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Build a Social Sign-in App with Expo React Native

还没翻译译自英文（supabase.com）本页 122 段都还没译

This tutorial demonstrates how to build a React Native app with Expo that implements social sign-in. The app showcases a complete authentication flow with protected navigation using:

  • Supabase Database - a Postgres database for storing your user data with Row Level Security to ensure data is protected and users can only access their own information.
  • Supabase Auth - enables users to sign in through social sign-in providers (Apple and Google).

The app's login screen in a web browser, an Android emulator, and an iPhone simulator. Each screen shows the Supabase logo, a Login heading, and buttons to sign in with Apple and Google.

Note

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

Project setup

Before you start building you need to set up the Database and API. You can do this by starting a new Project in Supabase and then creating a "schema" inside the database.

Create a project

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

Set up the database schema

Now set up the database schema. You can use the "User Management Starter" quickstart in the SQL Editor, or you can copy/paste the SQL from below and run it.

DashboardSQL

  1. Go to the SQL Editor page in the Dashboard.
  2. Click User Management Starter under the Reference > Examples tab.
  3. Click Run.

Note

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

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

Get API details

To interact with data in database tables, you use the client libraries that wrap the auto-generated Data API endpoints, authenticating using the Project URL and key from the project Connect dialog.

Project URL: https://<project-ref>.supabase.co (find yours in the dashboard)

Publishable key: sb_publishable_... (find yours in the dashboard)

Note

See API keys for a full explanation of all key types, their uses, and where to find them.

Building the app

Start by building the React Native app from scratch.

Initialize a React Native app

Use Expo to initialize an app called expo-social-auth with the standard template:

npx create-expo-app@latest

cd expo-social-auth

Install the additional dependencies:

npx expo install @supabase/supabase-js @react-native-async-storage/async-storage expo-secure-store expo-splash-screen

Now, create a helper file to initialize the Supabase client for both web and React Native platforms using platform-specific storage adapters: Expo SecureStore for mobile and AsyncStorage for web.

AsyncStorageSecureStore

import AsyncStorage from '@react-native-async-storage/async-storage'
import { createClient } from '@supabase/supabase-js'
import 'react-native-url-polyfill/auto'

const isSSR = typeof window === 'undefined'

const ExpoWebSecureStoreAdapter = {
  getItem: (key: string) => {
    if (isSSR) return null
    console.debug('getItem', { key })
    return AsyncStorage.getItem(key)
  },
  setItem: (key: string, value: string) => {
    if (isSSR) return
    return AsyncStorage.setItem(key, value)
  },
  removeItem: (key: string) => {
    if (isSSR) return
    return AsyncStorage.removeItem(key)
  },
}

export const supabase = createClient(
  process.env.EXPO_PUBLIC_SUPABASE_URL ?? '',
  process.env.EXPO_PUBLIC_SUPABASE_PUBLISHABLE_KEY ?? '',
  {
    auth: {
      storage: ExpoWebSecureStoreAdapter,
      autoRefreshToken: true,
      persistSession: true,
      detectSessionInUrl: false,
    },
  }
)

Set up environment variables

You need the API URL and the publishable key copied earlier. These variables are safe to expose in your Expo app since Supabase has Row Level Security enabled on your database.

Create a .env file containing these variables:

EXPO_PUBLIC_SUPABASE_URL=""
EXPO_PUBLIC_SUPABASE_PUBLISHABLE_KEY=""
EXPO_PUBLIC_APPLE_AUTH_SERVICE_ID=""
EXPO_PUBLIC_APPLE_AUTH_REDIRECT_URI=""
EXPO_PUBLIC_GOOGLE_AUTH_WEB_CLIENT_ID=""

Set up protected navigation

Next, you need to protect app navigation to prevent unauthenticated users from accessing protected routes. Use the Expo SplashScreen to display a loading screen while fetching the user profile and verifying authentication status.

