Hi everyone, I’m exploring the possibility of conn...

# android

[dammy_abayomi]

Hi everyone, I’m exploring the possibility of connecting Coroutine StateFlow 🤝 DataBinding in a similar way as LiveData do. It seems there isn’t a default implementation at the moment that supports it.

I found an example online which seems quite “burdensome” if one needs to implement it for a bigger project https://github.com/STAR-ZERO/sample-stateflow-databinding

Do you use StateFlow 🤝 DataBinding ? How do you connect them?

[flosch]

please don’t. If you have to, you can just use Flow.asLiveData in your binding adapter.

[nrobi]

For convenience I’d use _mutableStateFlow: MutableStateFlow<T> and expose it like liveData: LiveData<T> get = _mutableStateFlow.asLiveData() similar as @flosch suggested

[dammy_abayomi]

Many thanks @flosch and @nrobi

[dammy_abayomi]

I thought there might be a means to call the StateFlow object right from the XML files to regularly get its updated value.

I’d resolve to exposing the object to a LiveData to get that done.
Thanks again. CC: @flosch @nrobi

[Mustafa Ozhan]

Guys how can i do this in XML right away ?
Reason: i want to move everything into kotlin multi platform common module (No Live data)

I tried to add

<import type="androidx.lifecycle.FlowLiveDataConversions" />

and convert stateFlow to live data in xml like this

app:visibility="@{(FlowLiveDataConversions.asLiveData(vm.state.loading))}" />

but having this error

Cannot find a setter for <android.widget.ProgressBar app:visibility> that accepts parameter type 'androidx.lifecycle.LiveData<?>'

[dammy_abayomi]

Visibility (in XML) should be accepting something like View.VISIBLE .GONE...

Not Boolean. So you need to write a condition that if value is true/false, it should use View.GONE or the one you wish (as the case might be)

[Mustafa Ozhan]

Sorry forgot to share, there is a binding adapter for this

@BindingAdapter("visibility")
fun View.visibility(visible: Boolean) {
    visibility = if (visible) {
        bringToFront()
        View.VISIBLE
    } else {
        View.GONE
    }
}

So the problem now it is working with live data

app:visibility="@{vm.state.loadingLiveData}" />

but it gives error when i use stateFlow with asLiveData extension in XML

app:visibility="@{(FlowLiveDataConversions.asLiveData(vm.state.loadingStateDlow))}" />

[flosch]

What I meant was something like:

@BindingAdapter("visibility")
fun View.visibility(visibilityFlow: StateFlow<Boolean>) {
    visibilityFlow.asLiveData(findViewTreeLifecycleOwner()) { visible ->
        visibility = if (visible) {
            bringToFront()
            View.VISIBLE
        } else {
            View.GONE
        }
    }
}