fergusonm

package com.example.launchwhendemo.ui.main

import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.fragment.app.Fragment
import androidx.lifecycle.*
import com.example.launchwhendemo.R
import kotlinx.coroutines.channels.Channel

fergusonm

package com.example.launchwhendemo.ui.main

import android.os.Bundle
import android.util.Log
import android.view.View
import android.widget.Button
import androidx.fragment.app.Fragment
import androidx.lifecycle.ViewModel
import androidx.lifecycle.ViewModelProvider
import androidx.lifecycle.viewModelScope

fergusonm

class MainFragment : Fragment(R.layout.main_fragment) {

    companion object {
        fun newInstance() = MainFragment()
    }

    private lateinit var viewModel: MainViewModel

    override fun onCreate(savedInstanceState: Bundle?) {

fergusonm

fun <T> Flow<T>.collectIn(
    lifecycleOwner: LifecycleOwner,
    minActiveState: Lifecycle.State = Lifecycle.State.STARTED,
    action: suspend (T) -> Unit
): Job = lifecycleOwner.lifecycleScope.launch {
    flowWithLifecycle(lifecycleOwner.lifecycle, minActiveState).collect(action)
}

fergusonm

viewModel.events
    .onEach {
        // can get cancelled when the lifecycle state falls below min
    }
    .flowWithLifecycle(lifecycle = viewLifecycleOwner.lifecycle, minActiveState = Lifecycle.State.STARTED)
    .onEach {
        // Do things
    }
    .launchIn(viewLifecycleOwner.lifecycleScope)

fergusonm

inline fun <reified T> Flow<T>.observeWithLifecycle(
        lifecycleOwner: LifecycleOwner,
        minActiveState: Lifecycle.State = Lifecycle.State.STARTED,
        noinline action: suspend (T) -> Unit
): Job = lifecycleOwner.lifecycleScope.launch {
    flowWithLifecycle(lifecycleOwner.lifecycle, minActiveState).collect(action)
}

inline fun <reified T> Flow<T>.observeWithLifecycle(
        fragment: Fragment,

fergusonm

viewModel.events
    .observeWithLifecycle(fragment = this, minActiveState = Lifecycle.State.RESUMED) {
        // do things
    }

viewModel.events
    .observeWithLifecycle(lifecycleOwner = viewLifecycleOwner, minActiveState = Lifecycle.State.RESUMED) {
        // do things
    }

fergusonm

class MyViewMode: ViewModel() {
    data class ViewState(
        val someUIProperty: String = "",
        val someOtherUIProperty: Int = 1,
    )
    
    private val _viewState = MutableStateFlow<ViewState>(ViewState())
    val viewState = _viewState.asStateFlow()
}

fergusonm

// In your view/fragment
viewLifecycleOwner.lifecycleScope.launch {
    viewModel.viewState
        .flowWithLifecycle(viewLifecycleOwner.lifecycle, Lifecycle.State.STARTED)
        .collect { 
            // do something with the UI updates
        }
}

fergusonm

// In your view model
private val _eventChannel = Channel<Event>(Channel.BUFFERED)
val events = _eventChannel.receiveAsFlow()