Hi, I'm using `rememberSaveable {}` on a custom cl...

# compose

[adjpd]

Hi, I'm using rememberSaveable {} on a custom class that implements Parcelable. This saves and restores the object on screen rotation perfectly. All the warning messages, however, tell me that this should not work. Can you help me understand the warning messages? And help me understand if I'm doing something wrong? Code and warnings in 🧵

[adjpd]

@Parcelize
class MyState() : Parcelable {
  private var _inputText by mutableStateOf("")
  val inputText by derivedStateOf { _inputText }
  val inputTextChange = { s:String ->
    _inputText = s
  }
}

rememberSaveable { MyState() }

[adjpd]

The primary constructor is empty, no data will be serialized to 'Parcel'

And this x3

Property would not be serialized into a 'Parcel'. Add '@IgnoredOnParcel' annotation to remove the warning

[adjpd]

So, the error message suggest nothing will be serialised. Yet, when I rotate the screen, the state is restored and my UI has the correct text (unlike if I just use remember {})

[Paul Woitaschek]

On config change nothing is really parceled, it's just put in a map and read from it.

[Paul Woitaschek]

You need to kill the process for the parceling to happen

[theapache64]

@Paul Woitaschek So the proper way would be to use a custom Saver ?

[Paul Woitaschek]

Either that or properly implement parcelable

[Paul Woitaschek]

Write the parcel yourself before using the annotation magic to understand how that works and what the compiler plugin is doing