React - React Router - A <Router> may have only one child element - javascript

I'm a newbie at React, please correct me if I'm wrong...I've used the Switch tag to enclose multiple Routes in my MainComponent.js file. However, I still got an error that says "A may have only one child element". I'm trying to navigate from one page to another.
For example, when I click on Menu in the landing page, I would like to get routed to Menu.
Please advise what went wrong. Thanks in advance.
index.js
import React from 'react';
import ReactDOM from 'react-dom';
import './index.css';
import App from './App';
import reportWebVitals from './reportWebVitals';
import 'bootstrap/dist/css/bootstrap.min.css';
import 'font-awesome/css/font-awesome.css';
import 'bootstrap-social/bootstrap-social.css';
ReactDOM.render(
<React.StrictMode>
<App />
</React.StrictMode>,
document.getElementById('root')
);
reportWebVitals();
App.js
import React, { Component } from 'react';
import Main from './components/MainComponent';
import './App.css';
import { BrowserRouter } from 'react-router-dom';
class App extends Component {
// pass dishes to children (MenuComponent.js) as props
/*
constructor(props) {
super(props);
this.state = {
dishes: DISHES
};
}*/
render() {
return (
<BrowserRouter> {/* Make use of React Router */}
<div className="App">
<Main />
</div>
</BrowserRouter>
);
}
}
export default App;
MainComponent.js
// Container Component
import React, { Component } from 'react';
import Menu from './MenuComponent';
import DishDetail from './DishdetailComponent';
import Header from './HeaderComponent';
import Footer from './FooterComponent';
import Home from './HomeComponent';
import { DISHES } from '../shared/dishes'; // .. means to go up one level to src
import { Switch, Route, Redirect } from 'react-router-dom';
class Main extends Component {
// pass dishes to children (MenuComponent.js) as props
constructor(props) {
super(props);
this.state = {
dishes: DISHES,
// selectedDish: null
};
}
/*
onDishSelect(dishId) {
this.setState({selectedDish: dishId});
}
*/
render() {
const HomePage = () => {
return (
<Home />
);
}
return (
<div>
<Header />
<Switch>
<Route path="/home" component={HomePage} />
<Route exact path="/menu" component={() => <Menu dishes={this.state.dishes} />} /> {/* path should exactly match /menu and nothing else after /menu */}
{/* component={() => <Menu dishes={this.state.dishes} />} ----> this will allow to pass props to Menu component */}
<Redirect to="/home" /> {/* if the path doesn't match any above, redirect to /home */}
</Switch>
<Footer />
</div>
);
}
}
export default Main;

Just remove the <div className="App"> from your App.js file.
And use the below code as I have written below. It will 100% work for you.
import { BrowserRouter } from 'react-router-dom';
class App extends Component
{
render() {
return (
<BrowserRouter>
<Main/>
</BrowserRouter>
);
}
}
export default App;

Related

React Router not render

I tried using react router but it doesn't work. I already know that React Router Dom v6 has changed from Switch to Routes but when I run the program it just shows a blank screen. Does anyone know how to fix this? Here is my code:
App.js
'''
import React, {Component} from "react";
import { BrowserRouter as Router } from "react-router-dom";
import { render } from "react-dom";
import HomePage from "./HomePage";
export default class App extends Component{
render() {
return (
<Router>
<div>
<HomePage />
</div>
</Router>
);
}
}
const appDiv = document.getElementById("app");
render(<App />,appDiv);
'''
HomePage.js
'''
import React,{Component} from 'react';
import RoomJoinPage from "./RoomJoinPage";
import CreateRoomPage from "./CreateRoomPage";
import { BrowserRouter as Router ,
Routes ,
Route ,
} from "react-router-dom"
export default class HomePage extends Component{
render () {
return (
<Router>
<Routes>
<Route path='/'>
<p>This is Home Page</p>
</Route>
<Route path='/join' element={<RoomJoinPage />} />
<Route path='/create' element={<CreateRoomPage />} />
</Routes>
</Router>
);
}
}
'''
The error is that "You cannot render a Router inside another Router " occurs when we have 2 Router components in the same React application.
So if u see u are calling in App.js and when u call Homepage from app.js it renders again. Thats why everything becomes blank.
and avoid using p tag inside render function in homepage.js
Try doing this:
**App.js**
import React, {Component} from "react";
import { BrowserRouter as Router } from "react-router-dom";
import { render } from "react-dom";
import HomePage from "./HomePage";
export default class App extends Component{
render() {
return (
<div>
<HomePage />
</div>
);
}
}
const appDiv = document.getElementById("app");
render(<App />,appDiv);
**Homepage.js**
import React,{Component} from 'react';
import RoomJoinPage from "./RoomJoinPage";
import CreateRoomPage from "./CreateRoomPage";
import { BrowserRouter as Router ,
Routes ,
Route ,
} from "react-router-dom"
export default class HomePage extends Component{
render () {
return (
<Router>
<Routes>
<Route path='/'>
</Route>
<Route path='/join' element={<RoomJoinPage />} />
<Route path='/create' element={<CreateRoomPage />} />
</Routes>
</Router>
);
}
}

