CODEWITHSUNDEEP
androidkotlinandroid-jetpack-composekotlin-coroutines
HavanaSun
HavanaSun

Reputation: 956

Jetpack Compose - mutableStateOf() not updating

I got a ScreenState data class in my ViewModel:

data class ScreenState(
    var isLoading: Boolean = true,
    val items: List<Posts> = emptyList()
)

and a mutableStateof:

private val _homeScreenState = mutableStateOf(ScreenState())
val homeScreenState: State<ScreenState> = _homeScreenState

Updating the isLoading property works fine, the change gets send to my UI:

_homeScreenState.value = _homeScreenState.value.copy(isLoading = true)

But updating an item inside my List<Posts> does not work. Here is how I try to do it:

val updatedList = homeScreenState.value.items.toMutableList()
val index = updatedList.indexOfFirst { it.id == passedPost.id }
updatedList[index] = updatedList[index].copy(isLiked = true)
_homeScreenState.value = _homeScreenState.value.copy(items = updatedList)

I'm trying to update the isLiked Boolean inside my Post data class and show the change in the UI. I do understand, that this is a normal behaviour and that the mutableStateOf does not update because the ScreenState itself does not update but the item inside the List<Post> of the ScreenState.

The problem is that I don't know how to trigger the UI to update.

EDIT This is my Post Data Class:

data class Post(
    val id: Int,
    val name: String, 
    val description: String, 
    val isLiked: Boolean = false,
)

Upvotes: 3

Views: 4483

Answers (1)

Remo
Remo

Reputation: 101

data class Post(
    val id: Int,
    val name: String,
    val description: String,
    val isLiked: MutableState<Boolean> = mutableStateOf(false),
)

or

class Post(
    val id: Int,
    val name: String,
    val description: String,
    isLiked: Boolean = false,
){

    val isLiked by mutableStateOf(isLiked)

}

Upvotes: 0

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