Kotlin-Mvvm-DaggerHilt-Preferences Data Store-Example

Kotlin-Mvvm-DaggerHilt-Preferences Data Store-Example

Step 1:

Open build.gradle(:Project) and add following dependency and rebuild the project.

// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
    repositories {
        google()
        mavenCentral()
    }
    dependencies {
        classpath "com.android.tools.build:gradle:7.0.4"
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.5.20"
        classpath 'com.google.dagger:hilt-android-gradle-plugin:2.40.5'
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

Step 2:

Open build.gradle(:app) and add following dependency and rebuild the project.

plugins {
    id 'com.android.application'
    id 'kotlin-android'
    id 'kotlin-kapt'
    id 'dagger.hilt.android.plugin'
}
android {
    compileSdk 31
    defaultConfig {
        applicationId "in.kotlinkatta.kotlinkattademo"
        minSdk 21
        targetSdk 31
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
    kotlinOptions {
        jvmTarget = '1.8'
    }

    buildFeatures{
        dataBinding true;
        viewBinding true
    }
}

dependencies {
    implementation 'androidx.core:core-ktx:1.7.0'
    implementation 'androidx.appcompat:appcompat:1.4.1'
    implementation 'com.google.android.material:material:1.5.0'
    implementation 'androidx.constraintlayout:constraintlayout:2.1.3'
    testImplementation 'junit:junit:4.+'
    androidTestImplementation 'androidx.test.ext:junit:1.1.3'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
    //kotlin Coroutines
    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.5.2'
    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.5.2'
    //room
    implementation "androidx.room:room-ktx:2.4.1"
    implementation "androidx.room:room-runtime:2.4.1"
    kapt "androidx.room:room-compiler:2.4.1"
    //multidex
    implementation 'androidx.multidex:multidex:2.0.1'
    // ViewModel
    implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:2.4.0"
    // LiveData
    implementation "androidx.lifecycle:lifecycle-livedata-ktx:2.4.0"
    // view model ktx
    implementation 'androidx.activity:activity-ktx:1.4.0'
    //hilt viewmodel
    implementation 'androidx.hilt:hilt-lifecycle-viewmodel:1.0.0-alpha03'
    kapt("org.jetbrains.kotlinx:kotlinx-metadata-jvm:0.3.0")
    //retrofit
    implementation 'com.squareup.retrofit2:retrofit:2.9.0'
    //moshi
    implementation("com.squareup.moshi:moshi-kotlin:1.12.0")
    implementation 'com.squareup.retrofit2:converter-moshi:2.9.0'
    //SharedPreferences
    implementation("androidx.datastore:datastore:1.0.0")
    implementation("androidx.datastore:datastore-preferences:1.0.0")
    //DaggerHilt
    implementation 'com.google.dagger:hilt-android:2.40.5'
    kapt 'com.google.dagger:hilt-compiler:2.40.5'
}
// Allow references to generated code
kapt {
    correctErrorTypes = true
}

Step 3:

Open gradle.properties and add following code and rebuild the project.

kapt.use.worker.api=false

Step 4:

Open AndroidManifest.xml and add following dependency and rebuild the project.

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="in.kotlinkatta.kotlinkattademo">
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.INTERNET"/>
    <application
        android:name=".container.BaseApp"
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.KotlinKattaDemo">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>

App Flow Image:

Step 5:

Create new class BaseApp.kt and add following code.

package `in`.kotlinkatta.kotlinkattademo.container

import android.app.Application
import dagger.hilt.android.HiltAndroidApp

@HiltAndroidApp
class BaseApp : Application() {}

Step 6:

Create new class AppDataStore.kt and add following code.

