I have a flow mapping like this: ```var selectedGr...

# compose

[Justin Xu]

I have a flow mapping like this:

var selectedGroup: MutableStateFlow<Group?> = MutableStateFlow(null)
...
private val _userInfosFlow = APIServer.getAllUserInfosAsFlow()
val userInfos: StateFlow<List<UserInfo>> =
    _userInfosFlow.map { userInfos ->
        selectedGroup.value?.let { group ->
            userInfos.filter { userInfo ->
                userInfo.groupId == group.getId()
            }
        } ?: emptyList()
    }

Where _userInfosFlow just gets a list of all UserInfo objects from database, and userInfos is a StateFlow that filters that list to only contain UserInfo's belonging to the current selectedGroup. Since I use .map, I believe the userInfos flow will emit only when _userInfosFlow emits. However, I also want userInfos to emit when selectedGroup.value changes, since that means that a new group is selected, and userInfos should logically update to now contain UserInfo's from the newly selected group. What is the best way to trigger this emission? Or is there just a better way to do this altogether

[Albert Chang]

This is a #coroutines question.
You can use `combine`:

combine(_userInfosFlow, selectedGroup) { userInfos, group ->
    ...
}