Build a User Management App with Flutter

This tutorial demonstrates how to build a basic user management app. The app authenticates and identifies the user, stores their profile information in the database, and allows the user to log in, update their profile details, and upload a profile photo. The app uses:

Supabase Database - a Postgres database for storing your user data and Row Level Security so data is protected and users can only access their own information.
Supabase Auth - users log in through magic links sent to their email (without having to set up passwords).
Supabase Storage - users can upload a profile photo.

Supabase User Management example

If you get stuck while working through this guide, refer to the full example on GitHub.

Project setup

Before we start building we're going to set up our Database and API. This is as simple as starting a new Project in Supabase and then creating a "schema" inside the database.

Create a project

Create a new project in the Supabase Dashboard.
Enter your project details.
Wait for the new database to launch.

Set up the database schema

Now we are going to set up the database schema. We can use the "User Management Starter" quickstart in the SQL Editor, or you can just copy/paste the SQL from below and run it yourself.

Go to the SQL Editor page in the Dashboard.
Click User Management Starter.
Click Run.

You can easily pull the database schema down to your local project by running the db pull command. Read the local development docs for detailed instructions.


_10supabase link --project-ref <project-id>
_10# You can get <project-id> from your project's dashboard URL: https://supabase.com/dashboard/project/<project-id>
_10supabase db pull

Get the API Keys

Now that you've created some database tables, you are ready to insert data using the auto-generated API. We just need to get the Project URL and anon key from the API settings.

Go to the API Settings page in the Dashboard.
Find your Project URL, anon, and service_role keys on this page.

Building the app

Let's start building the Flutter app from scratch.

Initialize a Flutter app

We can use flutter create to initialize an app called supabase_quickstart:


_10flutter create supabase_quickstart

Then let's install the only additional dependency: supabase_flutter

Copy and paste the following line in your pubspec.yaml to install the package:


_10supabase_flutter: ^2.0.0

Run flutter pub get to install the dependencies.

Setup deep links

Now that we have the dependencies installed let's setup deep links. Setting up deep links is required to bring back the user to the app when they click on the magic link to sign in. We can setup deep links with just a minor tweak on our Flutter application.

We have to use io.supabase.flutterquickstart as the scheme. In this example, we will use login-callback as the host for our deep link, but you can change it to whatever you would like.

First, add io.supabase.flutterquickstart://login-callback/ as a new redirect URL in the Dashboard.

Supabase console deep link setting

That is it on Supabase's end and the rest are platform specific settings:

Edit the ios/Runner/Info.plist file.

Add CFBundleURLTypes to enable deep linking:

ios/Runner/Info.plist"


_20<!-- ... other tags -->
_20<plist>
_20<dict>
_20  <!-- ... other tags -->
_20
_20  <!-- Add this array for Deep Links -->
_20  <key>CFBundleURLTypes</key>
_20  <array>
_20    <dict>
_20      <key>CFBundleTypeRole</key>
_20      <string>Editor</string>
_20      <key>CFBundleURLSchemes</key>
_20      <array>
_20        <string>io.supabase.flutterquickstart</string>
_20      </array>
_20    </dict>
_20  </array>
_20  <!-- ... other tags -->
_20</dict>
_20</plist>

Main function

Now that we have deep links ready let's initialize the Supabase client inside our main function with the API credentials that you copied earlier. These variables will be exposed on the app, and that's completely fine since we have Row Level Security enabled on our Database.

lib/main.dart


_10Future<void> main() async {
_10  await Supabase.initialize(
_10    url: 'YOUR_SUPABASE_URL',
_10    anonKey: 'YOUR_SUPABASE_ANON_KEY',
_10  );
_10  runApp(MyApp());
_10}
_10
_10final supabase = Supabase.instance.client;

Set up splash screen

Let's create a splash screen that will be shown to users right after they open the app. This screen retrieves the current session and redirects the user accordingly.

