Neha Sharma

Posted on Sep 27, 2024 • Edited on Apr 21 • Originally published at nehasharma.dev

Mastering createPortal in ReactJS: How to create portals in ReactJS

#react #reactjsdevelopment #programming #javascript

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

To watch my previous videos, please check here:

Error boundary
useLayoutEffect
use state
useEffect

To read blogs:

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

Tooltips
Modals
Rendering different parts of DOM
React components render to non-react components
React components render to server-side content

Syntax

import { createPortal } from 'react-dom';
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

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 
  );