Firebase 身份验证在页面刷新时消失

Question

我有一个使用 firebase 身份验证的简单 React 应用程序。成功登录后，firebase:authUser 存储在 localStorage 中。但是在每次页面刷新时，localStorage 都会被清除并且会话会丢失。浏览其他页面并不会清除 localStorage。

代码如下所示：

Index.js

import React from 'react';
import ReactDOM from 'react-dom';
import './index.css';
import App from './App';
import reportWebVitals from './reportWebVitals';

ReactDOM.render(
  <React.StrictMode>
    <App />
  </React.StrictMode>,
  document.getElementById('root')
);

reportWebVitals();

App.js

import { BrowserRouter as Router, Route, Routes } from "react-router-dom";
import Login from './Login';
import Main from './Main';
import Info from './Info';
import './App.css';

function App() {
  return (
    <div className="App">
        <Router>
          <Routes>
            <Route path="/login" element={<Login/>} />
            <Route path="/" element={<Main/>} />
            <Route path="/info" element={<Info/>} />
          </Routes>
        </Router>
    </div>
  );
}

export default App;

Info.js → 无需身份验证即可查看的随机页面。在此页面 (http://localhost:3000/info) 上刷新也会清除 localStorage

import { useNavigate } from "react-router-dom";

function Info() {

    const navigate = useNavigate();
        return (
            <div>
                <div>
                    Info page
                </div>
                <button
                    onClick={() => {
                            navigate('/');
                        }
                    }>
                        Go to Main
                </button>
            </div>
        );
}

export default Info;

这是firebase.js我用来验证用户

import { initializeApp } from 'firebase/app';
import { getAuth, createUserWithEmailAndPassword, signInWithEmailAndPassword, signOut, setPersistence, browserLocalPersistence } from 'firebase/auth';

const firebaseConfig = {
  // Here is my config
};

initializeApp(firebaseConfig);

// Auth
const auth = getAuth();
var email;
var password;

// Auth - set persistance
setPersistence(auth, browserLocalPersistence);

// Auth - create
createUserWithEmailAndPassword(auth, email, password)
  .then((userCredential) => {
    // Signed in 
    const user = userCredential.user;
  })
  .catch((error) => {
    const errorCode = error.code;
    const errorMessage = error.message;
  });

// Auth - Login
signInWithEmailAndPassword(auth, email, password)
  .then((userCredential) => {
    // Signed in 
    const user = userCredential.user;
  })
  .catch((error) => {
    const errorCode = error.code;
    const errorMessage = error.message;
  });

// Auth - signOut
signOut(auth).then(() => {
  // Sign-out successful.
}).catch((error) => {
  // An error happened.
});

export {
  auth,
  db,
  createUserWithEmailAndPassword,
  signInWithEmailAndPassword,
  signOut
};

Answer 1

在大多数浏览器中，当您重新加载页面时，默认情况下 Firebase 已经从本地存储恢复用户身份验证状态。但是由于这需要它调用服务器，它可能需要一些时间才能初始化当前用户，您应该使用所谓的身份验证状态侦听器，如 getting the current user 文档中的第一个代码示例所示：

import { getAuth, onAuthStateChanged } from "firebase/auth";

const auth = getAuth();
onAuthStateChanged(auth, (user) => {
  if (user) {
    // User is signed in, see docs for a list of available properties
    // https://firebase.google.com/docs/reference/js/firebase.User
    const uid = user.uid;
    // ...
  } else {
    // User is signed out
    // ...
  }
});

您的代码似乎只处理用户明确登录的情况，因此它永远不会获取恢复的用户。

如果上述方法有效，请检查您是否确实需要调用 setPersistence(auth, browserLocalPersistence);。如前所述，在浏览器上这应该已经是默认行为了。

Firebase 身份验证在页面刷新时消失

Firebase authentication disappears on page refresh

javascript

local-storage

firebase

reactjs

firebase-authentication