آموزش معماری MVI در اندروید به صورت گام به گام

 
implementation 'android.arch.lifecycle:extensions:1.1.1'
 
implementation 'androidx.lifecycle:lifecycle-viewmodel-ktx:2.2.0'
 
implementation 'androidx.lifecycle:lifecycle-runtime-ktx:2.2.0'
 
implementation 'com.github.bumptech.glide:glide:4.11.0'
 
 
//retrofit
 
implementation 'com.squareup.retrofit2:retrofit:2.8.1'
 
implementation "com.squareup.retrofit2:converter-moshi:2.6.2"
 
 
//Coroutine
 
implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:1.3.6"
 
implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.6"

package com.mindorks.framework.mvi.data.model
 
import com.squareup.moshi.Json
 
data class User(
    @Json(name = "id")
    val id: Int = 0,
    @Json(name = "name")
    val name: String = "",
    @Json(name = "email")
    val email: String = "",
    @Json(name = "avatar")
    val avatar: String = ""
)

package com.mindorks.framework.mvi.data.api
 
import com.mindorks.framework.mvi.data.model.User
 
interface ApiHelper {
 
    suspend fun getUsers(): List<User>
 
}

package com.mindorks.framework.mvi.data.api
 
import retrofit2.Retrofit
import retrofit2.converter.moshi.MoshiConverterFactory
 
object RetrofitBuilder {
 
    private const val BASE_URL = "https://5e510330f2c0d300147c034c.mockapi.io/"
 
    private fun getRetrofit() = Retrofit.Builder()
        .baseUrl(BASE_URL)
        .addConverterFactory(MoshiConverterFactory.create())
        .build()
 
 
    val apiService: ApiService = getRetrofit().create(ApiService::class.java)
 
}

package com.mindorks.framework.mvi.data.api
 
import com.mindorks.framework.mvi.data.model.User
 
class ApiHelperImpl(private val apiService: ApiService) : ApiHelper {
 
    override suspend fun getUsers(): List<User> {
        return apiService.getUsers()
    }
}

package com.mindorks.framework.mvi.data.repository
 
import com.mindorks.framework.mvi.data.api.ApiHelper
 
 
class MainRepository(private val apiHelper: ApiHelper) {
 
    suspend fun getUsers() = apiHelper.getUsers()
 
}

package com.mindorks.framework.mvi.ui.main.adapter
 
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.recyclerview.widget.RecyclerView
import com.bumptech.glide.Glide
import com.mindorks.framework.mvi.R
import com.mindorks.framework.mvi.data.model.User
import kotlinx.android.synthetic.main.item_layout.view.*
 
class MainAdapter(
    private val users: ArrayList<User>
) : RecyclerView.Adapter<MainAdapter.DataViewHolder>() {
 
    class DataViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        fun bind(user: User) {
            itemView.textViewUserName.text = user.name
            itemView.textViewUserEmail.text = user.email
            Glide.with(itemView.imageViewAvatar.context)
                .load(user.avatar)
                .into(itemView.imageViewAvatar)
        }
    }
 
    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) =
        DataViewHolder(
            LayoutInflater.from(parent.context).inflate(
                R.layout.item_layout, parent,
                false
            )
        )
 
    override fun getItemCount(): Int = users.size
 
    override fun onBindViewHolder(holder: DataViewHolder, position: Int) =
        holder.bind(users[position])
 
    fun addData(list: List<User>) {
        users.addAll(list)
    }
 
}

package com.mindorks.framework.mvi.ui.main.viewstate
 
import com.mindorks.framework.mvi.data.model.User
 
sealed class MainState {
 
    object Idle : MainState()
    object Loading : MainState()
    data class Users(val user: List<User>) : MainState()
    data class Error(val error: String?) : MainState()
 
}

package com.mindorks.framework.mvi.ui.main.viewmodel
 
import androidx.lifecycle.ViewModel
import androidx.lifecycle.viewModelScope
import com.mindorks.framework.mvi.data.repository.MainRepository
import com.mindorks.framework.mvi.ui.main.intent.MainIntent
import com.mindorks.framework.mvi.ui.main.viewstate.MainState
import kotlinx.coroutines.ExperimentalCoroutinesApi
import kotlinx.coroutines.channels.Channel
import kotlinx.coroutines.flow.MutableStateFlow
import kotlinx.coroutines.flow.StateFlow
import kotlinx.coroutines.flow.collect
import kotlinx.coroutines.flow.consumeAsFlow
import kotlinx.coroutines.launch
 