lib/pages/splash_page.dart


_38import 'package:flutter/material.dart';
_38import 'package:supabase_quickstart/main.dart';
_38
_38class SplashPage extends StatefulWidget {
_38  const SplashPage({super.key});
_38
_38  @override
_38  _SplashPageState createState() => _SplashPageState();
_38}
_38
_38class _SplashPageState extends State<SplashPage> {
_38  @override
_38  void initState() {
_38    super.initState();
_38    _redirect();
_38  }
_38
_38  Future<void> _redirect() async {
_38    await Future.delayed(Duration.zero);
_38    if (!mounted) {
_38      return;
_38    }
_38
_38    final session = supabase.auth.currentSession;
_38    if (session != null) {
_38      Navigator.of(context).pushReplacementNamed('/account');
_38    } else {
_38      Navigator.of(context).pushReplacementNamed('/login');
_38    }
_38  }
_38
_38  @override
_38  Widget build(BuildContext context) {
_38    return const Scaffold(
_38      body: Center(child: CircularProgressIndicator()),
_38    );
_38  }
_38}

Let's create a Flutter widget to manage logins and sign ups. We'll use Magic Links, so users can sign in with their email without using passwords. Notice that this page sets up a listener on the user's auth state using onAuthStateChange. A new event will fire when the user comes back to the app by clicking their magic link, which this page can catch and redirect the user accordingly.

lib/pages/login_page.dart


_98import 'dart:async';
_98
_98import 'package:flutter/foundation.dart';
_98import 'package:flutter/material.dart';
_98import 'package:supabase_flutter/supabase_flutter.dart';
_98import 'package:supabase_quickstart/main.dart';
_98
_98class LoginPage extends StatefulWidget {
_98  const LoginPage({super.key});
_98
_98  @override
_98  _LoginPageState createState() => _LoginPageState();
_98}
_98
_98class _LoginPageState extends State<LoginPage> {
_98  bool _isLoading = false;
_98  bool _redirecting = false;
_98  late final TextEditingController _emailController = TextEditingController();
_98  late final StreamSubscription<AuthState> _authStateSubscription;
_98
_98  Future<void> _signIn() async {
_98    try {
_98      setState(() {
_98        _isLoading = true;
_98      });
_98      await supabase.auth.signInWithOtp(
_98        email: _emailController.text.trim(),
_98        emailRedirectTo:
_98            kIsWeb ? null : 'io.supabase.flutterquickstart://login-callback/',
_98      );
_98      if (mounted) {
_98        ScaffoldMessenger.of(context).showSnackBar(
_98          const SnackBar(content: Text('Check your email for a login link!')),
_98        );
_98        _emailController.clear();
_98      }
_98    } on AuthException catch (error) {
_98      SnackBar(
_98        content: Text(error.message),
_98        backgroundColor: Theme.of(context).colorScheme.error,
_98      );
_98    } catch (error) {
_98      SnackBar(
_98        content: const Text('Unexpected error occurred'),
_98        backgroundColor: Theme.of(context).colorScheme.error,
_98      );
_98    } finally {
_98      if (mounted) {
_98        setState(() {
_98          _isLoading = false;
_98        });
_98      }
_98    }
_98  }
_98
_98  @override
_98  void initState() {
_98    _authStateSubscription = supabase.auth.onAuthStateChange.listen((data) {
_98      if (_redirecting) return;
_98      final session = data.session;
_98      if (session != null) {
_98        _redirecting = true;
_98        Navigator.of(context).pushReplacementNamed('/account');
_98      }
_98    });
_98    super.initState();
_98  }
_98
_98  @override
_98  void dispose() {
_98    _emailController.dispose();
_98    _authStateSubscription.cancel();
_98    super.dispose();
_98  }
_98
_98  @override
_98  Widget build(BuildContext context) {
_98    return Scaffold(
_98      appBar: AppBar(title: const Text('Sign In')),
_98      body: ListView(
_98        padding: const EdgeInsets.symmetric(vertical: 18, horizontal: 12),
_98        children: [
_98          const Text('Sign in via the magic link with your email below'),
_98          const SizedBox(height: 18),
_98          TextFormField(
_98            controller: _emailController,
_98            decoration: const InputDecoration(labelText: 'Email'),
_98          ),
_98          const SizedBox(height: 18),
_98          ElevatedButton(
_98            onPressed: _isLoading ? null : _signIn,
_98            child: Text(_isLoading ? 'Loading' : 'Send Magic Link'),
_98          ),
_98        ],
_98      ),
_98    );
_98  }
_98}

Set up account page

After a user is signed in we can allow them to edit their profile details and manage their account. Let's create a new widget called account_page.dart for that.

