supabase_flutter 1.4.1

Flutter integration for Supabase. This package makes it simple for developers to build secure and scalable products.

supabase_flutter

---

Flutter Client library for Supabase.

• Documentation: https://supabase.com/docs/reference/dart/introduction

Getting Started

Import the package:

import 'package:supabase_flutter/supabase_flutter.dart';

Initialize Supabase before using it:

import 'package:supabase_flutter/supabase_flutter.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  await Supabase.initialize(
    url: SUPABASE_URL,
    anonKey: SUPABASE_ANON_KEY,
  );

  runApp(MyApp());
}

// It's handy to then extract the Supabase client in a variable for later uses
final supabase = Supabase.instance.client;

authCallbackUrlHostname is optional. It will be used to filter Supabase authentication redirect deeplink. You need to provide this param if you use deeplink for other features on the app.

debug is optional. It's enabled by default if you're running the app in debug mode (flutter run --debug).

Usage example

Authentication

import 'package:supabase_flutter/supabase_flutter.dart';

final supabase = Supabase.instance.client;

class MyWidget extends StatefulWidget {
  const MyWidget({Key? key}) : super(key: key);

  @override
  State<MyWidget> createState() => _MyWidgetState();
}

class _MyWidgetState extends State<MyWidget> {
  late final StreamSubscription<AuthState> _authSubscription;
  User? _user;

  @override
  void initState() {
    _authSubscription = supabase.auth.onAuthStateChange.listen((data) {
      final AuthChangeEvent event = data.event;
      final Session? session = data.session;
      setState(() {
        _user = session?.user;
      });
    });
    super.initState();
  }

  @override
  void dispose() {
    _authSubscription.cancel();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return ElevatedButton(
      onPressed: () {
        supabase.auth.signInWithOtp(email: '[e-mail]');
      },
      child: const Text('Login'),
    );
  }
}

Database

import 'package:supabase_flutter/supabase_flutter.dart';

final supabase = Supabase.instance.client;

class MyWidget extends StatefulWidget {
  const MyWidget({Key? key}) : super(key: key);

  @override
  State<MyWidget> createState() => _MyWidgetState();
}

class _MyWidgetState extends State<MyWidget> {
  // Persisting the future as local variable to prevent refetching upon rebuilds. 
  final Future<dynamic> _future = supabase
      .from('countries')
      .select()
      .order('name', ascending: true);

  @override
  Widget build(BuildContext context) {
    return FutureBuilder(
      future: _future,
      builder: (context, snapshot) {
        // return your widget with the data from snapshot
      },
    );
  }
}

Realtime

Realtime data as Stream

To receive realtime updates, you have to first enable Realtime on from your Supabase console. You can read more here on how to enable it.

Warning When using stream() with a StreamBuilder, make sure to persist the stream value as a variable in a StatefulWidget instead of directly constructing the stream within your widget tree, which could cause rapid rebuilds that will lead to losing realtime connection.

import 'package:supabase_flutter/supabase_flutter.dart';

final supabase = Supabase.instance.client;

class MyWidget extends StatefulWidget {
  const MyWidget({Key? key}) : super(key: key);

  @override
  State<MyWidget> createState() => _MyWidgetState();
}

class _MyWidgetState extends State<MyWidget> {
  // Persisting the future as local variable to prevent refetching upon rebuilds.
  final List<Map<String, dynamic>> _stream = supabase.from('countries').stream(primaryKey: ['id']);

  @override
  Widget build(BuildContext context) {
    return StreamBuilder<List<Map<String, dynamic>>>(
      stream: _stream,
      builder: (context, snapshot) {
        // return your widget with the data from snapshot
      },
    );
  }
}

Postgres Changes

You can get notified whenever there is a change in your Supabase tables.

final myChannel = supabase.channel('my_channel');

myChannel.on(
    RealtimeListenTypes.postgresChanges,
    ChannelFilter(
      event: '*',
      schema: 'public',
      table: 'countries',
    ), (payload, [ref]) {
  // Do something fun or interesting when there is an change on the database
}).subscribe();

Broadcast

Broadcast lets you send and receive low latency messages between connected clients without bypassing the database.

final myChannel = supabase.channel('my_channel');

// Subscribe to `cursor-pos` broadcast event
myChannel.on(RealtimeListenTypes.broadcast,
    ChannelFilter(event: 'cursor-pos'), (payload, [ref]) {
  // Do something fun or interesting when there is an change on the database
}).subscribe();

// Send a broadcast message to other connected clients
await myChannel.send(
  type: RealtimeListenTypes.broadcast,
  event: 'cursor-pos',
  payload: {'x': 30, 'y': 50},
);

Presence

Presence let's you easily create "I'm online" feature.

final myChannel = supabase.channel('my_channel');