Create the AuthContext

Create a React context to manage the authentication session, making it accessible from any component:

import { createContext, useContext } from 'react'

export type AuthData = {
  claims?: Record<string, any> | null
  profile?: any | null
  isLoading: boolean
  isLoggedIn: boolean
}

export const AuthContext = createContext<AuthData>({
  claims: undefined,
  profile: undefined,
  isLoading: true,
  isLoggedIn: false,
})

export const useAuthContext = () => useContext(AuthContext)

Create the AuthProvider

Next, create a provider component to manage the authentication session throughout the app:

import { AuthContext } from '@/hooks/use-auth-context'
import { supabase } from '@/lib/supabase'
import { PropsWithChildren, useEffect, useState } from 'react'

export default function AuthProvider({ children }: PropsWithChildren) {
  const [claims, setClaims] = useState<Record<string, any> | undefined | null>()
  const [profile, setProfile] = useState<any>()
  const [isLoading, setIsLoading] = useState<boolean>(true)

  // Fetch the claims once, and subscribe to auth state changes
  useEffect(() => {
    const fetchClaims = async () => {
      setIsLoading(true)

      const { data, error } = await supabase.auth.getClaims()

      if (error) {
        console.error('Error fetching claims:', error)
      }

      setClaims(data?.claims ?? null)
      setIsLoading(false)
    }

    fetchClaims()

    const {
      data: { subscription },
    } = supabase.auth.onAuthStateChange(async (_event, _session) => {
      console.log('Auth state changed:', { event: _event })
      const { data } = await supabase.auth.getClaims()
      setClaims(data?.claims ?? null)
    })

    // Cleanup subscription on unmount
    return () => {
      subscription.unsubscribe()
    }
  }, [])

  // Fetch the profile when the claims change
  useEffect(() => {
    const fetchProfile = async () => {
      setIsLoading(true)

      if (claims) {
        const { data } = await supabase.from('profiles').select('*').eq('id', claims.sub).single()

        setProfile(data)
      } else {
        setProfile(null)
      }

      setIsLoading(false)
    }

    fetchProfile()
  }, [claims])

  return (
    <AuthContext.Provider
      value={{
        claims,
        isLoading,
        profile,
        isLoggedIn: claims != undefined,
      }}
    >
      {children}
    </AuthContext.Provider>
  )
}

Create the SplashScreenController

Create a SplashScreenController component to display the Expo SplashScreen while the authentication session is loading:

import { useAuthContext } from '@/hooks/use-auth-context'
import { SplashScreen } from 'expo-router'

SplashScreen.preventAutoHideAsync()

export function SplashScreenController() {
  const { isLoading } = useAuthContext()

  if (!isLoading) {
    SplashScreen.hideAsync()
  }

  return null
}

Create a sign-out component

Create a sign-out button component to handle user sign-out:

import { supabase } from '@/lib/supabase'
import React from 'react'
import { Button } from 'react-native'

async function onSignOutButtonPress() {
  const { error } = await supabase.auth.signOut()

  if (error) {
    console.error('Error signing out:', error)
  }
}

export default function SignOutButton() {
  return <Button title="Sign out" onPress={onSignOutButtonPress} />
}

And add it to the app/(tabs)/index.tsx file used to display the user profile data and the sign-out button:

import { Image } from 'expo-image'
import { StyleSheet } from 'react-native'

import { HelloWave } from '@/components/hello-wave'
import ParallaxScrollView from '@/components/parallax-scroll-view'
import { ThemedText } from '@/components/themed-text'
import { ThemedView } from '@/components/themed-view'
import SignOutButton from '@/components/social-auth-buttons/sign-out-button'
import { useAuthContext } from '@/hooks/use-auth-context'

export default function HomeScreen() {
  const { profile } = useAuthContext()

  return (
    <ParallaxScrollView
      headerBackgroundColor={{ light: '#A1CEDC', dark: '#1D3D47' }}
      headerImage={
        <Image
          source={require('@/assets/images/partial-react-logo.png')}
          style={styles.reactLogo}
        />
      }
    >
      <ThemedView style={styles.titleContainer}>
        <ThemedText type="title">Welcome!</ThemedText>
        <HelloWave />
      </ThemedView>
      <ThemedView style={styles.stepContainer}>
        <ThemedText type="subtitle">Username</ThemedText>
        <ThemedText>{profile?.username}</ThemedText>
        <ThemedText type="subtitle">Full name</ThemedText>
        <ThemedText>{profile?.full_name}</ThemedText>
      </ThemedView>
      <SignOutButton />
    </ParallaxScrollView>
  )
}