lib/pages/account_page.dart"


_151import 'package:flutter/material.dart';
_151import 'package:supabase_flutter/supabase_flutter.dart';
_151import 'package:supabase_quickstart/main.dart';
_151
_151class AccountPage extends StatefulWidget {
_151  const AccountPage({super.key});
_151
_151  @override
_151  _AccountPageState createState() => _AccountPageState();
_151}
_151
_151class _AccountPageState extends State<AccountPage> {
_151  final _usernameController = TextEditingController();
_151  final _websiteController = TextEditingController();
_151
_151  var _loading = true;
_151
_151  /// Called once a user id is received within `onAuthenticated()`
_151  Future<void> _getProfile() async {
_151    setState(() {
_151      _loading = true;
_151    });
_151
_151    try {
_151      final userId = supabase.auth.currentUser!.id;
_151      final data =
_151          await supabase.from('profiles').select().eq('id', userId).single();
_151      _usernameController.text = (data['username'] ?? '') as String;
_151      _websiteController.text = (data['website'] ?? '') as String;
_151    } on PostgrestException catch (error) {
_151      SnackBar(
_151        content: Text(error.message),
_151        backgroundColor: Theme.of(context).colorScheme.error,
_151      );
_151    } catch (error) {
_151      SnackBar(
_151        content: const Text('Unexpected error occurred'),
_151        backgroundColor: Theme.of(context).colorScheme.error,
_151      );
_151    } finally {
_151      if (mounted) {
_151        setState(() {
_151          _loading = false;
_151        });
_151      }
_151    }
_151  }
_151
_151  /// Called when user taps `Update` button
_151  Future<void> _updateProfile() async {
_151    setState(() {
_151      _loading = true;
_151    });
_151    final userName = _usernameController.text.trim();
_151    final website = _websiteController.text.trim();
_151    final user = supabase.auth.currentUser;
_151    final updates = {
_151      'id': user!.id,
_151      'username': userName,
_151      'website': website,
_151      'updated_at': DateTime.now().toIso8601String(),
_151    };
_151    try {
_151      await supabase.from('profiles').upsert(updates);
_151      if (mounted) {
_151        const SnackBar(
_151          content: Text('Successfully updated profile!'),
_151        );
_151      }
_151    } on PostgrestException catch (error) {
_151      SnackBar(
_151        content: Text(error.message),
_151        backgroundColor: Theme.of(context).colorScheme.error,
_151      );
_151    } catch (error) {
_151      SnackBar(
_151        content: const Text('Unexpected error occurred'),
_151        backgroundColor: Theme.of(context).colorScheme.error,
_151      );
_151    } finally {
_151      if (mounted) {
_151        setState(() {
_151          _loading = false;
_151        });
_151      }
_151    }
_151  }
_151
_151  Future<void> _signOut() async {
_151    try {
_151      await supabase.auth.signOut();
_151    } on AuthException catch (error) {
_151      SnackBar(
_151        content: Text(error.message),
_151        backgroundColor: Theme.of(context).colorScheme.error,
_151      );
_151    } catch (error) {
_151      SnackBar(
_151        content: const Text('Unexpected error occurred'),
_151        backgroundColor: Theme.of(context).colorScheme.error,
_151      );
_151    } finally {
_151      if (mounted) {
_151        Navigator.of(context).pushReplacementNamed('/login');
_151      }
_151    }
_151  }
_151
_151  @override
_151  void initState() {
_151    super.initState();
_151    _getProfile();
_151  }
_151
_151  @override
_151  void dispose() {
_151    _usernameController.dispose();
_151    _websiteController.dispose();
_151    super.dispose();
_151  }
_151
_151  @override
_151  Widget build(BuildContext context) {
_151    return Scaffold(
_151      appBar: AppBar(title: const Text('Profile')),
_151      body: _loading
_151          ? const Center(child: CircularProgressIndicator())
_151          : ListView(
_151              padding: const EdgeInsets.symmetric(vertical: 18, horizontal: 12),
_151              children: [
_151                TextFormField(
_151                  controller: _usernameController,
_151                  decoration: const InputDecoration(labelText: 'User Name'),
_151                ),
_151                const SizedBox(height: 18),
_151                TextFormField(
_151                  controller: _websiteController,
_151                  decoration: const InputDecoration(labelText: 'Website'),
_151                ),
_151                const SizedBox(height: 18),
_151                ElevatedButton(
_151                  onPressed: _loading ? null : _updateProfile,
_151                  child: Text(_loading ? 'Saving...' : 'Update'),
_151                ),
_151                const SizedBox(height: 18),
_151                TextButton(onPressed: _signOut, child: const Text('Sign Out')),
_151              ],
_151            ),
_151    );
_151  }
_151}

Launch!

