Flutter Next Auth

A Flutter package for NextERP (Frappe/ERPNext) authentication with secure session management.

Features

✅ Login with username and password
✅ Logout functionality
✅ Password reset request
✅ Password change/update
✅ Session management with secure storage (SID)
✅ Automatic re-authentication using stored session
✅ Get logged user profile
✅ Simple, intuitive API

Installation

Add this to your package's pubspec.yaml file:

dependencies:
  flutter_next_auth: ^1.0.0

Then run:

flutter pub get

Platform-Specific Setup

Android

Add the following to your android/app/src/main/AndroidManifest.xml inside the <application> tag:

<application>
    <!-- Other configurations -->
    <activity
        android:name=".MainActivity"
        android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
        android:hardwareAccelerated="true"
        android:windowSoftInputMode="adjustResize">
    </activity>
</application>

iOS

No additional setup required.

Linux

sudo apt-get install libsecret-1-dev

Usage

1. Initialize

Initialize the package with your NextERP server URL before using any authentication methods:

import 'package:flutter_next_auth/flutter_next_auth.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  
  // Initialize FlutterNext with your server URL
  await flutternext.initialize(
    baseUrl: 'https://your-erp-server.com',
  );
  
  runApp(MyApp());
}

2. Login

final result = await flutternext.login(
  usr: 'username@example.com',
  pwd: 'password123',
);

if (result.success) {
  print('Logged in as ${result.username}');
  print('Full name: ${result.fullName}');
  print('Session ID: ${result.sid}');
  // Navigate to home screen
} else {
  print('Login failed: ${result.message}');
  // Show error message
}

3. Relogin (Auto-Login)

Use this to restore a user's session when the app starts:

final result = await flutternext.relogin();

if (result.success) {
  print('Session restored for ${result.user?.username}');
  // Navigate to home screen
} else {
  print('No valid session: ${result.message}');
  // Navigate to login screen
}

4. Logout

final result = await flutternext.logout();

if (result.success) {
  print('Logged out successfully');
  // Navigate to login screen
} else {
  print('Logout error: ${result.message}');
}

5. Reset Password

final result = await flutternext.resetPassword(
  user: 'username@example.com',
);

if (result.success) {
  print(result.message);
  // Show success message
} else {
  print('Reset failed: ${result.message}');
}

6. Change Password

final result = await flutternext.changePassword(
  oldPassword: 'currentpass123',
  newPassword: 'newpass456',
);

if (result.success) {
  print('Password changed successfully');
} else {
  print('Change failed: ${result.message}');
}

7. Get User Profile

final user = await flutternext.getUserProfile();

if (user != null) {
  print('Username: ${user.username}');
  print('Full name: ${user.fullName}');
  print('Email: ${user.email}');
}

8. Check Active Session

bool hasSession = await flutternext.hasActiveSession();

if (hasSession) {
  print('User has an active session');
}

9. Get Stored Data

// Get stored session ID
String? sid = await flutternext.getStoredSid();

// Get stored username
String? username = await flutternext.getStoredUsername();

// Get stored full name
String? fullName = await flutternext.getStoredFullName();

Complete Example

import 'package:flutter/material.dart';
import 'package:flutter_next_auth/flutter_next_auth.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  
  await flutternext.initialize(
    baseUrl: 'https://demo.erpnext.com',
  );
  
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Next Auth Demo',
      home: LoginScreen(),
    );
  }
}

class LoginScreen extends StatefulWidget {
  @override
  _LoginScreenState createState() => _LoginScreenState();
}

class _LoginScreenState extends State<LoginScreen> {
  final _usernameController = TextEditingController();
  final _passwordController = TextEditingController();
  bool _isLoading = false;

  @override
  void initState() {
    super.initState();
    _checkExistingSession();
  }

  Future<void> _checkExistingSession() async {
    final result = await flutternext.relogin();
    if (result.success) {
      _navigateToHome();
    }
  }

