如何解决“函数作为 React 子级无效”。 当我尝试根据函数的输出渲染组件时出错？

Question

In my App.js file of the application, I am setting the routes of the app.

This is the code of my App.js file

import React, {useEffect} from "react";
import {Container} from '@material-ui/core';
import {BrowserRouter, Routes, Route, Navigate} from 'react-router-dom';
import { gapi } from 'gapi-script';
import Navbar from "./components/Navbar/Navbar";
import Home from './components/Home/Home';
import Auth from "./components/Auth/Auth";
import MealsPage from "./components/MealsPage/MealsPage";
import WorkoutDetails from "./components/WorkoutDetails/WorkoutDetails";

const App=()=>{
  const user=JSON.parse(localStorage.getItem('profile'));

    useEffect(() => {
        const start = () => {
          gapi.auth2.init({
            clientId: process.env.REACT_APP_GOOGLE_API_TOKEN,
            scope: ""
          })
        };
    
        gapi.load('client:auth2', start);
      })

     
    return(
        <BrowserRouter>
        <Container maxWidth="xl">
        <Navbar/>
        <Routes>
            <Route path="/" exact ={()=>{<Navigate to="/workouts"/>}}/>
            <Route path="/workouts" exact element={<Home/>}/>
            <Route path="/workouts/search" exact element={<Home/>}/>
            <Route path="/workouts/:id" element={<WorkoutDetails/>}/>
            <Route path="/meals" exact element={<MealsPage/>}/>
        <Route path="/auth" exact element={()=>{!user? <Auth/>:<Navigate to="/workouts"/>}}/>
        </Routes>
  
        </Container>
        </BrowserRouter>
    );
}

export default App;

I am getting an error that says this:

react-dom.development.js:67 
        
       Warning: Functions are not valid as a React child. This may happen if you return a Component instead of <Component /> from render. Or maybe you meant to call this function rather than return it.

I assume it is from the Auth route as it does not specify an element to render when we have that specific route, but it specifies a function. Basically, when the user is logged in, he should not see the auth component because he is already logged in and he should be redirected to the '/workouts' route which is another page in the application.

Could you help me solve this?

Answer 1

Here element={()=>{!user? <Auth/>:<Navigate to="/workouts"/>}} element={()=>{!user? <Auth/>:<Navigate to="/workouts"/>}} . Try it like element={user? <Navigate to="/workouts"/> : <Auth/>} element={user? <Navigate to="/workouts"/> : <Auth/>} or return component like element={()=>!user? <Auth/>:<Navigate to="/workouts"/>} element={()=>!user? <Auth/>:<Navigate to="/workouts"/>} or element={()=>{return !user? <Auth/>:<Navigate to="/workouts"/>}} element={()=>{return !user? <Auth/>:<Navigate to="/workouts"/>}}

Answer 2

Looking at the documentation for <Route /> , the element prop is meant to be an element - not a function returning an element .

Therefore, you should simply be able to remove the function call and pass the element directly:

<Route
  path="/auth"
  exact
  element={!user ? <Auth/> : <Navigate to="/workouts"/>}
/>