React Nativeアプリを構築し、Firebaseと統合する方法

このチュートリアルでは、Firebaseバックエンドと統合されたReactNativeアプリを構築します。このアプリは、React NativeCLIとExpoCLIの両方をサポートします。

このReactNative Firebaseチュートリアルでは、認証、登録、データベース(Firestore)CRUD操作などの主な機能について説明します。



  1. Firebaseプロジェクトの作成
  2. 新しいReactNativeアプリの作成と構成
  3. フォルダ構造、ルート、およびナビゲーションの設定
  4. ログイン、登録、ホーム画面のUIの実装
  5. FirebaseAuthへの登録
  6. FirebaseAuthでログインする
  7. 永続的なログイン資格情報
  8. FirebaseFirestoreからのデータの書き込みと読み取り

さらに面倒なことはせずに、React NativeFirebaseプロジェクトの構築を始めましょう。最終的なモバイルアプリは次のようになります。




  • Firebase.comで新しいアカウントを作成します
  • FirebaseConsoleで新しいプロジェクトを作成する
  • FirebaseConsoleでEメールとパスワードの認証方法を有効にする->認証->サインイン方法
  • アプリIDcom.reactnativefirebaseを使用して新しいiOSアプリを作成します
  • (オプション)パッケージ名com.reactnativefirebaseで新しいAndroidアプリを作成します
  • 次のステップで生成された構成ファイルをコンピューターにダウンロードします(iOSの場合はGoogleService-Info.plist、Androidの場合はgoogle-services.json



Firebaseでは、ユーザー、データ、ファイル、プッシュ通知トークンなど、アプリに必要なすべてのものを保存できます。これらの情報はすべて、ReactNativeと互換性のあるFirebaseSDKを介してモバイルクライアントで利用できます。 。つまり、バックエンドとのすべてのやり取りが抽象化されてSDKにカプセル化されるため、モバイル開発者はAPI呼び出し、データ解析、ソケット管理などについて心配する必要がありません。


React NativeFirebaseアプリをExpoCLIとReactNativeCLIの両方と互換性のあるものにします。


ExpoとReactNative CLIの両方と互換性があり、Googleによって直接サポートされているFirebase WebSDKを使用します。


  • Googleによって直接サポートされていないため、バグを引き起こす可能性のある追加のレイヤーであるため、保守がはるかに困難になります。
  • また、Expoでも機能しません。これは、多くの開発者にとって取引を妨げる可能性があります。


  • ExpoCLIをインストールする


npm install -g expo-cli
  • を実行して新しいReactNativeアプリを作成します
expo init react-native-firebase 

テンプレートとして、管理ワークフロー — 空白を選択します

  • 実行してアプリを起動します
yarn ios // or yarn android 



  • FirebaseSDKをReactNativeプロジェクトに追加します
yarn add firebase 
  • を実行してReactNativeNavigationライブラリを追加します
yarn add @react-navigation/native && yarn add @react-navigation/stack && expo install react-native-gesture-handler react-native-reanimated react-native-screens react-native-safe-area-context @react-native-community/masked-view
  • プロジェクトで使用するさまざまなUIコンポーネントとパッケージを追加します
yarn add react-native-keyboard-aware-scroll-view base-64 


mkdir src src/firebase && touch src/firebase/config.js

Firebase設定をsrc / firebase /config.jsに追加します

You can get all this information from Firebase Console -> Project Settings

3. Create the Folder Structure and Set Up Routes and Navigation

  • Create the folder structure by running
mkdir src/screens src/screens/LoginScreen src/screens/RegistrationScreen src/screens/HomeScreen
  • Create the files structure by running
touch src/screens/index.js src/screens/LoginScreen/LoginScreen.js src/screens/LoginScreen/styles.js src/screens/RegistrationScreen/RegistrationScreen.js src/screens/styles.js src/screens/HomeScreen/HomeScreen.js src/screens/HomeScreen/styles.js
  • Add this code to src/screens/index.js
export { default as LoginScreen } from './LoginScreen/LoginScreen' export { default as HomeScreen } from './HomeScreen/HomeScreen' export { default as RegistrationScreen } from './RegistrationScreen/RegistrationScreen' 

Don’t worry if the project is broken! Everything will make sense in a little while.

  • Set up the routes & navigators

Override App.js file with the following code snippet:

4. Implement the UI

Now that we have the scaffold of the app, let’s go ahead and implement the UI components of all screens. We’re not going into the details of flex layout and React Native styling, since that is outside the scope for this tutorial. We’re going to focus mostly on React Native Firebase integration.