  Future<void> _handleLogin() async {
    setState(() => _isLoading = true);

    final result = await flutternext.login(
      usr: _usernameController.text,
      pwd: _passwordController.text,
    );

    setState(() => _isLoading = false);

    if (result.success) {
      _navigateToHome();
    } else {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text(result.message ?? 'Login failed')),
      );
    }
  }

  void _navigateToHome() {
    Navigator.of(context).pushReplacement(
      MaterialPageRoute(builder: (_) => HomeScreen()),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('Login')),
      body: Padding(
        padding: EdgeInsets.all(16),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            TextField(
              controller: _usernameController,
              decoration: InputDecoration(labelText: 'Username'),
            ),
            SizedBox(height: 16),
            TextField(
              controller: _passwordController,
              decoration: InputDecoration(labelText: 'Password'),
              obscureText: true,
            ),
            SizedBox(height: 24),
            ElevatedButton(
              onPressed: _isLoading ? null : _handleLogin,
              child: _isLoading
                  ? CircularProgressIndicator()
                  : Text('Login'),
            ),
          ],
        ),
      ),
    );
  }
}

class HomeScreen extends StatelessWidget {
  Future<void> _handleLogout(BuildContext context) async {
    await flutternext.logout();
    Navigator.of(context).pushReplacement(
      MaterialPageRoute(builder: (_) => LoginScreen()),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Home'),
        actions: [
          IconButton(
            icon: Icon(Icons.logout),
            onPressed: () => _handleLogout(context),
          ),
        ],
      ),
      body: Center(
        child: FutureBuilder<UserProfile?>(
          future: flutternext.getUserProfile(),
          builder: (context, snapshot) {
            if (snapshot.hasData) {
              final user = snapshot.data!;
              return Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Text('Welcome, ${user.fullName ?? user.username}!'),
                  SizedBox(height: 16),
                  Text('Email: ${user.email ?? "N/A"}'),
                ],
              );
            }
            return CircularProgressIndicator();
          },
        ),
      ),
    );
  }
}

How It Works

Session Management

1. Login: When you call flutternext.login(), the package:

   • Sends credentials to NextERP server
   • Receives a session ID (SID) in response cookies
   • Stores the SID securely using flutter_secure_storage
   • Returns user information

2. Relogin: When you call flutternext.relogin(), the package:

   • Retrieves the stored SID from secure storage
   • Makes a request to get the logged-in user profile
   • If successful, the session is still valid
   • If failed, clears the stored session

3. Authenticated Requests: All subsequent API calls automatically include the stored SID in the cookie header

4. Logout: Clears both server-side session and local storage

Secure Storage

The package uses flutter_secure_storage to securely store:

• Session ID (SID)
• Username
• Full name

This data persists across app restarts and is encrypted on the device.

API Reference

Methods

Method	Parameters	Returns	Description
initialize()	baseUrl, timeout?	Future<void>	Initialize with server URL
login()	usr, pwd	Future<LoginResult>	Login with credentials
logout()	-	Future<LogoutResult>	Logout and clear session
relogin()	-	Future<ReloginResult>	Restore session from storage
resetPassword()	user	Future<PasswordResetResult>	Request password reset
changePassword()	oldPassword, newPassword	Future<PasswordChangeResult>	Change password
getUserProfile()	-	Future<UserProfile?>	Get current user info
hasActiveSession()	-	Future<bool>	Check if session exists
getStoredSid()	-	Future<String?>	Get stored session ID
getStoredUsername()	-	Future<String?>	Get stored username
getStoredFullName()	-	Future<String?>	Get stored full name
clearStoredSession()	-	Future<void>	Clear local session data

Models

• LoginResult: Contains success status, username, full name, and SID
• LogoutResult: Contains success status and message
• ReloginResult: Contains success status, message, and user profile
• PasswordResetResult: Contains success status and message
• PasswordChangeResult: Contains success status and message
• UserProfile: Contains username, full name, and email

Error Handling

All methods return result objects with a success boolean and optional message string:

final result = await flutternext.login(usr: username, pwd: password);

if (!result.success) {
  // Handle error
  print('Error: ${result.message}');
}

License

MIT License - see LICENSE file for details

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Support

For issues, questions, or contributions, please visit the GitHub repository.