@ExperimentalCoroutinesApi
class MainViewModel(
    private val repository: MainRepository
) : ViewModel() {
 
    val userIntent = Channel<MainIntent>(Channel.UNLIMITED)
    private val _state = MutableStateFlow<MainState>(MainState.Idle)
    val state: StateFlow<MainState>
        get() = _state
 
    init {
        handleIntent()
    }
 
    private fun handleIntent() {
        viewModelScope.launch {
            userIntent.consumeAsFlow().collect {
                when (it) {
                    is MainIntent.FetchUser -> fetchUser()
                }
            }
        }
    }
 
    private fun fetchUser() {
        viewModelScope.launch {
            _state.value = MainState.Loading
            _state.value = try {
                MainState.Users(repository.getUsers())
            } catch (e: Exception) {
                MainState.Error(e.localizedMessage)
            }
        }
    }
}

package com.mindorks.framework.mvi.util
 
import androidx.lifecycle.ViewModel
import androidx.lifecycle.ViewModelProvider
import com.mindorks.framework.mvi.data.api.ApiHelper
import com.mindorks.framework.mvi.data.repository.MainRepository
import com.mindorks.framework.mvi.ui.main.viewmodel.MainViewModel
 
class ViewModelFactory(private val apiHelper: ApiHelper) : ViewModelProvider.Factory {
 
    override fun <T : ViewModel?> create(modelClass: Class<T>): T {
        if (modelClass.isAssignableFrom(MainViewModel::class.java)) {
            return MainViewModel(MainRepository(apiHelper)) as T
        }
        throw IllegalArgumentException("Unknown class name")
    }
 
}

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".ui.main.view.MainActivity">
 
    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:visibility="gone" />
 
    <ProgressBar
        android:id="@+id/progressBar"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        android:visibility="gone"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
 
    <Button
        android:id="@+id/buttonFetchUser"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/fetch_user"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
 
</androidx.constraintlayout.widget.ConstraintLayout>

package com.mindorks.framework.mvi.ui.main.view
 
import android.os.Bundle
import android.view.View
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import androidx.lifecycle.ViewModelProviders
import androidx.lifecycle.lifecycleScope
import androidx.recyclerview.widget.DividerItemDecoration
import androidx.recyclerview.widget.LinearLayoutManager
import com.mindorks.framework.mvi.R
import com.mindorks.framework.mvi.data.api.ApiHelperImpl
import com.mindorks.framework.mvi.data.api.RetrofitBuilder
import com.mindorks.framework.mvi.data.model.User
import com.mindorks.framework.mvi.util.ViewModelFactory
import com.mindorks.framework.mvi.ui.main.adapter.MainAdapter
import com.mindorks.framework.mvi.ui.main.intent.MainIntent
import com.mindorks.framework.mvi.ui.main.viewmodel.MainViewModel
import com.mindorks.framework.mvi.ui.main.viewstate.MainState
import kotlinx.android.synthetic.main.activity_main.*
import kotlinx.coroutines.ExperimentalCoroutinesApi
import kotlinx.coroutines.flow.collect
import kotlinx.coroutines.launch
 
@ExperimentalCoroutinesApi
class MainActivity : AppCompatActivity() {
 
    private lateinit var mainViewModel: MainViewModel
    private var adapter = MainAdapter(arrayListOf())
 
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        setupUI()
        setupViewModel()
        observeViewModel()
        setupClicks()
    }
 
    private fun setupClicks() {
        buttonFetchUser.setOnClickListener {
            lifecycleScope.launch {
                mainViewModel.userIntent.send(MainIntent.FetchUser)
            }
        }
    }
 
 
    private fun setupUI() {
        recyclerView.layoutManager = LinearLayoutManager(this)
        recyclerView.run {
            addItemDecoration(
                DividerItemDecoration(
                    recyclerView.context,
                    (recyclerView.layoutManager as LinearLayoutManager).orientation
                )
            )
        }
        recyclerView.adapter = adapter
    }
 
 
    private fun setupViewModel() {
        mainViewModel = ViewModelProviders.of(
            this,
            ViewModelFactory(
                ApiHelperImpl(
                    RetrofitBuilder.apiService
                )
            )
        ).get(MainViewModel::class.java)
    }
 
    private fun observeViewModel() {
        lifecycleScope.launch {
            mainViewModel.state.collect {
                when (it) {
                    is MainState.Idle -> {
 
                    }
                    is MainState.Loading -> {
                        buttonFetchUser.visibility = View.GONE
                        progressBar.visibility = View.VISIBLE
                    }
 
                    is MainState.Users -> {
                        progressBar.visibility = View.GONE
                        buttonFetchUser.visibility = View.GONE
                        renderList(it.user)
                    }
                    is MainState.Error -> {
                        progressBar.visibility = View.GONE
                        buttonFetchUser.visibility = View.VISIBLE
                        Toast.makeText(this@MainActivity, it.error, Toast.LENGTH_LONG).show()
                    }
                }
            }
        }
    }
 
    private fun renderList(users: List<User>) {
        recyclerView.visibility = View.VISIBLE
        users.let { listOfUsers -> listOfUsers.let { adapter.addData(it) } }
        adapter.notifyDataSetChanged()
    }
}

	<uses-permission android:name="android.permission.INTERNET"/>