// Subscribe to presence events
myChannel.on(
    RealtimeListenTypes.presence, ChannelFilter(event: 'sync'),
    (payload, [ref]) {
  final onlineUsers = myChannel.presenceState();
  // handle sync event
}).on(RealtimeListenTypes.presence, ChannelFilter(event: 'join'),
    (payload, [ref]) {
  // New users have joined
}).on(RealtimeListenTypes.presence, ChannelFilter(event: 'leave'),
    (payload, [ref]) {
  // Users have left
}).subscribe(((status, [_]) async {
  if (status == 'SUBSCRIBED') {
    // Send the current user's state upon subscribing
    final status = await myChannel
        .track({'online_at': DateTime.now().toIso8601String()});
  }
}));

Storage

import 'package:supabase_flutter/supabase_flutter.dart';

final supabase = Supabase.instance.client;

class MyWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return ElevatedButton(
      onPressed: () {
        final file = File('example.txt');
        file.writeAsStringSync('File content');
        supabase.storage
            .from('my_bucket')
            .upload('my/path/to/files/example.txt', file);
      },
      child: const Text('Upload'),
    );
  }
}

Edge Functions

import 'package:supabase_flutter/supabase_flutter.dart';

final client = Supabase.instance.client;

class MyWidget extends StatefulWidget {
  const MyWidget({Key? key}) : super(key: key);

  @override
  State<MyWidget> createState() => _MyWidgetState();
}

class _MyWidgetState extends State<MyWidget> {
  // Persisting the future as local variable to prevent refetching upon rebuilds.
  final _future = client.functions.invoke('get_countries');

  @override
  Widget build(BuildContext context) {
    return FutureBuilder(
      future: _future,
      builder: (context, snapshot) {
        // return your widget with the data from snapshot
      },
    );
  }
}

Authentication Deep Dive

Using this package automatically persists the auth state on local storage. It also helps you handle authentication with deep link from 3rd party service like Google, Github, Twitter...

Email authentication

import 'package:supabase_flutter/supabase_flutter.dart';

Future<void> signIn(String email, String password) async {
  final response = await Supabase.instance.client.auth.signInWithPassword(email: email, password: password);
  final Session? session = response.session;
  final User? user = response.user;
}

signInWithProvider

This method will automatically launch the auth url and open a browser for user to sign in with 3rd party login.

supabase.auth.signInWithOAuth(
  Provider.google,
  redirectTo: 'io.supabase.flutter://reset-callback/',
);

Custom LocalStorage

As default, supabase_flutter uses hive to persist the user session. Encryption is disabled by default, since an unique encryption key is necessary, and we can not define it. To set an encryptionKey, do the following:

Future<void> main() async {
  // set it before initializing
  HiveLocalStorage.encryptionKey = 'my_secure_key';
  await Supabase.initialize(...);
}

Note the key must be the same. There is no check if the encryption key is correct. If it isn't, there may be unexpected behavior. Learn more about encryption in hive.

However you can use any other methods by creating a LocalStorage implementation. For example, we can use flutter_secure_storage plugin to store the user session in a secure storage.

// Define the custom LocalStorage implementation
class SecureLocalStorage extends LocalStorage {
  SecureLocalStorage() : super(
    initialize: () async {},
    hasAccessToken: () {
      const storage = FlutterSecureStorage();
      return storage.containsKey(key: supabasePersistSessionKey);
    }, accessToken: () {
      const storage = FlutterSecureStorage();
      return storage.read(key: supabasePersistSessionKey);
    }, removePersistedSession: () {
      const storage = FlutterSecureStorage();
      return storage.delete(key: supabasePersistSessionKey);
    }, persistSession: (String value) {
      const storage = FlutterSecureStorage();
      return storage.write(key: supabasePersistSessionKey, value: value);
    },
  );
}

// use it when initializing
Supabase.initialize(
  ...
  localStorage: SecureLocalStorage(),
);

You can also use EmptyLocalStorage to disable session persistence:

Supabase.initialize(
  // ...
  localStorage: const EmptyLocalStorage(),
);

Deep link config

*Currently supabase_flutter supports deep links on Android, iOS, Web, MacOS and Windows.

Supabase redirect URLs config

• Go to your Supabase project Authentication Settings page.
• You need to enter your app redirect callback on Additional Redirect URLs field.

The redirect callback url should have this format [YOUR_SCHEME]://[YOUR_AUTH_HOSTNAME]

Supabase 3rd party logins config

Follow the guide https://supabase.io/docs/guides/auth#third-party-logins

For Android

How to setup

Deep Links can have any custom scheme. The downside is that any app can claim a scheme, so make sure yours are as unique as possible, eg. HST0000001://host.com.