const styles = StyleSheet.create({
  titleContainer: {
    flexDirection: 'row',
    alignItems: 'center',
    gap: 8,
  },
  stepContainer: {
    gap: 8,
    marginBottom: 8,
  },
  reactLogo: {
    height: 178,
    width: 290,
    bottom: 0,
    left: 0,
    position: 'absolute',
  },
})

Create a sign-in screen

Next, create a basic sign-in screen component:

import { Link, Stack } from 'expo-router'
import { StyleSheet } from 'react-native'

import { ThemedText } from '@/components/themed-text'
import { ThemedView } from '@/components/themed-view'

export default function LoginScreen() {
  return (
    <>
      <Stack.Screen options={{ title: 'Login' }} />
      <ThemedView style={styles.container}>
        <ThemedText type="title">Login</ThemedText>
        <Link href="/" style={styles.link}>
          <ThemedText type="link">Try to navigate to home screen!</ThemedText>
        </Link>
      </ThemedView>
    </>
  )
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    alignItems: 'center',
    justifyContent: 'center',
    padding: 20,
  },
  link: {
    marginTop: 15,
    paddingVertical: 15,
  },
})

Implement protected routes

Wrap the navigation with the AuthProvider and SplashScreenController.

Using Expo Router's protected routes, you can secure navigation:

import { DarkTheme, DefaultTheme, ThemeProvider } from '@react-navigation/native'
import { Stack } from 'expo-router'
import { StatusBar } from 'expo-status-bar'
import 'react-native-reanimated'

import { SplashScreenController } from '@/components/splash-screen-controller'

import { useAuthContext } from '@/hooks/use-auth-context'
import { useColorScheme } from '@/hooks/use-color-scheme'
import AuthProvider from '@/providers/auth-provider'

// Separate RootNavigator so we can access the AuthContext
function RootNavigator() {
  const { isLoggedIn } = useAuthContext()

  return (
    <Stack>
      <Stack.Protected guard={isLoggedIn}>
        <Stack.Screen name="(tabs)" options={{ headerShown: false }} />
      </Stack.Protected>
      <Stack.Protected guard={!isLoggedIn}>
        <Stack.Screen name="login" options={{ headerShown: false }} />
      </Stack.Protected>
      <Stack.Screen name="+not-found" />
    </Stack>
  )
}

export default function RootLayout() {
  const colorScheme = useColorScheme()

  return (
    <ThemeProvider value={colorScheme === 'dark' ? DarkTheme : DefaultTheme}>
      <AuthProvider>
        <SplashScreenController />
        <RootNavigator />
        <StatusBar style="auto" />
      </AuthProvider>
    </ThemeProvider>
  )
}

You can now test the app by running:

npx expo prebuild
npx expo start --clear

Verify that the app works as expected. The splash screen displays while fetching the user profile, and the sign-in page appears even when attempting to navigate to the home screen using the Link button.

Note

By default Supabase Auth requires email verification before a session is created for the user. To support email verification you need to implement deep link handling!

While testing, you can disable email confirmation in your project's email auth provider settings.

Integrate social sign-in

Now integrate social sign-in with Supabase Auth, starting with Apple authentication. If you only need to implement Google authentication, you can skip to the Google authentication section.

Apple authentication

Start by adding the button inside the sign-in screen:

app/login.tsx

…
import AppleSignInButton from '@/components/social-auth-buttons/apple/apple-sign-in-button';
…
export default function LoginScreen() {
  return (
    <>
      <Stack.Screen options={{ title: 'Login' }} />
      <ThemedView style={styles.container}>
        …
        <AppleSignInButton />
        …
      </ThemedView>
    </>
  );
}
…

For Apple authentication, you can choose between:

For either option, you need to obtain a Service ID from the Apple Developer Console.

