Mastering createPortal in ReactJS: How to create portals in ReactJS

Continuing the "Mastering ReactJS Series", in this blog we will learn about createPortal.

To watch my previous videos, please check here:

1. Error boundary

2. useLayoutEffect

3. use state

4. useEffect

To read blogs:

1. Link

What is createPortal

As per the official documentation, createPortal let us render some children into a different part of the DOM.

In simple words,createPortal lets you to render the component outside the current parent, or hierarchy.

In above diagram, because we are using createPortal, 2nd div will be render outside the parent's div.

Use cases

1. Tooltips

2. Modals

3. Rendering different parts of DOM

4. React components render to non-react components

5. React components render to server-side content

Syntax

1. import { createPortal } from 'react-dom';

2. createPortal(children, domNode, key?)

children: the jsx

domNode: where you want the portal to be created

key: an optional, A unique string or number to be used as the portal’s key.

Code

1. render outside current parent hierarchy

import React from "react";
import { createPortal } from "react-dom";

function App() {
  return (
    <div style={{ padding: "100px" }}>
      <h1>React Tooltip with Portal</h1>
      {createPortal(<h1>I am from create portal</h1>, document.getElementById('root') )}
    </div>
  );
}

export default App;

2 . render inside the root

import React from "react";
import { createPortal } from "react-dom";

function App() {
  return (
    <div style={{ padding: "100px" }}>
      <h1>React Tooltip with Portal</h1>
      {createPortal(<h1>I am from create portal</h1>, document.getElementById('root') )}
    </div>
  );
}

export default App;

3 . create a separate component

  return ReactDOM.createPortal(
    <div style={{ ...tooltipStyle, top: position.top, left: position.left }}>
      {text}
    </div>,
    document.body 
  );

Check code examples here

Happy Learning!!