Debouncing my Flow isn't working as I expected. Fe...

# getting-started

[Colton Idle]

Debouncing my Flow isn't working as I expected. Feel like I'm missing something basic here:

13:50:11.748  E  emitting 13
13:50:11.883  E  emitting 493
13:50:13.755  E  dispatching 493
13:50:14.129  E  emitting 493
13:50:14.272  E  emitting 493
13:50:14.345  E  emitting 493
13:50:14.732  E  emitting 493
13:50:15.012  E  emitting 493
13:50:15.211  E  emitting 493

I would expect two dispatches in my logs. Code in thread

[Colton Idle]

viewModelScope.launch {
    Log.e("LOG", "emitting ${items.flatMap { it.items }.size}")
    myStateFlow.emit(items)
}

[Colton Idle]

viewModelScope.launch {
    myStateFlow.debounce(2_000).collectLatest { dispatchItems(it) }
}

[Colton Idle]

fun dispatchItems(items: Set<Items<Person>>) {
        Log.e("LOG", "dispatching ${items.flatMap { it.items }.size}")
...

[ephemient]

why? that all seems expected as per the docs

[ephemient]

https://kotlinlang.org/api/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines.flow/debounce.html

Note that the resulting flow does not emit anything as long as the original flow emits items faster than every timeoutMillis milliseconds.

[ephemient]

looks like the only gap in your timings longer than that is where the dispatch happened

[Colton Idle]

hm. i guess something isn't clicking yet. it doesn't seem weird to you that there's no second dispatch about 2 seconds after the first (and only) dispatch?

[Colton Idle]

Changed it to a SharedFlow and now it seems to be working as I expected?

[CLOVIS]

What did you expect?

[Colton Idle]

Pretty much just thinking there'd be one last dispatch event

like so

135011.748 E emitting 13
135011.883 E emitting 493
135013.755 E dispatching 493
135014.129 E emitting 493
135014.272 E emitting 493
135014.345 E emitting 493
135014.732 E emitting 493
135015.012 E emitting 493
135015.211 E emitting 493
135015.211 E dispatching 493

[ephemient]

how would it know not to wait for events after the last one?

[Colton Idle]

i guess i dont know, but i could have sworn i was using debounce in rxjava this way. but maybe i was using rx wrong. dang. i wonder the best way to get this done is then lol