Simply override the files as follows:

  • src/LoginScreen/LoginScreen.js
  • src/LoginScreen/styles.js
  • src/RegistrationScreen/RegistrationScreen.js
  • src/RegistrationScreen/styles.js
  • src/HomeScreen/HomeScreen.js
  • src/HomeScreen/styles.js

At this point, your app should run properly and display the following screens (UI only):


You can switch between the two screens by tapping the links buttons in the footer.

Now that we have a beautiful UI for login and sign up, let’s see how we can integrate our React Native (and Expo) app with Firebase.

5. React Native Firebase — Registration

Let’s start with creating a new account with Firebase Auth, since naturally login comes after. For this, we are going to add the Firebase logic for creating a new account with email & password in RegistrationScreen.js, by implementing the onRegisterPress method as follows:

In the account creation flow above, we do a few important things:

  • We call Firebase Auth’s createUserWithEmailAndPassword API (line 13), which creates a new account that will show up in Firebase Console -> Authentication table.
  • If the account registration was successful, we also store the user data in Firebase Firestore (line 24). This is necessary for storing extra user information, such as full name, profile photo URL, and so on, which cannot be stored in the Authentication table.
  • If registration was successful, we navigate to the Home Screen, by passing in the user object data as well.
  • If any error occurs, we simply show an alert with it. Errors can be things such as no network connection, password too short, email invalid, and so on.

Reload your app and test the registration. If you successfully created one account, check that it shows up in Firebase Console ->Authentication:

6. React Native Firebase — Login

Now that we are able to create new accounts, let’s implement the login functionality. Firebase SDK takes care of all the authorization and authentication steps needed for a secure login.

Open LoginScreen.js, import firebase and complete the onLoginPress method:

Reload your app and go ahead and login with an existing account. The app should take you to the home screen if the credentials were correct, or it will alert you with an error if anything went wrong.

7. Persist Login Credentials

You’ll notice that if you quit the app and open it again, it will show the login screen again. For a good user experience, we’d want to land all logged in users on the Home screen. No one wants to type in their login credentials every time they want to use an app.

This is also known as persistent login. Fortunately, Firebase SDK takes care of this for us, dealing with all the security concerns. Persistent login is enabled by default in Firebase, so all we need to do is fetch the currently logged in user.

Open App.js and let’s implement the persistent login feature:

onAuthStateChanged returns the currently logged in user. We then fetch all the extra user data that we stored in Firestore, and set it on the current component’s state. This will re-render the app component, which will display the Home screen.

Notice how we call this the first time the app loads by leveraging the useEffect hook.

8. Writing and Reading Data from Firebase Firestore

We’ve already used Firestore above, for saving extra information on our users (the full name). In this dedicated section, we’re going to see how we can write data to Firestore, and how we can query it.

We’ll also cover how to observe (listen to) changes in the Firestore collection and have those be reflected on the screen, in real-time. These can be very helpful in real-time apps, such as a React Native Chat.

To simplify, we are going to save some text items into a Firestore collection named “entities”. Think of these as tasks, posts, tweets, anything you want. We’ll create a simple file that adds a new entity and we’ll also list all the entities that belong to the currently logged in user. Additionally, the list will be updated in real-time.

  • Implement HomeScreen.js by rewriting it to the code below
  • Style the home screen, by overriding HomeScreen/styles.js to:
  • Reload the app and observe the new home screen. Type in some text and press the Add button
  • Nothing happened.
  • Create an index on the entities Firestore collection

You’ll notice that the list of entities is not rendered. If you check out the logs, you’ll see an warning about “The query requires an index”, followed by a long URL:

This informs us that we can’t query the entities table by authorID and sort the data by createdAt in descending order, unless we create an index. Creating an index is actually really easy — simply click on that URL and then click the button:

  • Reload the app again

Now everything works as expected:

  • The app lists all the entities in the entities collection, in descending creation order
  • Adding a new entity works fine
  • The list updates in real-time (try deleting an entry directly in the database, or adding a new one directly from the app)

This is how your Firestore database looks like now:

This is how you read and write from Firestore in React Native. Let’s move forward to the last section.

Play around with the app, by adding new entities. This is the final project:


Firebase makes it really easy to add authentication and database support to any React Native app. Firebase SDK is extremely powerful, supporting a lot of common reading and writing database patterns.

In addition to React Native, Firebase SDK provides support for a lot of other languages, such as Swift, Kotlin or Flutter. Check out those links for similar Firebase starter kits in various languages.

We’ve showcased the most basic ones in this React Native Firebase tutorial. In the next series, we’ll cover more advanced features, such as Firebase Storage (file upload) and push notifications.