Hello! Maybe somebody could help understand why `r...

# compose

[Dmitry Motyl]

Hello!
Maybe somebody could help understand why rememberSaveable doesn’t keep state
And what I need to do to fix that

Untitled.kt

[Alex Vanyo]

It looks like you might be looking for SaveableStateHolder?

[Alireza Kherazani]

That's actually happens because of using if statement to show composable ... when u use if and use a condition to show some different or multiple composables , the false part will be removed from the composition tree and even remember will be destroyed ... so whenever the condition turns true , the composable go for redraw and recreate not for recompose. At last u have to find another way to show and switch between views like navigations. or if you still want to use conditions ... you can save your states in a viewmodel .. Hope it helps😉

[Dmitry Motyl]

@Alex Vanyo yes, it is, thank you 😃

[Dmitry Motyl]

@Alireza Kherazani I was asking about rememberSaveable not just remember

[Stylianos Gakis]

What Alireza mentions absolutely applies to rememberSaveable too. Give it a read again, you might understand what they're trying to convey.

[Alireza Kherazani]

@Dmitry Motyl That doesn't make any difference ... @Stylianos Gakis Correct , thank you so much 👍

[Dmitry Motyl]

Guys, the question was about rememberSaveable and what is missing for it to work.
And @Alex Vanyo helped very well with it.
But thank you for your explanations

[Alireza Kherazani]

@Dmitry Motyl That would be so great if you share that with us too plz

[Dmitry Motyl]

this article should explain
https://medium.com/@agaber929/mastering-state-management-in-jetpack-compose-remember-remembersaveable-and-807eeecfc023

[Kiron James]

Hi All

I have a smiliar issue with preserving state. I am using a Lazycolumn in my app and having issues with saving state while scrolling across.


I am trying to save a selection from a group of radio buttons and this is iterative for each set of data. I tried using the following but it retains only what was on display last and loses the rest of the selection

var (selectedOption, onOptionSelected) = rememberSaveable { mutableStateOf(radioOptions[0]) }


Screenshot below comparison after my selection and after a configuration change (Portrait to Lanscape and back)



I tried using rememberSaveableStateHolder() still same issue. Not sure if my usage is correct. Is there anything I am doing wrong?


var saveableStateHolder = rememberSaveableStateHolder()

saveableStateHolder.SaveableStateProvider(radioOptions) {

ChoiceComposable(choice, radioOptions)

}

Following is my code


LazyColumn(
modifier = Modifier
.padding(horizontal = 20.dp, vertical = 30.dp)
.background(Color.White)
) {

items(multiplechoice) {
choice ->

val radioOptions = listOf(choice.choice1,choice.choice2,choice.choice3,choice.choice4,choice.choice5)

QAPage(choice, radioOptions)

}

}
}



@Composable
fun QAPage(choice: QandA,
radioOptions: List<String>
) {


// saving state across each set while scrolling
var saveableStateHolder = rememberSaveableStateHolder()

saveableStateHolder.SaveableStateProvider(radioOptions) {

ChoiceComposable(choice, radioOptions)

}

}

@Composable
fun ChoiceComposable(choice: QandA,
radioOptions: List<String>){

var (selectedOption, onOptionSelected) = rememberSaveable { mutableStateOf(radioOptions[0]) }

Row(
Modifier.rowStyle()
) {
Text(
text = choice.question,
fontSize = 15.sp,
fontWeight = FontWeight.Bold,
modifier = Modifier
.weight(1f)
)
}

radioOptions.forEach { qachoice ->
Column(modifier = Modifier.selectableGroup()) {
// Selection happens in the row section so disabling on click at the radiobutton level
Row(
Modifier.rowStyle()
.selectable(
selected = (qachoice == selectedOption),
onClick = { onOptionSelected(qachoice) },
role = Role.RadioButton
)
) {
Text(
text = qachoice,
fontSize = 7.sp,
modifier = Modifier
.weight(.50f)
.fillMaxHeight()
)
RadioButton(
selected = (qachoice == selectedOption),
onClick = null,
Modifier.radioStyle(),
colors = radiocolors,
)
}
Spacer(
modifier = Modifier
.height(10.dp)
)
}
}

}

[gildor]

@Kiron James please, use thread