Routing returns white page in React.js

I'm trying to set up routing but for some reason, it returns a blank page and renders nothing.
I'm using router version 6.3.0
// index.js
import React from 'react';
import ReactDOM from 'react-dom';
import { BrowserRouter } from "react-router-dom";
import './index.css';
import App from './App';
ReactDOM.render(
<React.StrictMode>
<BrowserRouter><App /></BrowserRouter>
</React.StrictMode>,
document.getElementById('root')
);
// --------------------------------------------- //
// App.js
import React, { Component, Fragment } from "react";
import { Route } from "react-router-dom";
import Header from "./components/Landing/Header"
import Landing from "./components/Landing/Landing";
import Footer from "./components/Landing/Footer";
class App extends Component {
render() {
return (
<Fragment>
<Header />
<Route path="/landing">
<Landing />
</Route>
<Footer />
</Fragment>
);
}
}
export default App;
// --------------------------------------------- //
// Landing.js
import Body from './Body'
function Landing(props) {
return (
<Body>
<div className="Landing">
Landing Context
</div>
</Body>
)
}
export default Landing;
So when I visit http://localhost:3000/landing nothing is rendered, and when I try http://localhost:3000 nothing is rendered either.
If I remove the <Route></Route> part in App.js, it renders, but on any URL. What do I miss?
As the OP is using react-router-dom v6
Instead of children, it is expecting element props to render the component.
https://reactrouter.com/docs/en/v6/getting-started/overview#configuring-routes
In app.js wrap your route in router like this
import React, { Component, Fragment } from "react";
import { Router, Route } from "react-router-dom";
import Header from "./components/Landing/Header"
import Landing from "./components/Landing/Landing";
import Footer from "./components/Landing/Footer";
class App extends Component {
render() {
return (
<Fragment>
<Header />
<Router>
<Route path="/landing">
<Landing />
</Route>
</Router>
<Footer />
</Fragment>
);
}
}
export default App;
react-router v6 has some breaking changes, it replaced Switch with Routes component:
/ index.js
import React from 'react';
import ReactDOM from 'react-dom';
import { BrowserRouter } from "react-router-dom";
import './index.css';
import App from './App';
ReactDOM.render(
<React.StrictMode>
<BrowserRouter><App /></BrowserRouter>
</React.StrictMode>,
document.getElementById('root')
);
// --------------------------------------------- //
// App.js
import React, { Component, Fragment } from "react";
import { Routes, Route } from "react-router-dom";
import Header from "./components/Landing/Header"
import Landing from "./components/Landing/Landing";
import Footer from "./components/Landing/Footer";
class App extends Component {
render() {
return (
<Fragment>
<Header />
<Routes>
<Route path="/landing" element={<Landing />}/>
</Routes>
<Footer />
</Fragment>
);
}
}
export default App;
https://reactrouter.com/docs/en/v6/getting-started/overview
If your are using react-router version < 6 then you have to add Switch element imported from react-router-dom above your Route Element -
// App.js
import React, { Component, Fragment } from "react";
import { Route, Switch } from "react-router-dom";
class App extends Component {
render() {
return (
<Fragment>
<Switch>
<Route path="/landing">
<div>On LAnding Page</div>
</Route>
</Switch>
</Fragment>
);
}
}
export default App;
And if you are using react-router > 6 then you have to replace Switch with Routes and place your component you want to render inside element property of Route . The code should be similar to following -
// App.js
import React, { Component, Fragment } from "react";
import { Route, Routes } from "react-router-dom";
class App extends Component {
render() {
return (
<Fragment>
<Routes>
<Route path="/landing"
element={<div>On Landing Page</div>}>
</Route>
</Routes>
</Fragment>
);
}
}
export default App;

