```LazyColumn { items(postList) { Post...

# compose

[Ink]

LazyColumn {
    items(postList) {
        Post(
            onPostClick = { post -> PostDetailsScreen() },
            it
        )
    }
}

I display list with post. When I select post I want to open new @Composable view with post's details. Now I get error:
@Composable invocations can only happen from the context of a @Composable function.
Why?

[Filip Wiesner]

Because onPostClick parameter is probably not @Composable so like the error says, you are not calling it from Composable context.
But don't get me wrong, it shouldn't be composable. You need to change your thinking about declarative UI.
If PostDetailsScreen is another screen than you don't probably want to display it inside your LazyColumn item (because you are calling it inside it now). What you are probably trying to do is to do some kind of navigation and for that you could use the androidx navigation library or just hack something yourself.

[Ink]

That's 100% true. My solution:
• Create enum with destination screens

enum class Destination{
    PostDetails
    AuthorDetails
}

• Create NavController

val mainNavController = rememberNavController()

• Handle opening screens in navController

@Composable
fun MainNavigationHost(mainNavController: NavController) {
    NavHost(
        navController = mainNavController as NavHostController,
        startDestination = "default"
    ) {
        composable("default") {}
        composable(Destination.PostDetails.name) {
            PostDetailsScreen(postList[2])
        } 
        composable(Destination.AuthorDetails.name) {
            AuthorDetailsScreen()
        }
    }
}

• Put destination screen to navController

LazyColumn {
    items(postList) {
        Post(
            onPostClick = { mainNavController.navigate(Destination.PostDetails.name) },
            it
        )
    }
}

[Ian Lake]

Note the specific recommendation to not pass your navController into your screens, but instead pass down a lambda: https://developer.android.com/jetpack/compose/navigation#testing

This means your screen is much easier to test in isolation and you keep all of your navigation code in one place instead of leaking your routes, arguments, etc. into your other classes