Now that we have all the components in place, let's update lib/main.dart:

lib/main.dart


_44import 'package:flutter/material.dart';
_44import 'package:supabase_flutter/supabase_flutter.dart';
_44import 'package:supabase_quickstart/pages/account_page.dart';
_44import 'package:supabase_quickstart/pages/login_page.dart';
_44import 'package:supabase_quickstart/pages/splash_page.dart';
_44
_44Future<void> main() async {
_44  await Supabase.initialize(
_44    url: 'YOUR_SUPABASE_URL',
_44    anonKey: 'YOUR_SUPABASE_ANON_KEY',
_44  );
_44  runApp(MyApp());
_44}
_44
_44final supabase = Supabase.instance.client;
_44
_44class MyApp extends StatelessWidget {
_44  @override
_44  Widget build(BuildContext context) {
_44    return MaterialApp(
_44      title: 'Supabase Flutter',
_44      theme: ThemeData.dark().copyWith(
_44        primaryColor: Colors.green,
_44        textButtonTheme: TextButtonThemeData(
_44          style: TextButton.styleFrom(
_44            foregroundColor: Colors.green,
_44          ),
_44        ),
_44        elevatedButtonTheme: ElevatedButtonThemeData(
_44          style: ElevatedButton.styleFrom(
_44            foregroundColor: Colors.white,
_44            backgroundColor: Colors.green,
_44          ),
_44        ),
_44      ),
_44      initialRoute: '/',
_44      routes: <String, WidgetBuilder>{
_44        '/': (_) => const SplashPage(),
_44        '/login': (_) => const LoginPage(),
_44        '/account': (_) => const AccountPage(),
_44      },
_44    );
_44  }
_44}

Once that's done, run this in a terminal window to launch on Android or iOS:


_10flutter run

Or for web, run the following command to launch it on localhost:3000


_10flutter run -d web-server --web-hostname localhost --web-port 3000

And then open the browser to localhost:3000 and you should see the completed app.

Supabase User Management example

Bonus: Profile photos

Every Supabase project is configured with Storage for managing large files like photos and videos.

Making sure we have a public bucket

We will be storing the image as a publicly sharable image. Make sure your avatars bucket is set to public, and if it is not, change the publicity by clicking the dot menu that appears when you hover over the bucket name. You should see an orange Public badge next to your bucket name if your bucket is set to public.

Adding image uploading feature to account page

We will use image_picker plugin to select an image from the device.

Add the following line in your pubspec.yaml file to install image_picker:


_10image_picker: ^1.0.5

Using image_picker requires some additional preparation depending on the platform. Follow the instruction on README.md of image_picker on how to set it up for the platform you are using.

Once you are done with all of the above, it is time to dive into coding.

Let's create an avatar for the user so that they can upload a profile photo. We can start by creating a new component:

