Problem with showing a component which is in another file onclick - reactjs

Question

I am currently building an website in React with a navigation bar which I use Material-UI for.
My problem is that when I for example click "About" in my navigation bar, I want to show the content/component in About, and when I click Home I want the component Home to be shown and others hidden.
The problem is I am still a beginner in React and want to practice my React skills and now I have the navbar, Home, About in seperate files and not sure on how to pass through state, props and so in this case.
I will show a screen shot on the website and code-snippets to show my code so far.
My website:
File structure of my program:
Here is Code:
App.js:
import React, { Component } from 'react';
import logo from './logo.svg';
import './App.css';
import NavBar from './Components/Navigationbar'
import Home from './Components/Home'
import About from './Components/About'
class App extends Component {
constructor(props){
super(props);
this.state = {showAbout: true};
this.handleAbout = this.handleAbout.bind(this);
}
handleAbout(){
this.setState({showAbout: true})
}
render() {
return (
<div className="App">
<div className="App-header">
</div>
<NavBar></NavBar>
<p className="App-intro">
<Home></Home>
</p>
{this.state.showAbout ? <About /> : null}
</div>
);
}
}
export default App;
Home.jsx:
import React from 'react';
import { makeStyles } from '#material-ui/core/styles';
import Paper from '#material-ui/core/Paper';
import Typography from '#material-ui/core/Typography';
const useStyles = makeStyles(theme => ({
root: {
padding: theme.spacing(3, 2),
backgroundColor: 'mistyrose'
},
}));
export default function PaperSheet() {
const classes = useStyles();
return (
<div>
<Paper className={classes.root}>
<Typography variant="h5" component="h3">
Home
</Typography>
<Typography component="p">
Welcome Home
</Typography>
</Paper>
</div>
);
}
About.jsx:
import React from 'react';
import { makeStyles } from '#material-ui/core/styles';
import Paper from '#material-ui/core/Paper';
import Typography from '#material-ui/core/Typography';
const useStyles = makeStyles(theme => ({
root: {
padding: theme.spacing(3, 2),
backgroundColor: 'mistyrose'
},
}));
export default function PaperSheet() {
const classes = useStyles();
return (
<div>
<Paper className={classes.root}>
<Typography variant="h5" component="h3">
About
</Typography>
<Typography component="p">
About
</Typography>
</Paper>
</div>
);
}
And finally the navigation bar which is from Material UI:
Navigationbar.jsx:
import React from 'react';
import ReactDOM from 'react-dom';
import Button from '#material-ui/core/Button';
import App from '../App';
import { makeStyles } from '#material-ui/core/styles';
import Paper from '#material-ui/core/Paper';
import Tabs from '#material-ui/core/Tabs';
import Tab from '#material-ui/core/Tab';
import About from './About';
const useStyles = makeStyles({
root: {
flexGrow: 1,
},
});
function handleAbout(props){
alert('About');
}
const navBar = (props) => {
return (
<Paper >
<Tabs
//value={value}
onChange={handleChange}
indicatorColor="primary"
textColor="primary"
centered
>
<Tab label="Home" />
<Tab label="About" onClick={() => handleAbout(props)} />
<Tab label="Contact" />
</Tabs>
</Paper>
);
}
//ReactDOM.render(<navBar />, document.querySelector('#app'));
export default navBar;
My problem is I want to when I click "About" in the navbar, I want to show the About component(the content in About.jsx) on my website but not sure on how to handle state and props in the case when they are in seperate files.
Would appreciate if someone could help me.
Thanks a lot.

Answer 1

You can use react-router for navigation. How to install and use it is quite nicely shown on the page: https://reacttraining.com/react-router/web/guides/quick-start

Answer 2

Oh boy, this is a big one...
In the simplest case, you pass state though props like this:
<ChildComponent showAbout={this.state.showAbout}/>, and access it in ChildComponent by props.showAbout (or this.props.showAbout if it's a class component).
But things can get complicated as your application scales. Values can only be passed through props downwards inside the component tree; in other words, a component can only see a state that's somewhere above it. You can't use state from a sibling component or a component below it.
And that's the whole reason state management libraries exist. They provide a 'global' state that is available anywhere in the app. Redux is one of them.
You should sit down and learn Redux, as you can't really make a big app without a state management tool.
Another thing you should learn is react-router, for client-side routing.
Those things combined will provide a powerful tool for making useful apps.