When will it be possible to combine @Composable an...

# compose

[Roar Gronmo]

When will it be possible to combine @Composable and Room ?

I think its crucial that those two features can coexist.

RG

[Adam Powell]

Yes. Room can give you back both `Flow`s and `LiveData`s of query results, and compose can subscribe to those and render the results as they change.

[Adam Powell]

You can do it today with some integration glue

[Adam Powell]

Flow is a bit of a challenge at the moment due to some incompatibilities between the version of the IR compiler the latest compose plugin is using and generating suspending code, but some clever module separation can work around it for now. We're pretty anxious to see these bugs get fixed soon

[Adam Powell]

LiveData is a little bit easier, let me see if I can dig up the snippet to use as an observe() effect for it

[Adam Powell]

there it is:

fun <T> observe(data: LiveData<T>) = effectOf<T?> {
    val result = +state<T?> { data.value }
    val observer = +memo { Observer<T> { result.value = it } }

    +onCommit(data) {
        data.observeForever(observer)
        onDispose { data.removeObserver(observer) }
    }

    result.value
}

[Adam Powell]

usage is:

val currentValue = +observe(myLiveData)

[Adam Powell]

you'll get a recomposition each time the LiveData value changes, and the LiveData will have an active observer for the duration of that composition

[Adam Powell]

which is to say, the `LiveData`s returned by room queries will continue updating until that part of your compose UI goes away

[Roar Gronmo]

Thanx alot !!! @Adam Powell, I'll test this on Monday...

[Ash]

Just what I needed! Have been working on this over the weekend 🙏🏽

[Andrew Kelly]

@Roar Gronmo I used the +observe snippet of code successfully in a few talks I gave on Compose recently, just to show something more heavyweight compared to the existing @Model observable examples.

[Ash]

@Andrew Kelly Do you have a link to the talks?

[Andrew Kelly]

I did them at DevFest Melbourne, DevFest Sydney and DevFest Cape Town. I haven’t seen any uploads yet, I imagine they’re still processing them all.