如何解决登录后 Firebase 将文档存储到变量？

我正在尝试为我的网站做后端，我已经登录、注册、重置密码等一切正常。我现在想要做的是当用户登录或注册时，AuthContext 检查与他的 UID 匹配的文件，如果存在，则将其存储到变量，或者如果不存在，则创建它并将其存储到变量。只是不能让它工作。到目前为止，我得到的最好的是底部的代码，但问题是当我注销用户时，我收到各种错误，因为用户不再存在。

到目前为止，我的上下文文件看起来像这样，一切正常：

import { createContext,useContext,useEffect,useState } from "react";
import { auth,db } from "../firebase";

export const AuthContext = createContext();

export const useAuth = () => {
  return useContext(AuthContext);
};

const AuthContextProvider = ({ children }) => {
  const [currentUser,setCurrentUser] = useState(null);
  const [currentUserDoc,setCurrentUserDoc] = useState(null);

  const [loading,setLoading] = useState(true);

  const signup = (email,password) => {
    return auth.createuserWithEmailAndPassword(email,password);
  };

  const login = (email,password) => {
    return auth.signInWithEmailAndPassword(email,password);
  };

  const logout = () => {
    return auth.signOut();
  };

  const resetPassword = (email) => {
    return auth.sendPasswordResetEmail(email);
  };

  useEffect(() => {
    const unsubscribe = auth.onAuthStateChanged((user) => {
      setCurrentUser(user);
      setLoading(false);
    });

    return unsubscribe;
  },[]);

  const value = { currentUser,currentUserDoc,signup,login,logout,resetPassword };

  return <AuthContext.Provider value={value}>{!loading && children}</AuthContext.Provider>;
};

export default AuthContextProvider;

我尝试将 useEffect 挂钩更改为此，但无法正确完成：

 useEffect(() => {
    const unsubscribe = auth.onAuthStateChanged(async (user) => {
      setCurrentUser(user);

      const userDoc = db.collection("users").doc(user.uid);
      
      await userDoc.get().then((doc) => {
        if (doc.exists) {
          setCurrentUserDoc(doc.data());
        } else {
          doc.set({
            email: user.email,first_name: "",last_name: "",country: "",organization: "",});
        }
      });

      setLoading(false);
    });

    return unsubscribe;
  },[]);

当没有用户登录时，这是错误的：

我尝试使用它的代码：

import styles from "./Header.module.scss";

import { useAuth } from "../../contexts/AuthContext";

const Header = () => {
  const { logout,currentUserDoc } = useAuth();

  return (
    <header className={styles.header}>
      <div></div>
      <div className={styles.header__user}>
        {currentUserDoc.email}
        <button onClick={logout}>Log out</button>
      </div>
    </header>
  );
};

export default Header;

解决方法

const unsubscribe = auth.onAuthStateChanged(async (user) => {
  // Check if user is present (logged in) or absent (logged out)
  if (!user) {
    // user has logged out
    console.log("No User")
  } else {
    // Add the required documents
    setCurrentUser(user);

    const userDoc = db.collection("users").doc(user.uid);
    const doc = await userDoc.get()
    if (doc.exists) {
      setCurrentUserDoc(doc.data());
    } else {
      await userDoc.set({
        email: user.email,first_name: "",last_name: "",country: "",organization: "",});
    }
  }
})

firebaseAuth.getCurrentUser().updatePhoneNumber(credential).addOnCompleteListener(this,new OnCompleteListener<Void>() {
        @Override
        public void onComplete(@NonNull Task<Void> task) {
            if (task.isSuccessful()) {
                Log.d(TAG,"signInWithCredential:success");

                Snackbar.make(findViewById(android.R.id.content),"Mobile Verified Successfully.",Snackbar.LENGTH_SHORT).show();

            } else {
                Log.w(TAG,"signInWithCredential:failure",task.getException());
                if (task.getException() instanceof FirebaseAuthInvalidCredentialsException) {
                    //mVerificationField.setError("Invalid code.");
                    Snackbar.make(findViewById(android.R.id.content),"Invalid Code.",Snackbar.LENGTH_SHORT).show();
                } else {
                    Toast.makeText(context,"signInWithCredential:failure"+task.getException(),Snackbar.LENGTH_LONG).show();
                }
            }
        }
    });

PhoneAuthCredential credential = PhoneAuthProvider.getCredential(verificationId,code);

// [START auth_state_listener]
    mAuthListener = new FirebaseAuth.AuthStateListener() {
        @Override
        public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
            FirebaseUser user = firebaseAuth.getCurrentUser();
            if (user != null) {
                // User is signed in
                Log.d(TAG, "onAuthStateChanged:signed_in:" + user.getEmail());
            } else {
                // User is signed out
                Log.d(TAG, "onAuthStateChanged:signed_out");
            }
            // [START_EXCLUDE]
            updateUI(user);
            // [END_EXCLUDE]
        }
    };
    // [END auth_state_listener]