Display element based on event fired and props passed in - reactjs

Question

I am trying, to manipulate another element, by, passing props directly to it, and then have it display itself. If I pass true/false.
Live running code:
https://codesandbox.io/s/keen-dan-rt0kj
I don't know if it's possible to have a system of objects, and based on an event, tell a parent to display a child.
App.js
import React from "react";
import "./styles.css";
import Content from "./components/Content";
export default class App extends React.Component {
state = {
display: false
};
render() {
return (
<div className="App">
<button onClick={() => this.setState({ display: !this.state.display })}>
Display div
</button>
<Content display={this.state.display} />
</div>
);
}
}
./components/Content.js:
import React from "react";
export default class Content extends React.Component {
constructor(props) {
super();
this.state = {
display: props.display
};
}
render() {
const { display } = this.state;
return (
<div
id="mydiv"
className="mydiv"
style={{ display: display ? "block" : "none" }}
>
<h3>A simple div</h3>
</div>
);
}
}
Goal:
I want to based on a state, and based on fired event, display an element that already in store of root.
EDIT: I am aware that, this exists and can be used: import PropTypes from 'prop-types', however, I am not sure this is good practice, since it requires some parent or some other component to implement the props.
JUST Tried:
App:
<Content display={this.state.display} content={"Hello World"} />
Content:
<h3>{this.state.content}</h3>
It seems the passed in text, stored in Content state = {content: props.content} does get displayed, wheres, the boolean value does not work directly. Is there something wrong with sending in a bool ?

Answer 1

try this in your Content Component
export default class Content extends React.Component {
constructor(props) {
super();
this.state = {
};
}
render() {
return (
<>
{this.props.display?(
<div
id="mydiv"
className="mydiv"
>
<h3>A simple div</h3>
</div>
):null}
</>
);
}
}

Answer 2

The reason this may not be working is because you are initiating the state in a way that does not connect the display props after the component is initialized. This means that after the Content component is "constructed", the state of the Content and it's parent are not linked. This is because the constructor() function is only run once to initialize the state.
The best option you have is to not use the internal state of the Content component. Rather than initializing state with the display prop, just use the display prop in your render function.
Trying something like this might work
import React from "react";
export default class Content extends React.Component {
constructor(props) {
super(props);
}
render() {
const { display } = this.props;
return (
<div
id="mydiv"
className="mydiv"
style={{ display: display ? "block" : "none" }}
>
<h3>A simple div</h3>
</div>
);
}
}
Also I would reccommend using state in the root:
import React from "react";
import "./styles.css";
import Content from "./components/Content";
export default class App extends React.Component {
constructor(props) {
super();
state = {
display: false
};
}
render() {
return (
<div className="App">
<button onClick={() => this.setState({ display: !this.state.display })}>
Display div
</button>
<Content display={this.state.display} />
</div>
);
}
}