<@UHAJKUSTU> Hi. Can I ask about transfer some eve...

# mvikotlin

[Egor K.]

@Arkadii Ivanov
Hi. Can I ask about transfer some events from one feature to another?
For example: by clicking on the back button on screen A, I gonna go to the previous screen B, and the item list should be updated on screen B. Something like eventbus comes to mind. Create some SharedFlow, emit event from Store A and collect it in Store B. But where I should collect it? In custom Bootstrapper in Store B?
How do you recommend implementing such logic?

[Arkadii Ivanov]

Hi. I suppose you have a Store in the screen B. You can have an Intent like StoreB.Refresh, which you can send when the screen B is e.g. resumed. Or you can send Intent.Refresh when you navigate from A to B, e.g. in a parent Fragment/Controller/Whatever.

[Egor K.]

Okay, but how will FragmentA know that I clicked on FragmentB back button?
(sorry for my English in advance)

I see this situation like this:
1. I’m on the FragmentB.
2. I’m clicked on the back button and send the Intent to the StoreB.
3. I caught the Intent.Back in StoreB (in Executer) and … (by my version) I should emit some BusEvent.
4. Then I need to catch the BusEvent in the StoreA. Because I wanna say: “Hey, FragmentA, I gonna go back to you from FragmentB, please know about it and update my item list”.
5. So to implement №4 logic, I should subscribe to BusEvents in StoreB. If I using SharedFlow, I should call collect() method.
Something like this…) please correct me if need to.

[Arkadii Ivanov]

Your FragmentA can have outputs, so you can emit something like Output.Finished. The output should be handled by the parent Fragment, which actually does navigation. Check out this example: https://github.com/arkivanov/MVIKotlin/blob/85b6bc2343bedea4242817796728eb8f3ceb71ee/sample/todo-app-android/src/main/java/com/arkivanov/mvikotlin/sample/todo/android/root/RootFragment.kt#L62

[Egor K.]

thx! I’ll check it :)

[Arkadii Ivanov]

So you can emit Output.Finished directly from the back button click listener, or if you need additional logic in your StoreB, then you can bind it's Labels to Output.

[Egor K.]

sounds rock)