Event when the slot changes from fallback to passed content

[icalvin102]

As the title says: I'm searching for a event that triggers when the slot changes from fallback to passed content and vice versa.

https://svelte.dev/repl/d4c9910e42b045a6aabdd07eadbe8cb9?version=3.24.1

So I tried to build a hacky workaround (see link above) to pass a prop from a fallback component (onMount/dismount) to
the parent component with the slot.
But the problem with this script is that an {#if} block is seen as non-empty by the slot even though the condition is false
and no output is passed to the slot.

Is this by design or is this a bug?

And is there a way to get a event and/or state of a slot?

Thanks :)

[Conduitry]

You should be able to use #4602 which is a recently added feature that we haven't gotten around to documenting yet.

[icalvin102]

Thank you for your response. This is in theory what I was looking for.
However it lacks some important details for me. I illustrated the problem and feature request more in detail in #5312