Does anyone have any tips of wrapping a `LiveData` in a `Flo

Question

Does anyone have any tips of wrapping a `LiveData` in a `Flow` or using flow in instead of Livedata

rkeazor · Answer

they are two different things two different used cases

gildor · Answer

Not sure that those are different

gildor · Answer

There is no official adapter for LiveData lt gt Flow

gildor · Answer

but I believe that we need one

gildor · Answer

but probably instead adding it to Koitlinx coroutines it should be ktx library

gildor · Answer

Probably make sense to create a feature request on Android Issue tracker

gildor · Answer

they already have some coroutines support but only for liveData builder

gildor · Answer

gildor · Answer

In general you can write some adhoc adapter using callbackFlow <https kotlin github io kotlinx coroutines kotlinx coroutines core kotlinx coroutines flow callback flow html>

gildor · Answer

gt using flow in instead of Livedata Using Flow instead of Livedata should be completely fine IMO but some integration from Arch components will not work like data binding for example

Saiedmomen · Answer

Is there something in Flow that can hold the last value like behaviour subject

voben · Answer

I think you may be looking for coroutine channels

gildor · Answer

ConflatedBroadcastChannel is work like that

gildor · Answer

and you can just open Flow subscription to Channel so from user point it will look as Flow

gildor · Answer

also there is proposal to reimplement ConflatedBroadcastChannel on top of Flow <https github com Kotlin kotlinx coroutines issues 1082>

rkeazor · Answer

They are different in a sense that one is for cold asynchronous streams and the other is just a data holder that can be lifecycle aware

gildor · Answer

Observable data holder and Kotlinx coroutines have own implementation of it ConflatedBroadcastChannel And also Flow is pretty safe in terms of lifecycle In general I agree that the main use case for Flow is different but still can be used for the same as LiveData

jw · Answer

live data is like a last mile thing where errors can t happen

jw · Answer

you really shouldn t use it for anything but if you have to it needs to just be a bridge between the last gap of your presenter controller whatever and your UI

jw · Answer

somewhat related ktx libraries shouldn t depend on coroutines despite the fact that some of the existing ones already do library integrations and ktx are two very different things

rkeazor · Answer

Tell that to viewModelScope lol Well there is always that debate in whether Coroutines should be considered just a different library or a language feature that just happens to be in a different library

jw · Answer

yeah well i don t use view models either so

rkeazor · Answer

Lmaoo yea I remember lol

rkeazor · Answer

But yea everything has there own usecase Corutines are awesome in there own domain Just like rxjava is good in its domain Same for livedata They are all different concepts Nothing needs to replace anything Just choose what fits the need for your codebase lol

gildor · Answer

I agree it shlouldn t be just livedata ktx that provides this Flow adapter but it may be livedata coroutines kts same way as livedata reactivestreams