Modify the DataStore sample app to work with the new Preferences API.

Author: rohitsat13

app/src/main/java/com/codelab/android/datastore/data/UserPreferencesRepository.kt

@@ -19,19 +19,13 @@ package com.codelab.android.datastore.data
 import android.content.Context
 import android.util.Log
 import androidx.datastore.DataStore
-import androidx.datastore.preferences.PreferenceDataStoreFactory
-import androidx.datastore.preferences.Preferences
-import androidx.datastore.preferences.SharedPreferencesMigration
+import androidx.datastore.preferences.*
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.catch
 import kotlinx.coroutines.flow.map
-import java.io.File
 import java.io.IOException
 
 private const val USER_PREFERENCES_NAME = "user_preferences"
-private const val USER_PREFERENCES_STORE_FILE_NAME = "user.preferences_pb"
-private const val SORT_ORDER_KEY = "sort_order"
-private const val SHOW_COMPLETED_KEY = "show_completed"
 
 enum class SortOrder {
     NONE,
@@ -41,24 +35,10 @@ enum class SortOrder {
 }
 
 data class UserPreferences(
-    val showCompleted: Boolean,
+    val showCompleted: Boolean = false,
     val sortOrder: SortOrder
 )
 
-/**
- * Extension function on Preferences to easily get the sort order
- */
-private fun Preferences.getSortOrder(): SortOrder {
-    val order = getString(SORT_ORDER_KEY, SortOrder.NONE.name)
-    return SortOrder.valueOf(order)
-}
-
-/**
- * Extension function on Preferences to easily set the sort order
- */
-private fun Preferences.withSortOrder(newSortOrder: SortOrder) =
-    this.toBuilder().setString(SORT_ORDER_KEY, newSortOrder.name).build()
-
 /**
  * Class that handles saving and retrieving user preferences
  */
@@ -67,19 +47,17 @@ class UserPreferencesRepository private constructor(context: Context) {
     private val TAG: String = "UserPreferencesRepo"
 
     private val dataStore: DataStore<Preferences> by lazy {
-        PreferenceDataStoreFactory().create(
-            produceFile = {
-                File(
-                    context.applicationContext.filesDir,
-                    USER_PREFERENCES_STORE_FILE_NAME
-                )
-            },
-            // Since we're migrating from SharedPreferences, add a migration based on the
-            // SharedPreferences name
-            migrationProducers = listOf(SharedPreferencesMigration(context, USER_PREFERENCES_NAME))
+        context.createDataStore(
+            name = USER_PREFERENCES_NAME,
+            migrations = listOf(SharedPreferencesMigration(context, USER_PREFERENCES_NAME))
         )
     }
 
+    private object Keys {
+        internal val SORT_ORDER_KEY = preferencesKey<String>("sort_order")
+        internal val SHOW_COMPLETED_KEY = preferencesKey<Boolean>("show_completed")
+    }
+
     /**
      * Get the user preferences flow.
      */
@@ -88,14 +66,17 @@ class UserPreferencesRepository private constructor(context: Context) {
             // dataStore.data throws an IOException when an error is encountered when reading data
             if (exception is IOException) {
                 Log.e(TAG, "Error reading preferences.", exception)
-                emit(Preferences.empty())
+                emit(emptyPreferences())
             } else {
                 throw exception
             }
         }.map { preferences ->
             // Get the sort order from preferences and convert it to a [SortOrder] object
-            val sortOrder = preferences.getSortOrder()
-            val showCompleted = preferences.getBoolean(SHOW_COMPLETED_KEY, false)
+            val sortOrder =
+                SortOrder.valueOf(
+                    preferences[Keys.SORT_ORDER_KEY] ?: SortOrder.NONE.name
+                )
+            val showCompleted = preferences[Keys.SHOW_COMPLETED_KEY] ?: false
             UserPreferences(showCompleted, sortOrder)
         }
 
@@ -105,9 +86,10 @@ class UserPreferencesRepository private constructor(context: Context) {
     suspend fun enableSortByDeadline(enable: Boolean) {
         // updateData handles data transactionally, ensuring that if the sort is updated at the same
         // time from another thread, we won't have conflicts
-        dataStore.updateData { currentPreferences ->
-            val currentOrder = currentPreferences.getSortOrder()
-            val newSortOrder =
+        dataStore.edit { prefs ->
+            val currentOrder = prefs[Keys.SORT_ORDER_KEY]?.let { SortOrder.valueOf(it) }
+
+            val newSortOrder  =
                 if (enable) {
                     if (currentOrder == SortOrder.BY_PRIORITY) {
                         SortOrder.BY_DEADLINE_AND_PRIORITY
@@ -121,7 +103,8 @@ class UserPreferencesRepository private constructor(context: Context) {
                         SortOrder.NONE
                     }
                 }
-            currentPreferences.withSortOrder(newSortOrder)
+
+            prefs[Keys.SORT_ORDER_KEY] = newSortOrder.name
         }
     }
 
@@ -131,8 +114,9 @@ class UserPreferencesRepository private constructor(context: Context) {
     suspend fun enableSortByPriority(enable: Boolean) {
         // updateData handles data transactionally, ensuring that if the sort is updated at the same
         // time from another thread, we won't have conflicts
-        dataStore.updateData { currentPreferences ->
-            val currentOrder = currentPreferences.getSortOrder()
+        dataStore.edit { prefs ->
+            val currentOrder = prefs[Keys.SORT_ORDER_KEY]?.let { SortOrder.valueOf(it) }
+
             val newSortOrder =
                 if (enable) {
                     if (currentOrder == SortOrder.BY_DEADLINE) {
@@ -147,13 +131,14 @@ class UserPreferencesRepository private constructor(context: Context) {
                         SortOrder.NONE
                     }
                 }
-            currentPreferences.withSortOrder(newSortOrder)
+
+            prefs[Keys.SORT_ORDER_KEY] = newSortOrder.name
         }
     }
 
     suspend fun updateShowCompleted(showCompleted: Boolean) {
-        dataStore.updateData { currentPreferences ->
-            currentPreferences.toBuilder().setBoolean(SHOW_COMPLETED_KEY, showCompleted).build()
+        dataStore.edit { prefs ->
+            prefs[Keys.SHOW_COMPLETED_KEY] = showCompleted
         }
     }