Change a prop on a styled component and update appearance - reactjs

Question

I'm very new to styled components (and I'm not great with React in general) and I can't quite get my head around them. I've created a basic example which is an abstraction of what I want to achieve. When I click on the box, I want the property on to be changed to true and for the colour of <Box> to be updated to green as per the background-color rule.
How do I achieve this? Especially in the instance where there could be an indeterminate number of boxes?
Component
import React from 'react';
import PropTypes from 'prop-types';
import styled from 'styled-components';
const Box = styled.a`
display: block;
height: 100px;
width: 100px;
background-color: ${props => props.on ? 'green' : 'red' };
`;
Box.propTypes = {
on: PropTypes.bool,
onClick: PropTypes.func,
}
Box.defaultProps = {
on: false,
onClick: () => {},
}
export default Box;
Implementation
<Box on={ false } onClick={ }></Box>

Answer 1

// App.js
import React from "react";
import ReactDOM from "react-dom";
import Test from "./Test";
class App extends React.Component {
state = {
on: false
};
handleChange = () => {
this.setState(prevState => ({ on: !prevState.on }));
};
render() {
return (
<div className="App">
<Test on={this.state.on} onClick={this.handleChange}>
Hey
</Test>
</div>
);
}
}
const rootElement = document.getElementById("root");
ReactDOM.render(<App />, rootElement);
// Test.js
import PropTypes from "prop-types";
import styled from "styled-components";
const Box = styled.a`
display: block;
height: 100px;
width: 100px;
background-color: ${props => (props.on ? "green" : "red")};
`;
Box.propTypes = {
on: PropTypes.bool,
onClick: PropTypes.func
};
Box.defaultProps = {
on: false,
onClick: () => {}
};
export default Box;

Answer 2

You would handle the state in its parent component. For example you could do something like this:
class Page extends Component {
state = { on: false }
handleClick = () => {
this.setState(prevState => ({ on: !prevState.on }));
}
render() {
return <Box on={this.state.on} onClick={this.handleClick} />
}
}
Or even simpler using React hooks:
const Page = () => {
const [on, setOn] = useState(false);
return <Box on={on} onClick={() => setOn(on => !on)} />;
};
Here's an example of what you could do if you wanted 10 boxes
(note: creating the onClick handler in the render method like I did could cause performance issues if you have a very large number of boxes)
class Page extends Component {
state = { boxes: Array(10).fill(false) }
handleClick = (index) => {
this.setState(prevState => ({
boxes: [
...prevState.boxes.slice(0, index),
!prevState.boxes[index],
...prevState.boxes.slice(index)
]
}));
}
render() {
return (
<React.Fragment>
{this.state.boxes.map((on, index) =>
<Box on={on} onClick={() => this.handleClick(index)} />
)}
</React.Fragment>
);
}
}