Hide current component before rendering component linked to Navlink - React Router

I am building a single page web app based on react routing where I want to Hide current component before rendering the next component that is supposed to render after clicking on Navlink just like <a href="someLink"> in html. However, my current component doesn't disappear and the next component renders on the same page next to the current component.
my code for app.js (Main file where parent class renders)
import React from 'react';
import {Parent} from './Parent';
import { BrowserRouter as Router, Route, NavLink} from 'react-router-dom';
function App() {
return (
<div className="App">
<header className="App-header">
<Router>
<NavLink to="/Edit">Edit</NavLink>
<Route path="/Edit" component={Edit}/>
</Router>
</header>
</div>
);
}
export default App;
Here is my code for parent.js -
import React from 'react';
import {Child} from './Child';
import { BrowserRouter as Router, Route, NavLink} from 'react-router-dom';
class Parent extends React.Component{
constructor(props) {
super(props);
}
render(){
return(
<div>
<p>Parent Render</p>
<Router>
<NavLink to="/Parent/Child">Child</NavLink>
<Route path="/Parent/Child" component={Child}/>
</Router>
)
}
}
export {Parent}
Child.js
import React from 'react';
class Child extends React.Component{
constructor(props) {
super(props);
}
render(){
return(
<div>
Child Render
</div>
)}
}
export{Child}
There is no problem in app.js. The problem is that when child navlink is clicked, parent does not disappear
I think the best way to approach it would be to wrap your App.js component with BrowserRouter inside your index.js file like this.
//index.js
import React from "react";
import ReactDOM from "react-dom";
import App from "./App";
import { BrowserRouter as Router } from "react-router-dom";
ReactDOM.render(
<React.StrictMode>
<Router>
<App />
</Router>
</React.StrictMode>,
document.getElementById("root")
);
And subsequently, you can update your App.js component with all the routes you desire to have by wrapping all the components within the Route component like this.
//App.js
import React from "react";
import { Parent } from "./Parent";
import { BrowserRouter as Router, Route, NavLink } from "react-router-dom";
import Home './Home'
import Edit from './Edit'
import Parent from './Parent'
function App() {
return (
<div className="App">
<Switch>
<Route exact path="/" component={Home} />
<Route path="/Edit" component={Edit} />
<Route path="/parent" component={Parent} />
</Switch>
</div>
);
}
export default App;
Now you don't have to wrap your child components with <Router />, you can create as many <Routes /> in App.js and use <Link /> to navigate to that links.

