Update the protodatastore code: (#7)

* Update the protodatastore code:
1) Use the new factory: context.createDataStore
2) handle unspecified values of SortOrder

Author: rohitsat13

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

@@ -19,66 +19,58 @@ package com.codelab.android.datastore.data
 import android.content.Context
 import android.util.Log
 import androidx.datastore.DataStore
-import androidx.datastore.DataStoreFactory
-import androidx.datastore.migrations.MigrationFromSharedPreferences
+import androidx.datastore.createDataStore
 import androidx.datastore.migrations.SharedPreferencesMigration
 import androidx.datastore.migrations.SharedPreferencesView
 import com.codelab.android.datastore.UserPreferences
 import com.codelab.android.datastore.UserPreferences.SortOrder
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.catch
-import java.io.File
 import java.io.IOException
 
 private const val USER_PREFERENCES_NAME = "user_preferences"
 private const val DATA_STORE_FILE_NAME = "user_prefs.pb"
 private const val SORT_ORDER_KEY = "sort_order"
 
-// Define the mapping from SharedPreferences to UserPreferences
-private class UserPreferencesMigration : MigrationFromSharedPreferences<UserPreferences> {
-    override suspend fun migrate(
-        prefs: SharedPreferencesView,
-        currentData: UserPreferences
-    ): UserPreferences {
-        return if (currentData.sortOrder == SortOrder.UNSPECIFIED) {
-            currentData.toBuilder()
-                .setSortOrder(
-                    SortOrder.valueOf(
-                        prefs.getString(SORT_ORDER_KEY, SortOrder.NONE.name) ?: SortOrder.NONE.name
-                    )
-                )
-                .build()
-        } else {
-            currentData
-        }
-    }
-}
-
 /**
  * Class that handles saving and retrieving user preferences
  */
 class UserPreferencesRepository private constructor(context: Context) {
 
     private val TAG: String = "UserPreferencesRepo"
 
+    private val sharedPrefsMigration = SharedPreferencesMigration(
+        context,
+        USER_PREFERENCES_NAME
+    ) { sharedPrefs: SharedPreferencesView, currentData: UserPreferences ->
+        // Define the mapping from SharedPreferences to UserPreferences
+        if (currentData.sortOrder == SortOrder.UNSPECIFIED) {
+            currentData.toBuilder().setSortOrder(
+                SortOrder.valueOf(
+                    sharedPrefs.getString(
+                        SORT_ORDER_KEY, SortOrder.NONE.name
+                    )!!
+                )
+            ).build()
+        } else {
+            currentData
+        }
+    }
+
+
     // Build the DataStore
-    private val userPreferencesStore: DataStore<UserPreferences> = DataStoreFactory().create(
-        produceFile = { File(context.filesDir, DATA_STORE_FILE_NAME) },
+    private val userPreferencesStore: DataStore<UserPreferences> = context.createDataStore(
+        fileName = DATA_STORE_FILE_NAME,
         serializer = UserPreferencesSerializer,
-        migrationProducers = listOf(
-            SharedPreferencesMigration(
-                context,
-                USER_PREFERENCES_NAME,
-                UserPreferencesMigration()
-            )
-        )
+        migrations = listOf(sharedPrefsMigration)
     )
 
     val userPreferencesFlow: Flow<UserPreferences> = userPreferencesStore.data
         .catch { exception ->
             // dataStore.data throws an IOException when an error is encountered when reading data
             if (exception is IOException) {
                 Log.e(TAG, "Error reading sort order preferences.", exception)
+                emit(UserPreferences.getDefaultInstance())
             } else {
                 throw exception
             }

app/src/main/java/com/codelab/android/datastore/ui/TasksViewModel.kt

@@ -72,6 +72,7 @@ class TasksViewModel(
         }
         // sort the tasks
         return when (sortOrder) {
+            SortOrder.UNSPECIFIED -> filteredTasks
             SortOrder.NONE -> filteredTasks
             SortOrder.BY_DEADLINE -> filteredTasks.sortedByDescending { it.deadline }
             SortOrder.BY_PRIORITY -> filteredTasks.sortedBy { it.priority }