package `in`.kotlinkatta.kotlinkattademo.datastore

import android.content.Context
import androidx.datastore.preferences.core.edit
import androidx.datastore.preferences.core.emptyPreferences
import androidx.datastore.preferences.core.stringPreferencesKey
import androidx.datastore.preferences.preferencesDataStore
import dagger.hilt.android.qualifiers.ApplicationContext
import kotlinx.coroutines.flow.Flow
import kotlinx.coroutines.flow.catch
import kotlinx.coroutines.flow.map
import java.io.IOException
import javax.inject.Inject

class AppDataStore @Inject constructor(@ApplicationContext val context: Context) {

    companion object {
        private val Context.dataStore by preferencesDataStore(name = "kotlinkatta")
    }

    object PreferencesKey {
        val user_id = stringPreferencesKey("user_id")
        val user_name = stringPreferencesKey("user_name")
        val user_email = stringPreferencesKey("user_email")
    }

    suspend fun saveToLocal_AllData(
        user_id: String,
        user_name: String,
        user_email: String
    ) {
        context.dataStore.edit { preference ->
            preference[PreferencesKey.user_id] = user_id
            preference[PreferencesKey.user_name] = user_name
            preference[PreferencesKey.user_email] = user_email
        }
    }

    suspend fun saveToLocal_user_id(user_id: String) {
        context.dataStore.edit { preference ->
            preference[PreferencesKey.user_id] = user_id
        }
    }

    suspend fun saveToLocal_user_name(user_name: String) {
        context.dataStore.edit { preference ->
            preference[PreferencesKey.user_name] = user_name
        }
    }

    suspend fun saveToLocal_user_email(user_email: String) {
        context.dataStore.edit { preference ->
            preference[PreferencesKey.user_email] = user_email
        }
    }

    val readFromLocal_user_id: Flow<String> = context.dataStore.data
        .catch { it ->
            if (this is Exception) {
                emit(emptyPreferences())
            }
        }.map { preference ->
            val user_id = preference[PreferencesKey.user_id] ?: ""
            user_id
        }

    val readFromLocal_user_name: Flow<String> = context.dataStore.data
        .catch { exception ->
            if (exception is IOException) {
                emit(emptyPreferences())
            } else {
                throw exception
            }
        }.map { preference ->
            val user_name = preference[PreferencesKey.user_name] ?: ""
            user_name
        }

    val readFromLocal_user_email: Flow<String> = context.dataStore.data
        .catch { it ->
            if (this is Exception) {
                emit(emptyPreferences())
            }
        }.map { preference ->
            val user_email = preference[PreferencesKey.user_email] ?: ""
            user_email
        }

    suspend fun deleteAllDataStoreData() {
        context.dataStore.edit { preference ->
            preference.clear()
        }
    }
}

Step 7:

Create new class AppDataStoreViewModel.kt and add following code.

package `in`.kotlinkatta.kotlinkattademo.uiviewmodel

import `in`.kotlinkatta.kotlinkattademo.datastore.AppDataStore
import androidx.lifecycle.ViewModel
import androidx.lifecycle.viewModelScope
import dagger.hilt.android.lifecycle.HiltViewModel
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.launch
import javax.inject.Inject

@HiltViewModel
class AppDataStoreViewModel
@Inject
constructor(private val appDataStore: AppDataStore) : ViewModel() {

    fun saveToLocal_AllData(user_id: String, user_name: String, user_email: String) =
        viewModelScope.launch(Dispatchers.IO) {
            appDataStore.saveToLocal_AllData(user_id, user_name, user_email)
        }

    fun saveToLocal_user_id(user_id: String) =
        viewModelScope.launch(Dispatchers.IO) {
            appDataStore.saveToLocal_user_id(user_id)
        }

    fun saveToLocal_user_name(user_name: String) =
        viewModelScope.launch(Dispatchers.IO) {
            appDataStore.saveToLocal_user_name(user_name)
        }

    fun saveToLocal_user_email(user_email: String) =
        viewModelScope.launch(Dispatchers.IO) {
            appDataStore.saveToLocal_user_email(user_email)
        }

    val readFromLocal_user_id = appDataStore.readFromLocal_user_id
    val readFromLocal_user_name = appDataStore.readFromLocal_user_name
    val readFromLocal_user_email = appDataStore.readFromLocal_user_email

    fun deleteAllDataStoreData() =
        viewModelScope.launch(Dispatchers.IO) {
            appDataStore.deleteAllDataStoreData()
        }
}

Step 8:

Open layout xml file activity_main.xml and add following code.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical"
    android:layout_margin="15dp"
    tools:context=".MainActivity">
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Preference Data Stored"
        android:textSize="30dp"
        android:gravity="center"
        android:layout_marginTop="10dp"
        android:layout_marginBottom="30dp"/>
    <EditText
        android:id="@+id/edtuserid"
        android:hint="Enter User Id"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="5dp"
        android:layout_margin="5dp"
        android:inputType="number"
        android:background="#E7E7E7"/>
    <EditText
        android:id="@+id/edtusername"
        android:hint="Enter User Name"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="5dp"
        android:layout_margin="5dp"
        android:background="#E7E7E7"/>
    <EditText
        android:id="@+id/edtuseremail"
        android:hint="Enter User Email"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="5dp"
        android:layout_margin="5dp"
        android:background="#E7E7E7"/>

    <LinearLayout
        android:layout_marginTop="30dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:gravity="center">

        <Button
            android:id="@+id/btnsave"
            android:layout_margin="5dp"
            android:layout_weight="1"
            android:text="Save"
            android:textAllCaps="false"
            android:background="#FF03DAC5"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />
        <Button
            android:id="@+id/btnview"
            android:layout_margin="5dp"
            android:layout_weight="1"
            android:textAllCaps="false"
            android:text="View"
            android:background="#FF03DAC5"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />
        <Button
            android:id="@+id/btnclear"
            android:layout_margin="5dp"
            android:layout_weight="1"
            android:textAllCaps="false"
            android:text="Clear"
            android:background="#FF03DAC5"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />
    </LinearLayout>

    <TextView
        android:id="@+id/txtUserId"
        android:layout_marginTop="10dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="18dp"/>
    <TextView
        android:id="@+id/txtUserName"
        android:layout_marginTop="10dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="18dp"/>
    <TextView
        android:id="@+id/txtUserEmail"
        android:layout_marginTop="10dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="18dp"/>
</LinearLayout>

Step 9:

Open Activity class file MainActivity.kt and add following code.

package `in`.kotlinkatta.kotlinkattademo

import `in`.kotlinkatta.kotlinkattademo.databinding.ActivityMainBinding
import `in`.kotlinkatta.kotlinkattademo.uiviewmodel.AppDataStoreViewModel
import android.os.Bundle
import android.widget.Toast
import androidx.activity.viewModels
import androidx.appcompat.app.AppCompatActivity
import androidx.lifecycle.lifecycleScope
import dagger.hilt.android.AndroidEntryPoint
import kotlinx.coroutines.flow.collect

@AndroidEntryPoint
public class MainActivity : AppCompatActivity() {

    private lateinit var binding: ActivityMainBinding
    private val appDataStoreViewModel: AppDataStoreViewModel by viewModels()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityMainBinding.inflate(layoutInflater)
        val view = binding.root
        setContentView(view)
        funAllBtnClick()
        funDisplayData()
    }

    private fun funAllBtnClick() {
        binding.btnsave.setOnClickListener {
            val str_user_id = binding.edtuserid.text.toString()
            val str_name = binding.edtusername.text.toString()
            val str_email = binding.edtuseremail.text.toString()

            if (str_user_id.equals("") || str_name.equals("") || str_email.equals("")) {
                Toast.makeText(this, "Please Enter Details.", Toast.LENGTH_SHORT).show()
            } else {
                appDataStoreViewModel.saveToLocal_AllData(str_user_id, str_name, str_email)
                Toast.makeText(this, "Data Saved Successfully.", Toast.LENGTH_SHORT).show()
            }
            binding.edtuserid.text.clear()
            binding.edtusername.text.clear()
            binding.edtuseremail.text.clear()
        }

        binding.btnview.setOnClickListener {
            funDisplayData()
        }

        binding.btnclear.setOnClickListener {
            appDataStoreViewModel.deleteAllDataStoreData()
        }
    }

    private fun funDisplayData() {
        lifecycleScope.launchWhenStarted {
            appDataStoreViewModel.readFromLocal_user_id.collect { strUserId ->
                binding.txtUserId.text = "UserId : " + strUserId
            }
        }

        lifecycleScope.launchWhenStarted {
            appDataStoreViewModel.readFromLocal_user_name.collect { strUserName ->
                binding.txtUserName.text = "UserName : " + strUserName
            }
        }

        lifecycleScope.launchWhenStarted {
            appDataStoreViewModel.readFromLocal_user_email.collect { strUserEmail ->
                binding.txtUserEmail.text = "UserEmail : " + strUserEmail
            }
        }
    }
}

Output :