lib/components/avatar.dart


_99import 'package:flutter/material.dart';
_99import 'package:image_picker/image_picker.dart';
_99import 'package:supabase_flutter/supabase_flutter.dart';
_99import 'package:supabase_quickstart/main.dart';
_99
_99class Avatar extends StatefulWidget {
_99  const Avatar({
_99    super.key,
_99    required this.imageUrl,
_99    required this.onUpload,
_99  });
_99
_99  final String? imageUrl;
_99  final void Function(String) onUpload;
_99
_99  @override
_99  _AvatarState createState() => _AvatarState();
_99}
_99
_99class _AvatarState extends State<Avatar> {
_99  bool _isLoading = false;
_99
_99  @override
_99  Widget build(BuildContext context) {
_99    return Column(
_99      children: [
_99        if (widget.imageUrl == null || widget.imageUrl!.isEmpty)
_99          Container(
_99            width: 150,
_99            height: 150,
_99            color: Colors.grey,
_99            child: const Center(
_99              child: Text('No Image'),
_99            ),
_99          )
_99        else
_99          Image.network(
_99            widget.imageUrl!,
_99            width: 150,
_99            height: 150,
_99            fit: BoxFit.cover,
_99          ),
_99        ElevatedButton(
_99          onPressed: _isLoading ? null : _upload,
_99          child: const Text('Upload'),
_99        ),
_99      ],
_99    );
_99  }
_99
_99  Future<void> _upload() async {
_99    final picker = ImagePicker();
_99    final imageFile = await picker.pickImage(
_99      source: ImageSource.gallery,
_99      maxWidth: 300,
_99      maxHeight: 300,
_99    );
_99    if (imageFile == null) {
_99      return;
_99    }
_99    setState(() => _isLoading = true);
_99
_99    try {
_99      final bytes = await imageFile.readAsBytes();
_99      final fileExt = imageFile.path.split('.').last;
_99      final fileName = '${DateTime.now().toIso8601String()}.$fileExt';
_99      final filePath = fileName;
_99      await supabase.storage.from('avatars').uploadBinary(
_99            filePath,
_99            bytes,
_99            fileOptions: FileOptions(contentType: imageFile.mimeType),
_99          );
_99      final imageUrlResponse = await supabase.storage
_99          .from('avatars')
_99          .createSignedUrl(filePath, 60 * 60 * 24 * 365 * 10);
_99      widget.onUpload(imageUrlResponse);
_99    } on StorageException catch (error) {
_99      if (mounted) {
_99        ScaffoldMessenger.of(context).showSnackBar(
_99          SnackBar(
_99            content: Text(error.message),
_99            backgroundColor: Theme.of(context).colorScheme.error,
_99          ),
_99        );
_99      }
_99    } catch (error) {
_99      if (mounted) {
_99        ScaffoldMessenger.of(context).showSnackBar(
_99          SnackBar(
_99            content: const Text('Unexpected error occurred'),
_99            backgroundColor: Theme.of(context).colorScheme.error,
_99          ),
_99        );
_99      }
_99    }
_99
_99    setState(() => _isLoading = false);
_99  }
_99}

And then we can add the widget to the Account page as well as some logic to update the avatar_url whenever the user uploads a new avatar.

