the tip of the iceberg.

[Alireza]

Thanks @Adam Powell,you are right, i agree that EventBus makes app scalability harden, but at now i have callback hell in my code and i think this is my only solution!, i test below code and seems that do work correctly

inline fun <reified T> listen(): Flow<T> {
    return channel.asFlow().filter { it is T }.map { it as T }
}

can you show me an example of using offer() or send() for my listen method? according to your first suggested method

[bdawg.io]

You can do this to merge the filter and cast into a single operation asFlow().filterIsInstance<T>()

[Gerard Klijs]

Seems like me for an eventbus you want to have some like a server where state persists, and clients without state. Something like https://axoniq.io/