React Where to place login page for a one page app with a side menu

I have a react web app with a sidemenu. Whenever a user clicks on the link in the sidemenu, they are routed to a page that is rendered at the right side of the sidemenu. My question is, how do I do login for such a usecase seeing as any page I route to renders to the right of the sidemenu. I want the login page to be full screen without the side menu showing. This is what App.js looks like.
import React, { Component } from "react";
import { HashRouter } from "react-router-dom";
import Navigation from "./pages/General/components/Navigation";
import SideMenu from "./pages/General/components/SideMenu";
import "../src/css/App.css";
class App extends Component {
render() {
return (
<div>
<HashRouter>
<div className="main-wrapper">
<SideMenu />
<Navigation />
</div>
</HashRouter>
</div>
);
}
}
export default App;
Here is Navigation.js
import React from "react";
import { Route } from "react-router-dom";
import CalendarPage from "../../Calendar/CalendarPage";
import DoctorsList from "../../Doctors/DoctorsList";
import PatientsList from "../../Patients/PatientsList";
import AdminUsersList from "../../AdminUsers/AdminUsersList";
import SpecialitiesList from "../../Specialities/SpecialitiesList";
const Navigation = () => {
return (
<div className="mainarea">
<Route exact path="/" component={CalendarPage} />
<Route exact path="/scheduler" component={CalendarPage} />
<Route exact path="/doctors" component={DoctorsList} />
<Route exact path="/patients" component={PatientsList} />
<Route exact path="/admin-users" component={AdminUsersList} />
<Route exact path="/specialities" component={SpecialitiesList} />
</div>
);
};
export default Navigation;
The best solution I can figure out in terms of a clean design, is to implement another router in your App.jsx, because you are implementing the routing inside your component, and you need another one for your login page.
Then, your App.jsx could be like this:
import React, { Component } from "react";
import { Redirect, Route, Switch } from "react-router-dom";
import LogIn from "./pages/General/components/Login";
import HomePage from "./pages/General/components/HomePage";
import "../src/css/App.css";
class App extends Component {
render() {
return (
<div>
<Switch>
<Route path={'/login'} component={LogIn} />
<Route path={'/'} component={HomePage} />
<Redirect to="/" />
</Switch>
</div>
);
}
}
export default App;
Then, for your HomePage do the following
import React, { Component } from "react";
import { HashRouter } from "react-router-dom";
import Navigation from "./pages/General/components/Navigation";
import SideMenu from "./pages/General/components/SideMenu";
import "../src/css/App.css";
class HomePage extends Component {
render() {
return (
<div>
<HashRouter>
<div className="main-wrapper">
<SideMenu />
<Navigation />
</div>
</HashRouter>
</div>
);
}
}
export default HomePage;
I hope it helps!
Here is my solution, it not exactly a solution, but it will give you a basic idea on how to implement this.
The idea is to place the Login component in app.js, and conditionally display it if the user is logged in.
You will have to pass a handler function to login component through which you will be able to control app.js state.
When login will be sucessfull, u can show the Navigation and Sidemenu component.
import { Fragment } from "react";
import Login from "path/to/login";
class App extends Component {
state = { isLoggedIn: false };
loginHandler = () => {
this.setState({
isLoggedIn: true
});
};
render() {
return (
<div>
<div className="main-wrapper">
{isLoggedIn ? (
<Fragment>
<SideMenu />
<Navigation />
</Fragment>
) : (
<Login loginHandler={this.loginHandler} />
)}
</div>
</div>
);
}
}
Also you need write a separate router file, which will contain the main app.
This is used to show the app component when navigated to /
import React from 'react';
import { HashRouter, Route } from 'react-router-dom';
import App from './app';
const MainRoute = () => (
<HashRouter>
<Route path="/" component={App} />
</HashRouter>
);
export default MainRoute;

