受保护路由、上下文 API 和 firebase 用户身份验证请求的问题

Question

我正在编写一个使用 Firebase 进行身份验证的基本 CRUD React 应用程序。目前我正在尝试为名为 Dashboard 的组件创建一个受保护的路由。受保护的路由确保任何封装的路由（例如仪表板）不会呈现，除非用户 authenticated.If 用户未通过身份验证然后路由器重定向到登录页面。

我完成此操作的方式是仿照 this 文章：

我模拟了上面文章中的模式，效果很好。当我合并 firebase（特别是 firebase 身份验证）时，即使用户已登录，我的应用程序也不会呈现 Dashboard 组件。相反，它只是重定向到着陆页

我知道问题出在哪里（我认为），但我不确定如何解决它。

问题是对 firebase 的调用是一个异步操作，仪表板会在对 firebase 的调用被解析之前尝试加载。

我想知道他们是否可以对我的代码进行任何调整以解决此问题。

我可以 api 调用 firebase 每次用户加载受保护的路由（以检查身份验证），但我更愿意将身份验证设置为上下文的状态并引用该状态，直到用户登录或注销。

我已将相关代码放在下面。所有文件都在 src 目录

谢谢！

App.js

import React, { Component } from 'react';
import { BrowserRouter, Route, Redirect } from "react-router-dom";
import {Switch} from 'react-router';
import Landing from './PageComponents/Landing';
import {Provider} from './PageComponents/Context';
import Dashboard from './PageComponents/Dashboard';
import ProtectedRoute from './PageComponents/ProtectedRoute';

class App extends Component {
  render() {
    return (
      <div className="App">

      <Provider>
        <BrowserRouter>

        <div>
          <Switch>

            <Route exact={true} path="/" component={Landing} />
            <ProtectedRoute exact path="/dashboard" component={Dashboard} /> 

          </Switch>
        </div>

        </BrowserRouter>
        </Provider>

      </div>
    );
  }
}

export default App;

PageComponents/Context.js

import React from 'react';
import { getUser } from '../services/authentication';

let Context = React.createContext();

class Provider extends React.Component {

    state = {
        userID: true,
        user:undefined,
        authenticated:false
    }

    async getUser(){

        try{

            let user = await getUser();

            return user

        } catch(error){

            console.log(error.message)
        }

    }


    async componentDidMount(){

        console.log("waiting to get user")
        let user = await this.getUser();
        console.log(user)
        console.log("got user")

        this.setState({
          userID: user.uid,
          user:user,
          authenticated:true
        })
    }


    render(){
        console.log(this.state)
        return(
            <Context.Provider value={{   
                 state:this.state
            }}>
                {this.props.children}
            </Context.Provider>
        )
    }
}

const Consumer = Context.Consumer;

export {Provider, Consumer};

PageComponents/Dashboard

import * as React from 'react';
import {Consumer} from '../../PageComponents/Context';



class Dashboard extends React.Component {
  render(){

    console.log("Dashboard component loading....")

     return(


        <Consumer>
            {(state)=>{
                console.log(state)
                return(
                  <div>
                    <p> Dashboard render</p>
                  </div>
                )
             }}
        </Consumer>
     )
  }
}

export default Dashboard

PageComponents/ProtectedRoute


import React from 'react';
import { Route, Redirect } from 'react-router-dom';
import { Consumer } from '../PageComponents/Context';


const ProtectedRoute = ({ component: Component, ...rest }) => {
    console.log("Middleware worked!");

    return (

        <Consumer>
               {(context)=>{
                /*________________________BEGIN making sure middleware works and state is referenced */
                  console.log(context);
                  console.log("Middle ware");
                /*________________________END making sure middleware works and state is referenced */

                 console.log(  context.getState().authenticated + " <--- is authenticated from ProtectedRoute. true or false?")

                  if(context.state.authenticated){

                    return(

                        <Route {...rest} render={renderProps => {
                           console.log(renderProps);
                           return (<Component {...renderProps} />)
                        }}/>

                    )  

                  }else{

                    return <Redirect to="/"/>

                  }

                }}

        </Consumer>
    )


};

export default ProtectedRoute;

services/authentication

import firebase from '../../services/firebase'




const getUser = () =>{

    return new Promise((resolve, reject) => {   // Step 3. Return a promise

         //___________________ wrapped async function

         firebase.auth().onAuthStateChanged((user)=> {

                if(user){

                    resolve(user);   //____This is the returned value of a promise

                 }else{

                   reject(new Error("Get user error"))

                }
         })

       //_____________________END wrapped async function  

    });

}


export {getUser }

Answer 1

问题：你确实是对的，API对getUser的调用是异步的并且在componentDidMount中触发，因此由authentication 状态设置为 true 时，Redirect 组件已被触发。

解决方案： 需要等到认证请求成功，然后决定加载路由或在ProtectedRoute组件中重定向。

为了让它工作，你需要一个加载状态。

PageComponents/Context.js

let Context = React.createContext();

class Provider extends React.Component {

    state = {
        userID: true,
        user:undefined,
        loading: true,
        authenticated:false
    }

    async getUser(){
       let user = await getUser();
       return user

    }


    async componentDidMount(){
        console.log("waiting to get user")
        try {
          let user = await this.getUser();
          console.log(user)
          console.log("got user")

          this.setState({
            userID: user.uid,
            user:user,
            loading: false,
            authenticated:true
          })
       } catch(error) {
           console.log(error);
           this.setState({
               loading: false,
               authenticated: false
           })
       }
    }


    render(){
        return(

            <Context.Provider value={{
                 state:this.state
            }}>
              {this.props.children}
            </Context.Provider>

        )
    }
}


const Consumer = Context.Consumer;

export {Provider, Consumer}

PageComponents/ProtectedRoute

import React from 'react';
import { Route, Redirect } from 'react-router-dom';
import { Consumer } from '../PageComponents/Context';


const ProtectedRoute = ({ component: Component, ...rest }) => {
    console.log("Middleware worked!");
    return (
        <Consumer>
            {(context)=>{
                /* BEGIN making sure middleware works and state is referenced */
                  console.log(context);
                  console.log("Middle ware");
                /* END making sure middleware works and state is referenced */

                 console.log(  context.getState().authenticated + " <--- is authenticated from ProtectedRoute. true or false?")

                 // Show loading state 
                 if (context.state.loading) {
                     return <Loader /> 
                 }
                 if(context.state.authenticated){
                    return(
                        <Route {...rest} render={renderProps => {
                           console.log(renderProps);
                           return (<Component {...renderProps} />)
                        }}/>
                    )  
                  }else{
                    return <Redirect to="/"/>
                  }
                }}
        </Consumer>
    )
};

export default ProtectedRoute;

受保护路由、上下文 API 和 firebase 用户身份验证请求的问题

Problem with protected routes, context API and firebase user authentication request

javascript

firebase

reactjs

firebase-authentication

react-context