Hello again wave This might be a silly question but I m havi

Question

Hello again wave This might be a silly question but I m having a hard time trying to understand Does the recomposition for a `State` only occurs when inside an action from a ` Composable` For example ```var state by rememberSaveable mutableStateOf StateA when state StateA gt if condition state = StateB else state = StateC This does not trigger StateB gt Button onClick = state = StateD Text Click me This works fine when clicked ``` I m trying to do some condition check before showing UI for the user and tried using `State` Any thoughts Thanks a lot heart

Zach Klippenstein (he/him) [MOD] · Answer

I thought reading a state and then writing to it later in the same composition caused a compiler error but even if it doesn t it s still a code smell for other reasons This sort of code is hard to read because it s not a simple mapping of state to UI things go backwards there are kind of multiple sources of truth and I think it can also cause flicker because that recomposition might not happen until the next frame although i m not actually sure what will happen

Zach Klippenstein (he/him) [MOD] · Answer

You could for example do something like this instead ```var primaryState by rememberSaveable mutableStateOf StateA val secondaryState by remember derivedStateOf if condition StateB else StateC ``` And then it would make sense for `StateA` and `StateB` `StateC` to not share a parent type

escodro · Answer

Thanks a lot Zach I ll try this solution on Monday Have a great weekend heart

escodro · Answer

Hello again Zach Thanks for your insight Thanks to that I was able to come with a solution closer to your recommendation blush To give more context I m trying to handle a Dynamic Feature installation which may show a couple of `AlertDialogs` to inform the user about the download process The `State` are ```RequestDownload gt show a dialog to the user Downloading gt show a dialog with progress FeatureReady gt open the DFM``` Previously I had another `State` called `FeatureVerification` which checked if the feature is already installed so it could jump to `FeatureReady` state Based on your comment I updated to the following code ```val isFeatureReady = isFeatureInstalled featureName = featureName val initialState = if isFeatureReady FeatureReady else RequestDownload var state by rememberSaveable mutableStateOf initialState when state RequestDownload gt Downloading gt FeatureReady gt ``` What do you think about it blush

Zach Klippenstein (he/him) [MOD] · Answer

Can `isFeatureInstalled` change the value that it returns over time If it can this code could be tricky to reason about

escodro · Answer

Yes It could change Is it better based on your previous suggestion ```val isFeatureReady = isFeatureInstalled featureName = featureName val initialState = remember derivedStateOf if isFeatureReady FeatureReady else RequestDownload var state by rememberSaveable mutableStateOf initialState value when state RequestDownload gt Downloading gt FeatureReady gt ```

Zach Klippenstein (he/him) [MOD] · Answer

Nope because `state` will still only read the value when it s initialized and not even then if it s being restored

escodro · Answer

Do you have any suggestion in this case

Zach Klippenstein (he/him) [MOD] · Answer

Well first this seems like logic that should probably live in your view model not your composable

Zach Klippenstein (he/him) [MOD] · Answer

But the same logic applies wherever you do it Track isFeatureReady so you know when it changes and when that happens then update the mutable state

escodro · Answer

I see The idea behind this Composable is to act like a library you pass the DFM name and the Compsable shows the dialog and handles the UI UX Thanks a lot Zach I will try to investigate other solutions

Dmitrii Smirnov · Answer

You probably should better move logic to ViewModel or something and only show state in your Composable function