Note

To enable Apple sign-up on Android and Web, you also need to register the tunnelled URL (e.g., https://arnrer1-anonymous-8081.exp.direct) obtained by running:

npx expo start --tunnel

And add it to the Redirect URLs field in your Supabase dashboard Authentication configuration.

For more information, follow the Supabase Sign in with Apple guide.

InvertaseWebExpo

Prerequisites

Before proceeding, ensure you have followed the Invertase prerequisites documented in the Invertase Initial Setup Guide and the Invertase Android Setup Guide.

You need to add two new environment variables to the .env file:

EXPO_PUBLIC_APPLE_AUTH_SERVICE_ID="YOUR_APPLE_AUTH_SERVICE_ID"
EXPO_PUBLIC_APPLE_AUTH_REDIRECT_URI="YOUR_APPLE_AUTH_REDIRECT_URI"

iOS

Install the @invertase/react-native-apple-authentication library:

npx expo install @invertase/react-native-apple-authentication

Then create the iOS specific button component AppleSignInButton:

import { supabase } from '@/lib/supabase'
import { AppleButton, appleAuth } from '@invertase/react-native-apple-authentication'
import type { SignInWithIdTokenCredentials } from '@supabase/supabase-js'
import { router } from 'expo-router'
import { Platform } from 'react-native'

async function onAppleButtonPress() {
  // Performs login request
  const appleAuthRequestResponse = await appleAuth.performRequest({
    requestedOperation: appleAuth.Operation.LOGIN,
    // Note: it appears putting FULL_NAME first is important, see issue #293
    requestedScopes: [appleAuth.Scope.FULL_NAME, appleAuth.Scope.EMAIL],
  })

  // Get the current authentication state for user
  // Note: This method must be tested on a real device. On the iOS simulator it always throws an error.
  const credentialState = await appleAuth.getCredentialStateForUser(appleAuthRequestResponse.user)

  console.log('Apple sign in successful:', { credentialState, appleAuthRequestResponse })

  if (
    credentialState === appleAuth.State.AUTHORIZED &&
    appleAuthRequestResponse.identityToken &&
    appleAuthRequestResponse.authorizationCode
  ) {
    const signInWithIdTokenCredentials: SignInWithIdTokenCredentials = {
      provider: 'apple',
      token: appleAuthRequestResponse.identityToken,
      nonce: appleAuthRequestResponse.nonce,
      access_token: appleAuthRequestResponse.authorizationCode,
    }

    const { data, error } = await supabase.auth.signInWithIdToken(signInWithIdTokenCredentials)

    if (error) {
      console.error('Error signing in with Apple:', error)
    }

    if (data) {
      console.log('Apple sign in successful:', data)
      router.navigate('/(tabs)')
    }
  }
}

export default function AppleSignInButton() {
  if (Platform.OS !== 'ios') {
    return <></>
  }

  return (
    <AppleButton
      buttonStyle={AppleButton.Style.BLACK}
      buttonType={AppleButton.Type.SIGN_IN}
      style={{ width: 160, height: 45 }}
      onPress={() => onAppleButtonPress()}
    />
  )
}

Note

To test functionality on the simulator, remove the getCredentialStateForUser check:

components/social-auth-buttons/apple/apple-sign-in-button.ios.tsx

…
const credentialState = await appleAuth.getCredentialStateForUser(appleAuthRequestResponse.user);
…

Enable the Apple authentication capability in iOS:

json

{
  "expo": {
    …
    "ios": {
      …
      "usesAppleSignIn": true
      …
    },
    …
  }
}

Add the capabilities to the Info.plist file by following the Expo documentation.

Note

Before testing the app, if you've already built the iOS app, clean the project artifacts:

npx react-native-clean-project clean-project-auto

If issues persist, try completely cleaning the cache, as reported by many users in this closed issue.

Finally, update the iOS project by installing the Pod library and running the Expo prebuild command:

cd ios
pod install
cd ..
npx expo prebuild

Now test the application on a physical device:

npx expo run:ios --no-build-cache --device

You should see the sign-in screen with the Apple authentication button.