lib/pages/account_page.dart


_195import 'package:flutter/material.dart';
_195import 'package:supabase_flutter/supabase_flutter.dart';
_195import 'package:supabase_quickstart/components/avatar.dart';
_195import 'package:supabase_quickstart/main.dart';
_195
_195class AccountPage extends StatefulWidget {
_195  const AccountPage({super.key});
_195
_195  @override
_195  _AccountPageState createState() => _AccountPageState();
_195}
_195
_195class _AccountPageState extends State<AccountPage> {
_195  final _usernameController = TextEditingController();
_195  final _websiteController = TextEditingController();
_195
_195  String? _avatarUrl;
_195  var _loading = true;
_195
_195  /// Called once a user id is received within `onAuthenticated()`
_195  Future<void> _getProfile() async {
_195    setState(() {
_195      _loading = true;
_195    });
_195
_195    try {
_195      final userId = supabase.auth.currentSession!.user.id;
_195      final data = await supabase
_195          .from('profiles')
_195          .select()
_195          .eq('id', userId)
_195          .single();
_195      _usernameController.text = (data['username'] ?? '') as String;
_195      _websiteController.text = (data['website'] ?? '') as String;
_195      _avatarUrl = (data['avatar_url'] ?? '') as String;
_195    } on PostgrestException catch (error) {
_195      SnackBar(
_195        content: Text(error.message),
_195        backgroundColor: Theme.of(context).colorScheme.error,
_195      );
_195    } catch (error) {
_195      SnackBar(
_195        content: const Text('Unexpected error occurred'),
_195        backgroundColor: Theme.of(context).colorScheme.error,
_195      );
_195    } finally {
_195      if (mounted) {
_195        setState(() {
_195          _loading = false;
_195        });
_195      }
_195    }
_195  }
_195
_195  /// Called when user taps `Update` button
_195  Future<void> _updateProfile() async {
_195    setState(() {
_195      _loading = true;
_195    });
_195    final userName = _usernameController.text.trim();
_195    final website = _websiteController.text.trim();
_195    final user = supabase.auth.currentUser;
_195    final updates = {
_195      'id': user!.id,
_195      'username': userName,
_195      'website': website,
_195      'updated_at': DateTime.now().toIso8601String(),
_195    };
_195    try {
_195      await supabase.from('profiles').upsert(updates);
_195      if (mounted) {
_195        const SnackBar(
_195          content: Text('Successfully updated profile!'),
_195        );
_195      }
_195    } on PostgrestException catch (error) {
_195      SnackBar(
_195        content: Text(error.message),
_195        backgroundColor: Theme.of(context).colorScheme.error,
_195      );
_195    } catch (error) {
_195      SnackBar(
_195        content: const Text('Unexpected error occurred'),
_195        backgroundColor: Theme.of(context).colorScheme.error,
_195      );
_195    } finally {
_195      if (mounted) {
_195        setState(() {
_195          _loading = false;
_195        });
_195      }
_195    }
_195  }
_195
_195  Future<void> _signOut() async {
_195    try {
_195      await supabase.auth.signOut();
_195    } on AuthException catch (error) {
_195      SnackBar(
_195        content: Text(error.message),
_195        backgroundColor: Theme.of(context).colorScheme.error,
_195      );
_195    } catch (error) {
_195      SnackBar(
_195        content: const Text('Unexpected error occurred'),
_195        backgroundColor: Theme.of(context).colorScheme.error,
_195      );
_195    } finally {
_195      if (mounted) {
_195        Navigator.of(context).pushReplacementNamed('/login');
_195      }
_195    }
_195  }
_195
_195  /// Called when image has been uploaded to Supabase storage from within Avatar widget
_195  Future<void> _onUpload(String imageUrl) async {
_195    try {
_195      final userId = supabase.auth.currentUser!.id;
_195      await supabase.from('profiles').upsert({
_195        'id': userId,
_195        'avatar_url': imageUrl,
_195      });
_195      if (mounted) {
_195        const SnackBar(
_195          content: Text('Updated your profile image!'),
_195        );
_195      }
_195    } on PostgrestException catch (error) {
_195      SnackBar(
_195        content: Text(error.message),
_195        backgroundColor: Theme.of(context).colorScheme.error,
_195      );
_195    } catch (error) {
_195      SnackBar(
_195        content: const Text('Unexpected error occurred'),
_195        backgroundColor: Theme.of(context).colorScheme.error,
_195      );
_195    }
_195    if (!mounted) {
_195      return;
_195    }
_195
_195    setState(() {
_195      _avatarUrl = imageUrl;
_195    });
_195  }
_195
_195  @override
_195  void initState() {
_195    super.initState();
_195    _getProfile();
_195  }
_195
_195  @override
_195  void dispose() {
_195    _usernameController.dispose();
_195    _websiteController.dispose();
_195    super.dispose();
_195  }
_195
_195  @override
_195  Widget build(BuildContext context) {
_195    return Scaffold(
_195      appBar: AppBar(title: const Text('Profile')),
_195      body: _loading
_195          ? const Center(child: CircularProgressIndicator())
_195          : ListView(
_195              padding: const EdgeInsets.symmetric(vertical: 18, horizontal: 12),
_195              children: [
_195                Avatar(
_195                  imageUrl: _avatarUrl,
_195                  onUpload: _onUpload,
_195                ),
_195                const SizedBox(height: 18),
_195                TextFormField(
_195                  controller: _usernameController,
_195                  decoration: const InputDecoration(labelText: 'User Name'),
_195                ),
_195                const SizedBox(height: 18),
_195                TextFormField(
_195                  controller: _websiteController,
_195                  decoration: const InputDecoration(labelText: 'Website'),
_195                ),
_195                const SizedBox(height: 18),
_195                ElevatedButton(
_195                  onPressed: _loading ? null : _updateProfile,
_195                  child: Text(_loading ? 'Saving...' : 'Update'),
_195                ),
_195                const SizedBox(height: 18),
_195                TextButton(onPressed: _signOut, child: const Text('Sign Out')),
_195              ],
_195            ),
_195    );
_195  }
_195}

Storage management

If you upload additional profile photos, they'll accumulate in the avatars bucket because of their random names with only the latest being referenced from public.profiles and the older versions getting orphaned.