React, Uncaught ReferenceError: ReactDOM is not defined

I am doing this Router tutorial.
My App.jsx file:
import React from 'react';
import ReactDOM from 'react-dom';
import { Router, Route, Link, browserHistory, IndexRoute } from 'react-router'
class App extends React.Component {
render() {
return (
<div>
<ul>
<li>Home</Link>
<li>About</Link>
<li>Contact</Link>
</ul>
{this.props.children}
</div>
)
}
}
export default App;
class Home extends React.Component {
render() {
return (
<div>
<h1>Home...</h1>
</div>
)
}
}
export default Home;
class About extends React.Component {
render() {
return (
<div>
<h1>About...</h1>
</div>
)
}
}
export default About;
class Contact extends React.Component {
render() {
return (
<div>
<h1>Contact...</h1>
</div>
)
}
}
export default Contact;
my Main.js file:
ReactDOM.render((
<Router history = {browserHistory}>
<Route path = "/" component = {App}>
<IndexRoute component = {Home} />
<Route path = "home" component = {Home} />
<Route path = "about" component = {About} />
<Route path = "contact" component = {Contact} />
</Route>
</Router>
), document.getElementById('app'))
This error is written to the console: index.js:
Uncaught ReferenceError: ReactDOM is not defined
I really dont know what to do. Followed every tut so far with no errors. Here I have no Idea what to do.
You need to import ReactDOM in Main.js instead of App.jsx, as Main is where you are using ReactDOM to render.
Also need to import React in all files that use JSX.
Finally, also put react-router imports into Main, too.
The way imports work is, you import things you need, in places they're needed. It's not enough to import them once in one file and use in others.
Change Main.js to look like
import ReactDOM from 'react-dom'
import React from 'react'
import { Router, Route, browserHistory, IndexRoute } from 'react-router'
ReactDOM.render((
<Router history = {browserHistory}>
<Route path = "/" component = {App}>
<IndexRoute component = {Home} />
<Route path = "home" component = {Home} />
<Route path = "about" component = {About} />
<Route path = "contact" component = {Contact} />
</Route>
</Router>
), document.getElementById('app'))
This error also happens if there is a Typo
"import ReactDOM from "react-dom";"
and then call Reactdom.render( <App />, document.getElementById('root')) instead of ReactDOM.render....
1) install "npm install --save react-router-dom" with this command.
2) Know modify your App.jsx like this
import React from 'react';
import { Switch, Route, Link} from 'react-router-dom';
class App extends React.Component {
render() {
return (
<div>
<Header/>
<Content/>
</div>
);
}
}
class Header extends React.Component {
render() {
return (
<header>
<nav>
<ul>
<li><Link to='/'>Home</Link></li>
<li><Link to='/about'>About</Link></li>
<li><Link to='/contact'>Contact</Link></li>
</ul>
</nav>
</header>
);
}
}
class Content extends React.Component {
render() {
return (
<main>
<Switch>
<Route exact path='/' component={Home}/>
<Route path='/about' component={About}/>
<Route path='/contact' component={Contact}/>
</Switch>
</main>
);
}
}
class Home extends React.Component {
render() {
return (
<div>
<h1>Home...</h1>
</div>
);
}
}
class About extends React.Component {
render() {
return (
<div>
<h1>About...</h1>
</div>
);
}
}
class Contact extends React.Component {
render() {
return (
<div>
<h1>Contact...</h1>
</div>
);
}
}
export default App;
4) modify your main.js like this
import React from 'react';
import ReactDOM from 'react-dom';
import App from './App.jsx';
import {HashRouter} from 'react-router-dom';
ReactDOM.render((
<HashRouter>
<App />
</HashRouter>
), document.getElementById('app'))
I had the same issue with my ReactDOM.render not to work until I imported the following:
import ReactDOM from 'react-dom'
into the page I created, which was the shopping cart page.
you should import ReactDOM and other stuff in Main.js
import React from 'react';
import ReactDOM from 'react-dom';
import { Router, Route, browserHistory, IndexRoute } from 'react-router'
import {App, Home, About,Contact} from './App'
ReactDOM.render((
<Router history = {browserHistory}>
<Route path = "/" component = {App}>
<IndexRoute component = {Home} />
<Route path = "home" component = {Home} />
<Route path = "about" component = {About} />
<Route path = "contact" component = {Contact} />
</Route>
</Router>
), document.getElementById('app'))
if App.js file contains all components you should change export statements:
from export default Component
to export Component.
And use named import in Main.js import {App, Home, About,Contact} from './App'
import React from 'react';
import { Link, browserHistory} from 'react-router'
class App extends React.Component {
render() {
return (
<div>
<ul>
<li>Home</Link>
<li>About</Link>
<li>Contact</Link>
</ul>
{this.props.children}
</div>
)
}
}
export App;
class Home extends React.Component {
render() {
return (
<div>
<h1>Home...</h1>
</div>
)
}
}
export Home;
class About extends React.Component {
render() {
return (
<div>
<h1>About...</h1>
</div>
)
}
}
export About;
class Contact extends React.Component {
render() {
return (
<div>
<h1>Contact...</h1>
</div>
)
}
}
export Contact;
for browserHistory, you must configure your server appropriately to serve at all routed paths. The simplier way is using hashHistory.
//import hashHistory
import { Router, Route, hashHistory, IndexRoute } from 'react-router'
...
//pass in Router
<Router history = {hashHistory}> ....
I just have a simple solution for it!
in my case the problem was with ReactDom namespace. just change it to something else and it work!
import XReactDom from 'react-dom'
In this tutor this command "npm install react-router" does not save it in package.json file so modify and run command to "npm install --save react-router".
RouterDOM is used in main file, in your case its Main.js (where rendering takes place). Your Main.js file is the starting point and as its render reactDOM but cannot find the import for it.
Just to import it in same file where its used.
I had a similar issue and was able to fix it by importing ReactDOM like this:
import * as ReactDOM from 'react-dom';
And then used it like this:
<Fragment>
{ReactDOM.createPortal(
<Backdrop onConfirm={props.onConfirm} />,
document.getElementById("backdrop-root")
)}
</Fragment>

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