Note

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

Android

Install the required libraries:

npx expo install @invertase/react-native-apple-authentication react-native-get-random-values uuid

Next, create the Android-specific AppleSignInButton component:

import { supabase } from '@/lib/supabase'
import { appleAuthAndroid, AppleButton } from '@invertase/react-native-apple-authentication'
import { SignInWithIdTokenCredentials } from '@supabase/supabase-js'
import { Platform } from 'react-native'
import 'react-native-get-random-values'
import { v4 as uuid } from 'uuid'

async function onAppleButtonPress() {
  // Generate secure, random values for state and nonce
  const rawNonce = uuid()
  const state = uuid()

  // Configure the request
  appleAuthAndroid.configure({
    // The Service ID you registered with Apple
    clientId: process.env.EXPO_PUBLIC_APPLE_AUTH_SERVICE_ID ?? '',

    // Return URL added to your Apple dev console. We intercept this redirect, but it must still match
    // the URL you provided to Apple. It can be an empty route on your backend as it's never called.
    redirectUri: process.env.EXPO_PUBLIC_APPLE_AUTH_REDIRECT_URI ?? '',

    // The type of response requested - code, id_token, or both.
    responseType: appleAuthAndroid.ResponseType.ALL,

    // The amount of user information requested from Apple.
    scope: appleAuthAndroid.Scope.ALL,

    // Random nonce value that will be SHA256 hashed before sending to Apple.
    nonce: rawNonce,

    // Unique state value used to prevent CSRF attacks. A UUID will be generated if nothing is provided.
    state,
  })

  // Open the browser window for user sign in
  const credentialState = await appleAuthAndroid.signIn()
  console.log('Apple sign in successful:', credentialState)

  if (credentialState.id_token && credentialState.code && credentialState.nonce) {
    const signInWithIdTokenCredentials: SignInWithIdTokenCredentials = {
      provider: 'apple',
      token: credentialState.id_token,
      nonce: credentialState.nonce,
      access_token: credentialState.code,
    }

    const { data, error } = await supabase.auth.signInWithIdToken(signInWithIdTokenCredentials)

    if (error) {
      console.error('Error signing in with Apple:', error)
    }

    if (data) {
      console.log('Apple sign in successful:', data)
    }
  }
}

export default function AppleSignInButton() {
  if (Platform.OS !== 'android' || appleAuthAndroid.isSupported !== true) {
    return <></>
  }

  return (
    <AppleButton
      buttonStyle={AppleButton.Style.BLACK}
      buttonType={AppleButton.Type.SIGN_IN}
      onPress={() => onAppleButtonPress()}
    />
  )
}

You should now be able to test the authentication by running it on a physical device or simulator:

npx expo run:android --no-build-cache

Google authentication

Start by adding the button to the sign-in screen:

app/login.tsx

…
import GoogleSignInButton from '@/components/social-auth-buttons/google/google-sign-in-button';
…
export default function LoginScreen() {
  return (
    <>
      <Stack.Screen options={{ title: 'Login' }} />
      <ThemedView style={styles.container}>
        …
        <GoogleSignInButton />
        …
      </ThemedView>
    </>
  );
}
…

For Google authentication, you can choose between the following options:

Note

The GN Google Sign In Free doesn't support iOS or Android, as it doesn't allow to pass a custom nonce to the sign-in request.

For either option, you need to obtain a Web Client ID from the Google Cloud Engine, as explained in the Google Sign In guide.

This guide only uses the @react-oauth/google@latest option for the Web, and the signInWithOAuth for the mobile platforms.

