MVI arxitekturasida saqlash kerak bo'lmagan…

MVI'da bir martaba bo'lib o'tadigan voqealarni (masalan, toast ko'rsatish, navigatsiya) boshqarish uchun, ular View yoki holatni qayta yaratishdan o'tib ketmasligi uchun, turli yondashuvlar qo'llaniladi:

Side Effects (SingleLiveEvent / Channels):

ViewModel'dan View'ga voqealarni yuborish uchun maxsus mexanizm. SingleLiveEvent (eski loyihalarda yoki androidx.lifecycle:lifecycle-livedata-ktx kabi kutubxonalar), yoki Flow'dan Channel (zamonaviy loyihalarda). Ular voqea faqat bir marta iste'mol qilinishini kafolatlaydi.

// Flow va Channel bilan ViewModel
import kotlinx.coroutines.channels.Channel
import kotlinx.coroutines.flow.receiveAsFlow
import androidx.lifecycle.ViewModel
import androidx.lifecycle.viewModelScope
import kotlinx.coroutines.launch

class MyViewModel : ViewModel() {

    private val _sideEffect = Channel<SideEffect>(Channel.BUFFERED)
    val sideEffect = _sideEffect.receiveAsFlow()

    fun doSomething() {
        // Biznes logika...
        viewModelScope.launch {
            _sideEffect.send(SideEffect.ShowToast("Operatsiya muvaffaqiyatli bajarildi!"))
        }
    }
}

sealed class SideEffect {
    data class ShowToast(val message: String) : SideEffect()
    object NavigateNext : SideEffect()
}

// View'da (Fragment/Activity) SideEffect'ni kuzatamiz
import androidx.fragment.app.Fragment
import androidx.lifecycle.lifecycleScope
import kotlinx.coroutines.flow.collect
import kotlinx.coroutines.launch

class MyFragment : Fragment() {

    private val viewModel: MyViewModel by viewModels()

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        viewLifecycleOwner.lifecycleScope.launch {
            viewModel.sideEffect.collect { effect ->
                when (effect) {
                    is SideEffect.ShowToast -> showToast(effect.message)
                    SideEffect.NavigateNext -> navigateToNextScreen()
                }
            }
        }
    }

    private fun showToast(message: String) {
        // Toastni ko'rsatish
    }

    private fun navigateToNextScreen() {
        // Navigatsiya
    }
}

Yagona foydalanish voqealari holatda:

Kamroq tavsiya etilgan, lekin ba'zan oddiy holatlarda qo'llaniladi. UiStatega, yagona foydalanish voqeasining mavjudligini ko'rsatadigan flag yoki maydon qo'shiladi. Vaqea ishlov berilgach, View yangi Intent yuboradi, bu flag yoki maydonni holatda reset qilish uchun. Bu logikani murakkablashtirishi mumkin va noto'g'ri boshqarilsa yoki View qayta yaratilsa, takrorlanishiga olib kelishi mumkin.

// Yagona flag bilan holat misoli
data class MyUiState(
    val data: List<Item> = emptyList(),
    val isLoading: Boolean = false,
    val showSuccessToast: Boolean = false // Yagona voqea uchun flag
)

// ViewModel'da muvaffaqiyatli operatsiyadan so'ng
fun processSuccess() {
    _uiState.update { it.copy(showSuccessToast = true) }
}

// View'da showSuccessToast = true bo'lsa
if (state.showSuccessToast) {
    showToast("Muvaffaqiyat!")
    // Muhim: flagni reset qilish uchun Intent yuborish
    viewModel.onToastShown()
}

// ViewModel'da flagni reset qilish
fun onToastShown() {
    _uiState.update { it.copy(showSuccessToast = false) }
}

Zamonaviy Androidda Flow va MVI bilan eng tavsiya etilgan yondashuv — Channel orqali Side Effects foydalanish. Bu toza, xavfsiz va oldindan aytib bo'ladigan yagona voqealar uchun yechimdir.

MVI arxitekturasida saqlash kerak bo'lmagan voqealarni qanday boshqarish mumkin?