<manifest ...>
  <!-- ... other tags -->
  <application ...>
    <activity ...>
      <!-- ... other tags -->

      <!-- Deep Links -->
      <intent-filter>
        <action android:name="android.intent.action.VIEW" />
        <category android:name="android.intent.category.DEFAULT" />
        <category android:name="android.intent.category.BROWSABLE" />
        <!-- Accepts URIs that begin with YOUR_SCHEME://YOUR_HOST -->
        <data
          android:scheme="[YOUR_SCHEME]"
          android:host="[YOUR_HOST]" />
      </intent-filter>
    </activity>
  </application>
</manifest>

The android:host attribute is optional for Deep Links.

For more info: https://developer.android.com/training/app-links/deep-linking

For iOS

How to setup

Custom URL schemes can have... any custom scheme and there is no host specificity, nor entitlements or a hosted file. The downside is that any app can claim any scheme, so make sure yours is as unique as possible, eg. hst0000001 or myIncrediblyAwesomeScheme.

For Custom URL schemes you need to declare the scheme in ios/Runner/Info.plist (or through Xcode's Target Info editor, under URL Types):

<!-- ... other tags -->
<plist>
<dict>
  <!-- ... other tags -->
  <key>CFBundleURLTypes</key>
  <array>
    <dict>
      <key>CFBundleTypeRole</key>
      <string>Editor</string>
      <key>CFBundleURLSchemes</key>
      <array>
        <string>[YOUR_SCHEME]</string>
      </array>
    </dict>
  </array>
  <!-- ... other tags -->
</dict>
</plist>

This allows for your app to be started from YOUR_SCHEME://ANYTHING links.

For more info: https://developer.apple.com/documentation/xcode/defining-a-custom-url-scheme-for-your-app

For Windows

How to setup

Setting up deep links in Windows has few more steps than other platforms. Learn more

Declare this method in <PROJECT_DIR>\windows\runner\win32_window.h

  // Dispatches link if any.
  // This method enables our app to be with a single instance too.
  // This is optional but mandatory if you want to catch further links in same app.
  bool SendAppLinkToInstance(const std::wstring& title);

Add this inclusion at the top of <PROJECT_DIR>\windows\runner\win32_window.cpp

#include "app_links_windows/app_links_windows_plugin.h"

Add this method in <PROJECT_DIR>\windows\runner\win32_window.cpp

bool Win32Window::SendAppLinkToInstance(const std::wstring& title) {
  // Find our exact window
  HWND hwnd = ::FindWindow(kWindowClassName, title.c_str());
  
  if (hwnd) {
    // Dispatch new link to current window
    SendAppLink(hwnd);

    // (Optional) Restore our window to front in same state
    WINDOWPLACEMENT place = { sizeof(WINDOWPLACEMENT) };
    GetWindowPlacement(hwnd, &place);
    switch(place.showCmd) {
      case SW_SHOWMAXIMIZED:
          ShowWindow(hwnd, SW_SHOWMAXIMIZED);
          break;
      case SW_SHOWMINIMIZED:
          ShowWindow(hwnd, SW_RESTORE);
          break;
      default:
          ShowWindow(hwnd, SW_NORMAL);
          break;
    }
    SetWindowPos(0, HWND_TOP, 0, 0, 0, 0, SWP_SHOWWINDOW | SWP_NOSIZE | SWP_NOMOVE);
    SetForegroundWindow(hwnd);
    // END Restore

    // Window has been found, don't create another one.
    return true;
  }

  return false;
}

Add the call to the previous method in CreateAndShow

bool Win32Window::CreateAndShow(const std::wstring& title,
                                const Point& origin,
                                const Size& size) {
if (SendAppLinkToInstance(title)) {
    return false;
}

...

At this point, you can register your own scheme.
On Windows, URL protocols are setup in the Windows registry.

This package won't do it for you.

You can achieve it with url_protocol inside you app.

The most relevant solution is to include those registry modifications into your installer to allow for deregistration.

For Mac OS

How to setup

Add this XML chapter in your macos/Runner/Info.plist inside

<!-- ... other tags -->
<plist version="1.0">
<dict>
  <!-- ... other tags -->
  <key>CFBundleURLTypes</key>
  <array>
      <dict>
          <key>CFBundleURLName</key>
          <!-- abstract name for this URL type (you can leave it blank) -->
          <string>sample_name</string>
          <key>CFBundleURLSchemes</key>
          <array>
              <!-- your schemes -->
              <string>sample</string>
          </array>
      </dict>
  </array>
  <!-- ... other tags -->
</dict>
</plist>

---

Contributing

• Fork the repo on GitHub
• Clone the project to your own machine
• Commit changes to your own branch
• Push your work back up to your fork
• Submit a Pull request so that we can review your changes and merge

License

This repo is licenced under MIT.

Resources

• Quickstart: Flutter
• Flutter Tutorial: building a Flutter chat app
• Flutter Tutorial - Part 2: Authentication and Authorization with RLS