To automatically remove obsolete storage objects, extend the database triggers. Note that it is not sufficient to delete the objects from the storage.objects table because that would orphan and leak the actual storage objects in the S3 backend. Instead, invoke the storage API within Postgres via the http extension.

Enable the http extension for the extensions schema in the Dashboard. Then, define the following SQL functions in the SQL Editor to delete storage objects via the API:


_34create or replace function delete_storage_object(bucket text, object text, out status int, out content text)
_34returns record
_34language 'plpgsql'
_34security definer
_34as $$
_34declare
_34  project_url text := '<YOURPROJECTURL>';
_34  service_role_key text := '<YOURSERVICEROLEKEY>'; --  full access needed
_34  url text := project_url||'/storage/v1/object/'||bucket||'/'||object;
_34begin
_34  select
_34      into status, content
_34           result.status::int, result.content::text
_34      FROM extensions.http((
_34    'DELETE',
_34    url,
_34    ARRAY[extensions.http_header('authorization','Bearer '||service_role_key)],
_34    NULL,
_34    NULL)::extensions.http_request) as result;
_34end;
_34$$;
_34
_34create or replace function delete_avatar(avatar_url text, out status int, out content text)
_34returns record
_34language 'plpgsql'
_34security definer
_34as $$
_34begin
_34  select
_34      into status, content
_34           result.status, result.content
_34      from public.delete_storage_object('avatars', avatar_url) as result;
_34end;
_34$$;

Next, add a trigger that removes any obsolete avatar whenever the profile is updated or deleted:


_32create or replace function delete_old_avatar()
_32returns trigger
_32language 'plpgsql'
_32security definer
_32as $$
_32declare
_32  status int;
_32  content text;
_32  avatar_name text;
_32begin
_32  if coalesce(old.avatar_url, '') <> ''
_32      and (tg_op = 'DELETE' or (old.avatar_url <> coalesce(new.avatar_url, ''))) then
_32    -- extract avatar name
_32    avatar_name := old.avatar_url;
_32    select
_32      into status, content
_32      result.status, result.content
_32      from public.delete_avatar(avatar_name) as result;
_32    if status <> 200 then
_32      raise warning 'Could not delete avatar: % %', status, content;
_32    end if;
_32  end if;
_32  if tg_op = 'DELETE' then
_32    return old;
_32  end if;
_32  return new;
_32end;
_32$$;
_32
_32create trigger before_profile_changes
_32  before update of avatar_url or delete on public.profiles
_32  for each row execute function public.delete_old_avatar();

Finally, delete the public.profile row before a user is deleted. If this step is omitted, you won't be able to delete users without first manually deleting their avatar image.


_14create or replace function delete_old_profile()
_14returns trigger
_14language 'plpgsql'
_14security definer
_14as $$
_14begin
_14  delete from public.profiles where id = old.id;
_14  return old;
_14end;
_14$$;
_14
_14create trigger before_delete_user
_14  before delete on auth.users
_14  for each row execute function public.delete_old_profile();

Congratulations, you've built a fully functional user management app using Flutter and Supabase!

Product

Data API

Development Cycle

Client Library Reference

Resources

Build a User Management App with Flutter

Project setup

Create a project

Set up the database schema

Get the API Keys

Building the app

Initialize a Flutter app

Setup deep links

Main function

Set up splash screen

Set up account page

Launch!

Bonus: Profile photos

Making sure we have a public bucket

Adding image uploading feature to account page

Create an upload widget

Add the new widget

Storage management

See also

Build a User Management App with Flutter

Project setup#

Create a project#

Set up the database schema#

Get the API Keys#

Building the app#

Initialize a Flutter app#

Setup deep links#

Main function#

Set up splash screen#

Set up a login page#

Set up account page#

Launch!#

Bonus: Profile photos#

Making sure we have a public bucket#

Adding image uploading feature to account page#

Create an upload widget#

Add the new widget#

Storage management#

See also#

Project setup

Create a project

Set up the database schema

Get the API Keys

Building the app

Initialize a Flutter app

Setup deep links

Main function

Set up splash screen

Set up a login page

Set up account page

Launch!

Bonus: Profile photos

Making sure we have a public bucket

Adding image uploading feature to account page

Create an upload widget

Add the new widget

Storage management

See also