将 Apple Sign In 与 React Native Firebase 和 Firestore 一起使用时，如何检查用户是不是存在？

Posted 2023-03-14

【中文标题】将 Apple Sign In 与 React Native Firebase 和 Firestore 一起使用时，如何检查用户是不是存在？

【英文标题】：How can I check if User exists when using Apple Sign In with React Native Firebase and Firestore?将 Apple Sign In 与 React Native Firebase 和 Firestore 一起使用时，如何检查用户是否存在？

【发布时间】：2021-11-13 16:25:05

【问题描述】：

我已经使用 Firebase 在我的 React Native App 中实现了 Apple 登录，并且登录过程运行良好。

我正在将用户详细信息添加到 Firestore 中名为“用户”的数据库集合中。

当用户重新登录时，从他们的个人资料添加到集合中的数据会被覆盖。

如何检查用户是否存在以便仅创建一次集合文档？

我的代码如下

appleSignIn: async () => 
  try 
    const appleAuthRequestResponse = await appleAuth.performRequest(
      requestedOperation: appleAuth.Operation.LOGIN,
      requestedScopes: [appleAuth.Scope.EMAIL, appleAuth.Scope.FULL_NAME],
    );

    if(!appleAuthRequestResponse.identityToken) 
      throw 'Apple Sign-In failed - no identify token returned';
    
    const  identityToken, nonce  = appleAuthRequestResponse;
    const appleCredential = auth.AppleAuthProvider.credential(identityToken, nonce);
    await auth().signInWithCredential(appleCredential);

    firestore().collection('users').doc(auth().currentUser.uid)
               .set(
                 fname: appleAuthRequestResponse.fullName.givenName,
                 lname: appleAuthRequestResponse.fullName.familyName,
                 email: appleAuthRequestResponse.email,
                 createdAt: firestore.Timestamp.fromDate(new Date()),
                 userImg: null,
               )

   catch (e) 
    console.log(e);
  
,

【参考方案1】：

您可以检查users集合中是否存在用户。

...
await auth().signInWithCredential(appleCredential);
const existingUserDoc = await firestore().collection('users').doc(auth().currentUser.uid).get();

if (existingUserDoc && existingUserDoc.exists) 
 // you can do something here. user details already created.
 else 
firestore().collection('users').doc(auth().currentUser.uid)
    .set(
        fname: appleAuthRequestResponse.fullName.givenName,
        lname: appleAuthRequestResponse.fullName.familyName,
        email: appleAuthRequestResponse.email,
        createdAt: firestore.Timestamp.fromDate(new Date()),
        userImg: null,
    );

...

或者更简单的方法，如果用户文档存在，您可以通过firestore().collection('users').doc('uid').set(...) 执行。

...
await auth().signInWithCredential(appleCredential);
const existingUserDoc = await firestore().collection('users').doc(auth().currentUser.uid).get();

// ignore execution of setting user deatils.
if (!existingUserDoc && !existingUserDoc.exists) 
    firestore().collection('users').doc(auth().currentUser.uid)
        .set(
            fname: appleAuthRequestResponse.fullName.givenName,
            lname: appleAuthRequestResponse.fullName.familyName,
            email: appleAuthRequestResponse.email,
            createdAt: firestore.Timestamp.fromDate(new Date()),
            userImg: null,
        );

...