Clear storage on logout

LICENSE

@@ -18,4 +18,4 @@ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
+SOFTWARE.

lib/solid_auth_client.dart

@@ -321,6 +321,14 @@ Future<Map> authenticate(
 }
 
 Future<bool> logout(logoutUrl) async {
+  // Clear platform-specific storage (Web: localStorage, Native: SharedPreferences)
+  try {
+    await authManager.clearLocalStorage();
+  } catch (e) {
+    debugPrint('logout() => Warning: Failed to clear storage: $e');
+    // Continue with logout flow even if storage clearing fails
+  }
+
   Uri url = Uri.parse(logoutUrl);
 
   if (await canLaunchUrl(url)) {

lib/src/auth_manager/auth_manager_abstract.dart

@@ -44,6 +44,7 @@ abstract class AuthManager {
   createAuthenticator(Client client, List<String> scopes, String dPopToken) {}
   getOidcWeb() {}
   userLogout(String logoutUrl) {}
+  Future<void> clearLocalStorage() async {}
 
   // factory constructor to return the correct implementation.
   factory AuthManager() => getAuthManager();

lib/src/auth_manager/auth_manager_stub.dart

@@ -28,7 +28,6 @@
 library;
 
 import 'package:solid_auth/src/auth_manager/auth_manager_abstract.dart';
+import 'package:solid_auth/src/auth_manager/native_auth_manager.dart';
 
-AuthManager getAuthManager() => throw UnsupportedError(
-      'Cannot create a keyfinder without the packages dart:html or package:shared_preferences',
-    );
+AuthManager getAuthManager() => NativeAuthManager();

lib/src/auth_manager/native_auth_manager.dart

@@ -0,0 +1,79 @@
+/// Native Auth Manager for non-web platforms.
+///
+/// Copyright (C) 2025, Software Innovation Institute, ANU.
+///
+/// Licensed under the MIT License (the "License").
+///
+/// License: https://choosealicense.com/licenses/mit/.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+///
+/// Authors: Anushka Vidanage
+library;
+
+import 'package:shared_preferences/shared_preferences.dart';
+import 'package:solid_auth/src/auth_manager/auth_manager_abstract.dart';
+import 'package:solid_auth/src/openid/src/openid.dart';
+
+/// Auth manager implementation for native platforms (Linux, Windows, macOS, iOS, Android).
+///
+/// This provides platform-specific implementations using SharedPreferences
+/// for storage operations on native platforms.
+class NativeAuthManager implements AuthManager {
+  @override
+  String getKeyValue(String key) {
+    // Native platforms don't use localStorage
+    return '';
+  }
+
+  @override
+  getWebUrl() {
+    // Not applicable for native platforms
+    return null;
+  }
+
+  @override
+  createAuthenticator(Client client, List<String> scopes, String dPopToken) {
+    // Not applicable for native platforms
+    return null;
+  }
+
+  @override
+  getOidcWeb() {
+    // Not applicable for native platforms
+    return null;
+  }
+
+  @override
+  userLogout(String logoutUrl) {
+    // Native platforms handle logout through URL launcher, not window.open
+  }
+
+  @override
+  Future<void> clearLocalStorage() async {
+    try {
+      final prefs = await SharedPreferences.getInstance();
+      await prefs.clear();
+    } catch (e) {
+      throw Exception('Failed to clear SharedPreferences: $e');
+    }
+  }
+}
+
+AuthManager getAuthManager() => NativeAuthManager();

lib/src/auth_manager/web_auth_manager.dart

@@ -80,6 +80,15 @@ class WebAuthManager implements AuthManager {
     final child = window.open(logoutUrl, 'user_logout');
     child!.close();
   }
+
+  @override
+  Future<void> clearLocalStorage() async {
+    try {
+      windowLoc.localStorage.clear();
+    } catch (e) {
+      throw Exception('Failed to clear localStorage: $e');
+    }
+  }
 }
 
 AuthManager getAuthManager() => WebAuthManager();

pubspec.yaml

@@ -22,6 +22,7 @@ dependencies:
   url_launcher: ^6.3.1
   uuid: ^4.5.1
   web: ^1.1.1
+  shared_preferences: ^2.2.2
 
 dev_dependencies:
   flutter_lints: ^5.0.0