Hi guys. I have a question over the example given ...

# compose

[Alex Bieliaiev]

Hi guys. I have a question over the example given here - https://developer.android.com/jetpack/compose/lifecycle#composition-anatomy. Based on https://medium.com/androiddevelopers/under-the-hood-of-jetpack-compose-part-2-of-2-37b2c20c6cdd my understanding was that LoginInput is supposed to be recomposed, because its position in the slot table is different. That seems not to be the case, according to the docs. So what am I missing here? Thank you in advance.

[Zach Klippenstein (he/him) [MOD]]

Not sure what you mean – are you asking if LoginInput would be recomposed if LoginScreen were called with a different value for showError?

[Alex Bieliaiev]

Yes, my question is about LoginInput - docs state that it won't be recomposed. And this is a bit confusing for me - I though that a composable, which changes position in the slot table, is re-composed.

[Zach Klippenstein (he/him) [MOD]]

I believe that the compose runtime is smart enough to realize that it just “moves” around, and because it doesn’t require a recomposition for any other reason (it takes no params), it won’t recompose it just because there’s another group being added/removed before it.

[Alex Bieliaiev]

Yes, I agree, that is exactly what docs say, but my question is more about "how does that work under the hood".

[Alex Bieliaiev]

That question arises from the next section of the same doc - https://developer.android.com/jetpack/compose/lifecycle#add-info-smart-recomposition. In case of multiple invocations of the same composable from the same call site the compose runtime is not that smart and requires extra assistance.

[Zach Klippenstein (he/him) [MOD]]

Chuck recently gave another explanation of this, it might answer your question?

[Alex Bieliaiev]

Yes, it might, thank you, I'll read it.

[Alex Bieliaiev]

That's a great explanation, thank you, @Chuck Jazdzewski [G]. I still have a small question, though. Docs mention, that execution order might be a part of a Group key. Is that the case only when the same composable is called multiple times from the same call site or there are other scenarios?