How do you guys handle nullable states. Doesn't stuff like `Text(user?.name ?: "")` make the code ug...

# compose

[Se7eN]

How do you guys handle nullable states. Doesn't stuff like Text(user?.name ?: "") make the code ugly?

[Grigorii Yurkov]

In which cases user can be null?

[Se7eN]

Like while it's being fetched:
val user by viewModel.getUser(userId).collectAsState(initial = null)

[Se7eN]

I thought of having a User() with empty strings as default values but not sure if that's the best way

[Grigorii Yurkov]

I write something like this

if (user == null){
Loading()
} else {
User(user)
}

[Se7eN]

I see but in my case it's a screen where practically user will never be null and there's no Loading state for the screen

[Grigorii Yurkov]

Can you explain why getUser returns Flow?

[Se7eN]

It maps a Flow<List<User>> to a Flow<User>

[Se7eN]

The Flow<List<User>> fetches users from a network. In the home screen I'm displaying that List<User> and when a User item is clicked, I'm navigating to another screen and passing that User 's id. Then I'm loading that user by simply mapping the user list flow.

[Se7eN]

The empty User way seems good for my case:
val user: User by viewModel.getUser(userId).collectAsState(initial = emptyUser())

[Grigorii Yurkov]

Hm I have the similar case. I have `List<userID`> displayed and after clicking I load user by his ID and open UserScreen.

onClick = {
scope.launch {
val user = viewModel.loadUserById(ID)
openUserScreen(user)
}
}

[Se7eN]

Except that you have a Loading state. I sometimes do

user?.let { user ->
    ...
    Text(user.name)
}

but I'm trynna save some indentation here.

[Grigorii Yurkov]

I have no loading state in this case

[Grigorii Yurkov]

Because I load user from database

[Se7eN]

Ah okay I get it you're waiting for the user to load before opening the screen

[Giorgos Neokleous]

How about Text(user?.name.orEmpty())?

[Se7eN]

There's a lot of user stuff to be displayed so it gets ugly quickly:

Text(user?.name.orEmpty())
CoilImage(user?.picture?.large.orEmpty())
// and a lot of other composables

[Jeisson Sáchica]

Maybe you could specify in the composable that user must not be null and check from the caller if the user is null don't show it or show an empty one.

@Composable
fun UserScreen(user: User?) {
  user?.let { UserInfo(it) } ?: EmptyComponent()
}

@Composable
fun UserInfo(user: User) {
  Text(user.name.orEmpty())
  CoilImage(user.picture?.large.orEmpty())
  // and a lot of other composables
}

[Se7eN]

Yeah that looks good too, thanks!