Before proceeding, add a new environment variable to the .env file:

EXPO_PUBLIC_GOOGLE_AUTH_WEB_CLIENT_ID="YOUR_GOOGLE_AUTH_WEB_CLIENT_ID"

MobileWeb

Create the mobile generic button component GoogleSignInButton:

import { supabase } from '@/lib/supabase'
import { useEffect } from 'react'
import { TouchableOpacity } from 'react-native'

import { expo } from '@/app.json'
import { Text } from '@react-navigation/elements'
import { Image } from 'expo-image'
import * as WebBrowser from 'expo-web-browser'

WebBrowser.maybeCompleteAuthSession()

export default function GoogleSignInButton() {
  function extractParamsFromUrl(url: string) {
    const parsedUrl = new URL(url)
    const hash = parsedUrl.hash.substring(1) // Remove the leading '#'
    const params = new URLSearchParams(hash)

    return {
      access_token: params.get('access_token'),
      expires_in: parseInt(params.get('expires_in') || '0'),
      refresh_token: params.get('refresh_token'),
      token_type: params.get('token_type'),
      provider_token: params.get('provider_token'),
      code: params.get('code'),
    }
  }

  async function onSignInButtonPress() {
    console.debug('onSignInButtonPress - start')
    const res = await supabase.auth.signInWithOAuth({
      provider: 'google',
      options: {
        redirectTo: `${expo.scheme}://google-auth`,
        queryParams: { prompt: 'consent' },
        skipBrowserRedirect: true,
      },
    })

    const googleOAuthUrl = res.data.url

    if (!googleOAuthUrl) {
      console.error('no oauth url found!')
      return
    }

    const result = await WebBrowser.openAuthSessionAsync(
      googleOAuthUrl,
      `${expo.scheme}://google-auth`,
      { showInRecents: true }
    ).catch((err) => {
      console.error('onSignInButtonPress - openAuthSessionAsync - error', { err })
      console.log(err)
    })

    console.debug('onSignInButtonPress - openAuthSessionAsync - result', { result })

    if (result && result.type === 'success') {
      console.debug('onSignInButtonPress - openAuthSessionAsync - success')
      const params = extractParamsFromUrl(result.url)
      console.debug('onSignInButtonPress - openAuthSessionAsync - success', { params })

      if (params.access_token && params.refresh_token) {
        console.debug('onSignInButtonPress - setSession')
        const { data, error } = await supabase.auth.setSession({
          access_token: params.access_token,
          refresh_token: params.refresh_token,
        })
        console.debug('onSignInButtonPress - setSession - success', { data, error })
        return
      } else {
        console.error('onSignInButtonPress - setSession - failed')
        // sign in/up failed
      }
    } else {
      console.error('onSignInButtonPress - openAuthSessionAsync - failed')
    }
  }

  // to warm up the browser
  useEffect(() => {
    WebBrowser.warmUpAsync()

    return () => {
      WebBrowser.coolDownAsync()
    }
  }, [])

  return (
    <TouchableOpacity
      onPress={onSignInButtonPress}
      style={{
        flexDirection: 'row',
        alignItems: 'center',
        backgroundColor: '#ffffff',
        borderWidth: 1,
        borderColor: '#dbdbdb',
        borderRadius: 4,
        paddingVertical: 10,
        paddingHorizontal: 15,
        justifyContent: 'center',
        shadowColor: '#000',
        shadowOffset: { width: 0, height: 1 },
        shadowOpacity: 0.1,
        shadowRadius: 2,
        elevation: 2, // For Android shadow
      }}
      activeOpacity={0.8}
    >
      <Image
        source={{ uri: 'https://developers.google.com/identity/images/g-logo.png' }}
        style={{ width: 24, height: 24, marginRight: 10 }}
      />
      <Text
        style={{
          fontSize: 16,
          color: '#757575',
          fontFamily: 'Roboto-Regular', // Assuming Roboto is available; install via expo-google-fonts or similar if needed
          fontWeight: '500',
        }}
      >
        Sign in with Google
      </Text>
    </TouchableOpacity>
  )
}

Finally, update the iOS and Android projects by running the Expo prebuild command:

npx expo prebuild --clean

Now test the application on both iOS and Android:

npx expo run:ios && npx expo run:android

You should see the sign-in screen with the Google authentication button.

The app's home screen after sign-in in a web browser, an Android emulator, and an iPhone simulator. Each screen shows a Welcome heading, the username and full name, a sign-out button, and Home and Explore tabs.

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