Why onEach instead of collect {}

[mobilekosmos]

    lifecycleScope.launch {
        lifecycle.repeatOnLifecycle(Lifecycle.State.STARTED) {
            viewModel.uiState
                .onEach {
                    uiState = it
                }
                .collect()
        }
    }

I'm trying to learn best practices and I'm not sure why you are using in the MainActivity .onEach instead of just simply using collect {} directly, just personal preference?

[vamsi3]

I'm curious about this too.

I did find a session from the Android Dev Summit 2021 where they mention the use of .collect {...}.

---

Also, I stumbled upon this discussion post while wondering why we don't use .collectLatest {...} itself here, i.e.,

lifecycleScope.launch {
    lifecycle.repeatOnLifecycle(Lifecycle.State.STARTED) {
        viewModel.uiState
            .collectLatest { uiState = it }
    }
}

Hoping for anyone with more experience in Kotlin Flows to comment on whether this is a valid (and better) code.

[ParkJong-Hun]

I think it's written that way when he considers a lot of maintenance of functions.
Because no mapping method can come after collect.

[anhtuannd]

@ParkJong-Hun
Agree with you, onEach is triggered before value is emitted downstream. So, it will be applied to all consumers.
We can also add catch() to handle exception during transmitted.