Updated application preferences logic

lib/helpers/account_credentials_helper.dart

@@ -1,33 +0,0 @@
-import 'dart:convert';
-
-import 'package:comunic/models/login_tokens.dart';
-import 'package:shared_preferences/shared_preferences.dart';
-
-/// Accounts credentials helper
-///
-/// Stores current account tokens
-///
-/// @author Pierre HUBERT
-
-class AccountCredentialsHelper {
-
-  /// Set new login tokens
-  Future<void> set(LoginTokens tokens) async {
-    SharedPreferences prefs = await SharedPreferences.getInstance();
-    await prefs.setString(
-        "login_tokens", tokens == null ? "null" : tokens.toString());
-  }
-
-  /// Get current [LoginTokens]. Returns null if none or in case of failure
-  Future<LoginTokens> get() async {
-    try {
-      SharedPreferences prefs = await SharedPreferences.getInstance();
-      final string = prefs.getString("login_tokens");
-      if (string == null || string == "null") return null;
-      return LoginTokens.fromJSON(jsonDecode(string));
-    } on Exception catch (e) {
-      print(e.toString());
-      return null;
-    }
-  }
-}

lib/helpers/account_helper.dart

@@ -1,5 +1,5 @@
-import 'package:comunic/helpers/account_credentials_helper.dart';
 import 'package:comunic/helpers/api_helper.dart';
+import 'package:comunic/helpers/preferences_helper.dart';
 import 'package:comunic/models/api_request.dart';
 import 'package:comunic/models/authentication_details.dart';
 import 'package:comunic/models/login_tokens.dart';
@@ -26,7 +26,8 @@ class AccountHelper {
   ///
   /// Warning : This method MUST BE CALLED AT LEAST ONCE AFTER APP START !!!
   Future<bool> signedIn() async {
-    bool signedIn = await AccountCredentialsHelper().get() != null;
+    bool signedIn =
+        (await PreferencesHelper.getInstance()).getLoginTokens() != null;
 
     // Load current user ID for later use
     if (signedIn && _currentUserID == -1) await _loadCurrentUserID();
@@ -51,8 +52,8 @@ class AccountHelper {
 
     // Save login tokens
     final tokensObj = response.getObject()["tokens"];
-    await AccountCredentialsHelper()
+    await (await PreferencesHelper.getInstance())
-        .set(LoginTokens(tokensObj["token1"], tokensObj["token2"]));
+        .setLoginTokens(LoginTokens(tokensObj["token1"], tokensObj["token2"]));
 
     // Get current user ID
     final userID = await _downloadCurrentUserID();
@@ -71,7 +72,7 @@ class AccountHelper {
 
   /// Sign out user
   Future<void> signOut() async {
-    await AccountCredentialsHelper().set(null);
+    await (await PreferencesHelper.getInstance()).setLoginTokens(null);
     _currentUserID = 0;
   }
 

lib/helpers/api_helper.dart

@@ -1,6 +1,6 @@
 import 'dart:io';
 
-import 'package:comunic/helpers/account_credentials_helper.dart';
+import 'package:comunic/helpers/preferences_helper.dart';
 import 'package:comunic/models/api_request.dart';
 import 'package:comunic/models/api_response.dart';
 import 'package:comunic/models/config.dart';
@@ -23,7 +23,7 @@ class APIHelper {
 
       //Add user tokens (if required)
       if (request.needLogin) {
-        final tokens = await AccountCredentialsHelper().get();
+        final tokens = (await PreferencesHelper.getInstance()).getLoginTokens();
         assert(tokens != null);
         request.addString("userToken1", tokens.tokenOne);
         request.addString("userToken2", tokens.tokenTwo);

lib/helpers/preferences_helper.dart

@@ -0,0 +1,49 @@
+import 'dart:convert';
+
+import 'package:comunic/models/login_tokens.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+/// Preferences helper
+///
+/// Stores current account tokens
+///
+/// @author Pierre HUBERT
+
+class PreferencesHelper {
+  static PreferencesHelper _instance;
+
+  static Future<PreferencesHelper> getInstance() async {
+    if (_instance == null) {
+      _instance = PreferencesHelper._();
+      await _init();
+    }
+
+    return _instance;
+  }
+
+  static SharedPreferences _sharedPreferences;
+
+  PreferencesHelper._();
+
+  static Future<void> _init() async {
+    _sharedPreferences = await SharedPreferences.getInstance();
+  }
+
+  /// Set new login tokens
+  Future<void> setLoginTokens(LoginTokens tokens) async {
+    await _sharedPreferences.setString(
+        "login_tokens", tokens == null ? "null" : tokens.toString());
+  }
+
+  /// Get current [LoginTokens]. Returns null if none or in case of failure
+  LoginTokens getLoginTokens() {
+    try {
+      final string = _sharedPreferences.getString("login_tokens");
+      if (string == null || string == "null") return null;
+      return LoginTokens.fromJSON(jsonDecode(string));
+    } on Exception catch (e) {
+      print(e.toString());
+      return null;
+    }
+  }
+}