Is there a way to use `retry` based on a valid emitted value and not based on exception occuring? M...

# coroutines

[niqo01]

Is there a way to use retry based on a valid emitted value and not based on exception occuring?
My emitted value looks like this

public sealed class BillingClientState{
        public object Initializing: BillingClientState()
        public data class Available(val client: BillingClient): BillingClientState()
        public object Unavailable: BillingClientState()
        public object Disconnected: BillingClientState()
    }

I want rety when Disconnected is triggered

[ephemient]

one option: .onEach { check(it !is Disconnected) }.retry(...)

[ephemient]

probably could build something less throw-y worth .transformWhile

[ephemient]

fun <T> Flow<T>.retryWhen(predicate: suspend (T) -> Boolean) = transformWhile { if (predicate(it)) { emitAll(retryWhen(predicate)); false } else { emit(it); true } }

[ephemient]

untested, and of course you'd likely want some way to limit attempts, but that's an idea at least

[Arun Joseph]

Any idea how would limit attempts? I tried using a recursive retryWhen but did not work.

[ephemient]

should work if you add a counter and guard,

fun <T> Flow<T>.retryWhen(retries: Int = Int.MAX_VALUE, predicate: suspend (T) -> Boolean): Flow<T> {
    require(retries >= 0)
    return if (retries == 0) this else transformWhile {
        if (predicate(it)) {
            emitAll(retryWhen(retries - 1, predicate))
            false
        } else {
            emit(it)
            true
        }
    }
}

[Arun Joseph]

Thanks a lot for a quick reply, will try this.