Is there a way to control class visibility, so the...

# multiplatform

[christian.steffensen]

Is there a way to control class visibility, so they can only be used within the shared code and not visible at all on the platforms themselves?

[Mohammed Alramlawi]

If you are following a modularization architecture, then I think you can define it as an internal class!

[christian.steffensen]

That was my thought as well, I just can’t quite wrap my head around it. It seems that whenever I try to use an internal class in a public class, then I get

public' function exposes its 'internal' parameter type

But it’s probably just missing knowledge on my end about modules and internal visibility - and not KMP related 🙂

[Mohammed Alramlawi]

You're right. This error occurs because public APIs can't expose internal types.

To resolve this, ensure that all functions and classes using the internal class are also internal or private. Alternatively, use a public interface:

// Internal class
internal class InternalClass {
    fun doSomething() {}
}

// Public interface
interface PublicInterface {
    fun doSomething()
}

// Public class using the internal class
public class PublicClass : PublicInterface {
    private val internalInstance = InternalClass()

    override fun doSomething() {
        internalInstance.doSomething()
    }
}

[Mohammed Alramlawi]

This keeps InternalClass hidden while exposing PublicClass.
Hope this helps!

[christian.steffensen]

That’s interesting, I’ll look into it, thanks!

[Mohammed Alramlawi]

You're welcome! 🙂

[christian.steffensen]

In my case, I actually just had to mark the constructor as internal as well, that was the only place it was causing problems 🙂