scribbles_

Written by Yash Agrawal in San Francisco.

Dark Mode in React using SCSS

May 20, 2019 4 mins

In this article I have tried to explain my method of adding dark mode to a react app created using create-react-app and SCSS. This is my method and by no means do I claim it to be the best possible way of adding dark-mode to your react app.

The end goal is to add a dark mode button component which can be added anywhere in the project which on click switches to dark mode and back. It also keeps track of a users’ preference using localStorage - so if a user returns to the website using the same browser, the previously selected mode will directly be applied.

Let’s get started.

As per the official documentation, carry out the following steps:

npx create-react-app dark-mode
cd dark-mode
npm start

This will launch the react app on localhost:3000 and it should look like this.

Image 1

Now that we have the react app set up, we can start adding the dark mode. First, we will remove the styles set in App.css. Remove line 12 background-color: #282c34; and line 19 color: white;.

This is what it should look like:

Image 2

As mentioned in the title, we will use SCSS so that it is easy to scale the styling when you want to add more dark mode featured styles instead of merely flipping text and background.

npm install node-sass --save
# or
yarn add node-sass

Create a new file and name it style.scss. This is where we will add our color schemes for light and dark mode. Add the following snippet to the file.

$background-color-dark: #292A32;
$background-color-light: #FBFAF8;
$complimentary-color-dark: #393B43;
$complimentary-color-light: #FEFFFF;

body {
  background-color: $background-color-light;
  color: $background-color-dark;
}

body.dark-mode {
  background-color: $background-color-dark;
  color: $background-color-light;
}

Create another file called DarkModeToggle.js.This will be the main component where we will implement the dark mode toggle.

Add the following code to that file:

import React, { Component } from 'react';

import './style.scss';

class DarkModeToggle extends Component {
  constructor(props) {
    super(props);

    if(JSON.parse(localStorage.getItem('DARK_MODE')) === true) {
      document.body.classList.add('dark-mode');
    }

    this.state = {
      darkMode: JSON.parse(localStorage.getItem('DARK_MODE'))
    }

    this.handleModeChange = this.handleModeChange.bind(this);
  }

  handleModeChange() {
    if(!this.state.darkMode) {
      document.body.classList.add('dark-mode');
    } else {
      document.body.classList.remove('dark-mode');
    }

    this.setState({
      darkMode: (!this.state.darkMode)
    });
    localStorage.setItem('DARK_MODE', !this.state.darkMode);
  }

  render() {
    return (
      <button onClick={this.handleModeChange}>Change Mode</button>
    );
  }
}

export default DarkModeToggle;

Now, include this new DarkModeToggle component within the App.js. Include this component right below ‘Learn React’.

import React from 'react';
import logo from './logo.svg';
import './App.css';

import DarkModeToggle from './DarkModeToggle';

function App() {
  return (
    <div className="App">
      <header className="App-header">
        <img src={logo} className="App-logo" alt="logo" />
        <p>
          Edit <code>src/App.js</code> and save to reload.
        </p>
        <a
          className="App-link"
          href="https://reactjs.org"
          target="_blank"
          rel="noopener noreferrer"
        >
          Learn React
        </a>
        <DarkModeToggle/>
      </header>
    </div>
  );
}

export default App;

Now we have a very basic dark mode working. We can add more specific styles to dark mode in the style.scss.

Image 3

Here’s the source & demo.


Written by Yash Agrawal in San Francisco.