I'm getting another arcane build error. Is Android...

# getting-started

[Chris B]

I'm getting another arcane build error. Is Android Studio actually stable? It feels incredibly fragile to me.

[Chris B]

The error is Type 'androidx.compose.runtime.State<puzzles.PuzzlesState>' has no method 'getValue(Nothing?, KProperty0<*>)', so it cannot serve as a delegate.

[hfhbd]

Compiler errors are unrelated to the IDE.
Did you add the getValue import?

[Chris B]

What getValue import?

[Chris B]

I was following https://www.jetbrains.com/help/kotlin-multiplatform-dev/compose-viewmodel.html#using-viewmodel-in-common-code

[hfhbd]

import androidx.compose.runtime.getValue
import androidx.compose.runtime.setValue

[Chris B]

Why do I need to import a function which isn't referenced in my code?

[hfhbd]

getValue/setValue is the function behind the delegate called by by

[hfhbd]

If you only use val, you only need the getValue, otherwise you need the write method (setValue) too

[hfhbd]

And for some reasons these functions are not member functions but extensions requiring an import

[Chris B]

I wish this were explained somewhere.

[Chris B]

I thought I had the ViewModels working, but I restructured some of my code and everything broke. Now components aren't updating and they're reverting to old versions of the state.

[Chris B]

None of it seems well-documented and it's incredibly hard to figure out what's talking about Android-only code vs. multiplatform.

[Chris B]

And most of the instructions I found conflict with one another.

[hfhbd]

Yeah, the documentation could be improved. The best documentation is the Android one, so I suggest, read the Android documentation first, write some Android apps and then convert it to desktop.

[Chris B]

Thanks for helping out. It's just really frustrating to follow what's supposed to be a step-by-step tutorial and run into confusing and arcane errors.

[Chris B]

In https://developer.android.com/codelabs/basic-android-kotlin-compose-viewmodel-and-state#5, it has the following code:

import androidx.lifecycle.viewmodel.compose.viewModel

@Composable
fun GameScreen(
   gameViewModel: GameViewModel = viewModel()
) {
   // ...
}

[Chris B]

But there is no viewModel function. The import fails.

[Chris B]

How is this broken, and can I get the ViewModel instance from anywhere or is it important to create it in the argument list?

[Ramitsuri007]

I believe that function comes from this artifact implementation("androidx.lifecycle:lifecycle-viewmodel-compose:2.6.1") which needs to be included in step 5

https://developer.android.com/codelabs/basic-android-kotlin-compose-viewmodel-and-state#4

[Chris B]

I have androidx-lifecycle = { group = "androidx.lifecycle", name="lifecycle-viewmodel-compose", version.ref = "androidx-lifecycle" } defined in my build, at version 2.8.4