<https://github.com/JakeWharton/SdkSearch/blob/mas...

# coroutines

[ursus]

https://github.com/JakeWharton/SdkSearch/blob/master/sync/src/commonMain/kotlin/com/jakewharton/sdksearch/sync/ItemSynchronizer.kt

private val _state = ConflatedBroadcastChannel<SyncStatus>()
   val state: ReceiveChannel<SyncStatus> get() = _state.openSubscription()

  fun forceSync() {
    _state.offer(SyncStatus.SYNC)
    GlobalScope.launch {
      val result = if (load()) SyncStatus.IDLE else SyncStatus.FAILED
      _state.offer(result)
    }
  }

how would you handle this if forceSync() took an parameter? Channel per params would be needed @gildor

[gildor]

But what exactly it should sync?

[gildor]

In this example it just reads current status again

[ursus]

Im imagining how to expand this, if forceSync took parameter, which would narrow down the sync operation for example

[ursus]

which means you could have mutiple syncs (per param )going on at the same time, which implies channel per running sync

[gildor]

if it’s kinda continue of discussiion with postMessageOBservable, than this forceSync with param just would clear cached value

[gildor]

But again, semantics of your code is different, you just post value and do not await other values

[ursus]

..would clear cached value? I dont follow

[gildor]

if you need stream of events (like in this case), you need some different way

[gildor]

again, I’m just guessing what you want to achive

[ursus]

channel is a stream of events, isnt it?

[gildor]

semantics of this class from SdkSearch is pretty clear for me

[gildor]

yes, channeels is a stream of events

[ursus]

im trying to achieve forceSync(target: Target) {}

[ursus]

instead of forceSync()

[ursus]

where Target is for example Foo, Bar tables, whatever

[ursus]

so sync of Foo and sync of Bar can run in parallel, and you need states of both in various parts of ui

[ursus]

tldr; you cannot have single channel for this, I think

[gildor]

Could you show full example of such class

[ursus]

I dont have an example, im just imagining this Jake's class how would one extend it, since now forceSync presumably only syncs everything, therefore no param is needed and single _state Channel is sufficient

[gildor]

this class exposes one channel of events

[ursus]

yes, which would not do if we were to parametrize the forceSync function

[gildor]

if you need abstraction that exposes different channel depending on Target it will be very different, so forceSync is not your only problem in this case

[ursus]

yes, possibly

[gildor]

definitely

[ursus]

so..how? map of channels?

[gildor]

I don’t know, depending on your case and semantics which you want to have

[gildor]

there is no universal solution

[ursus]

well Id like semantincs like in the sample but be able to add params to forceSync

[gildor]

If we talking about this example, you can build some manager of ItemSynchronizer that create new ItemSynchronizer for each Target

[ursus]

true, buts thats just moving the map from synchronizer to manager, right?

[ursus]

i.e. map of channels becomes map of itemsynchronizers

[gildor]

well Id like semantincs like in the sample but be able to add params to forceSync

It’s not the only thing what you need, I believe you also need some sort of parameterized state which require completely different implementation

[ursus]

yea I thought about parametrizing State like State(target) and then filter in the callsite

[ursus]

but, that would have issue of replays,i.e it would only cache last, regardless of target, you'd need cache per target, to not miss stuff

[ursus]

in which case you might awswell have map of channels per target

[ursus]

this all COULD work if Target is exhaustive, like enum

[ursus]

but what if there are more variable params like Int or whatever

[ursus]

@jw maybe?