Tutorial

A Guide for Refs in React

Published on August 18, 2019
Default avatar

By William Le

A Guide for Refs in React

While we believe that this content benefits our community, we have not yet thoroughly reviewed it. If you have any suggestions for improvements, please let us know by clicking the “report an issue“ button at the bottom of the tutorial.

Sometimes when using React.js you’ll need an escape hatch to write imperative-style code to interact directly with DOM elements. Using React’s createRef method allows you to do just that!

React provides a way to get references to DOM nodes by using React.createRef(). It’s really just an equivalent of this all-too-familiar snippet of JavaScript:

document.getElementById('foo-id');

This is exactly what React.createRef() does, although it requires a bit of a different setup.

Usage

To get the a reference to the DOM node you have to do two things:

import React, { Component } from 'react';

class Foobar extends Component {
  constructor(props) {
    super(props);
    this.myInput = React.createRef();    // initialize "this.myInput"  
  }

  render() {
    return (
      <input ref={this.myInput}/>        {/* pass "this.myInput" as prop */}
    );
  }
}

All standard HTML elements in React have a reserved prop called ref (much like style which is a reserved prop). Simply pass the ref you initialized in the constructor to the ref prop… and voila! You can start interacting with the <input> DOM node by using this.myInput.current!

this.myInput.current holds the reference to the DOM node


Example: Focusing an <input>

Taking that last code snippet, let’s make a small adjustment to demonstrate how we could start interacting with the <input> DOM node:

import React, { Component } from 'react';

export default class App extends Component {
  constructor(props) {
    super(props);
    this.myInput = React.createRef();  
  }
  render() {
    return (
      <div>
        <input ref={this.myInput}/>

        <button onClick={() => {
          this.myInput.current.focus();
        }}>
          focus!
        </button>
      </div>
    );
  }
}

Calling the focus() method isn’t a React.js thing… it’s a normal JavaScript thing! 💃🏻💃🏻 For example, this is how it’s done with vanilla JavaScript:

document.getElementById('myInput').focus();

Controlling an HTML media element

You can also use React.createRef() and the standard JavaScript <video> API to control playback!

import React, { Component } from 'react';

export default class App extends Component {
  constructor(props) {
    super(props);
    this.myVideo = React.createRef();
  }
  render() {
    return (
      <div>
        <video ref={this.myVideo} width="320" height="176" controls>
          <source src="https://blender.com/big-buck-bunny.mp4" type="video/mp4" />
        </video>
        <div>
          <button onClick={() => {
            this.myVideo.current.play();
          }}>
            Play
          </button>
          <button onClick={() => {
            this.myVideo.current.pause();
          }}>
            Pause
          </button>
        </div>
      </div>
    );
  }
}

Refs with React Hooks Using useRef

Refs in React Hooks aren’t much different than class components. It’s achieved using the useRef hook. Just remember to omit this and you are golden 🙌

import React, { useRef } from "react";

function App() {

  const myInput = useRef(null);

  return (
    <div>
      <input ref={myInput}/>
      <button onClick={() => {
        myInput.current.focus();
      }}>
        focus!
      </button>
    </div>
  );
}

You can’t use createRef for pure functional components since they lack many of the React-y features like state & lifecycle components

✈️ Visit the React docs for detailed info about createRef().

Thanks for learning with the DigitalOcean Community. Check out our offerings for compute, storage, networking, and managed databases.

Learn more about us


About the authors
Default avatar
William Le

author

Still looking for an answer?

Ask a questionSearch for more help

Was this helpful?
 
Leave a comment


This textbox defaults to using Markdown to format your answer.

You can type !ref in this text area to quickly search our full set of tutorials, documentation & marketplace offerings and insert the link!

Try DigitalOcean for free

Click below to sign up and get $200 of credit to try our products over 60 days!

Sign up

Join the Tech Talk
Success! Thank you! Please check your email for further details.

Please complete your information!

Get our biweekly newsletter

Sign up for Infrastructure as a Newsletter.

Hollie's Hub for Good

Working on improving health and education, reducing inequality, and spurring economic growth? We'd like to help.

Become a contributor

Get paid to write technical tutorials and select a tech-focused charity to receive a matching donation.

Welcome to the developer cloud

DigitalOcean makes it simple to launch in the cloud and scale up as you grow — whether you're running one virtual machine or ten thousand.

Learn more
DigitalOcean Cloud Control Panel