Implementation of Functions.

PreferenceDataStoreHelper.kt

package com.example.datastoretest.data.local

import android.content.Context
import androidx.datastore.preferences.core.Preferences
import androidx.datastore.preferences.core.edit
import androidx.datastore.preferences.core.emptyPreferences
import androidx.datastore.preferences.preferencesDataStore
import kotlinx.coroutines.flow.Flow
import kotlinx.coroutines.flow.catch
import kotlinx.coroutines.flow.first
import kotlinx.coroutines.flow.map
import java.io.IOException

// Declaring/Creating the DataStore File for Application
private val Context.dataStore by preferencesDataStore(
    name = "PreferenceDataStore"
)
class PreferenceDataStoreHelper(context: Context):IPreferenceDataStoreAPI {

    // dataSource access the DataStore file and does the manipulation based on our requirements.
    private val dataSource = context.dataStore

  /* This returns us a flow of data from DataStore. 
  Basically as soon we update the value in Datastore, 
  the values returned by it also changes. */
    override suspend fun <T> getPreference(key: Preferences.Key<T>, defaultValue: T):
            Flow<T> = dataSource.data.catch { exception ->
        if (exception is IOException){
            emit(emptyPreferences())
        }else{
            throw exception
        }
    }.map { preferences->
        val result = preferences[key]?: defaultValue
        result
    }

    /* This returns the last saved value of the key. If we change the value, 
        it wont effect the values produced by this function */
    override suspend fun <T> getFirstPreference(key: Preferences.Key<T>, defaultValue: T) :
            T = dataSource.data.first()[key] ?: defaultValue

  // This Sets the value based on the value passed in value parameter.
    override suspend fun <T> putPreference(key: Preferences.Key<T>, value: T) {
        dataSource.edit {   preferences ->
            preferences[key] = value
        }
    }

    // This Function removes the Key Value pair from the datastore, hereby removing it completely.
    override suspend fun <T> removePreference(key: Preferences.Key<T>) {
        dataSource.edit { preferences ->
            preferences.remove(key)
        }
    }

    // This function clears the entire Preference Datastore.
    override suspend fun <T> clearAllPreference() {
        dataSource.edit { preferences ->
            preferences.clear()
        }
    }
}