qrcode.react

What is qrcode.react?

The qrcode.react npm package is a React component that uses the 'qrcode-generator' library to render QR codes as SVGs in React applications. It allows for easy creation and customization of QR codes directly within React components.

What are qrcode.react's main functionalities?

Generating a basic QR code

This feature allows you to generate a simple QR code by passing a string as the 'value' prop to the QRCode component.

{"import QRCode from 'qrcode.react';\n\nconst MyComponent = () => (\n  <QRCode value='http://facebook.github.io/react/' />\n);"}

Customizing the QR code

This feature enables customization of the QR code by setting props such as 'size' for dimension, 'bgColor' for background color, 'fgColor' for foreground color, and 'level' for error correction level.

{"import QRCode from 'qrcode.react';\n\nconst MyComponent = () => (\n  <QRCode\n    value='http://facebook.github.io/react/'\n    size={256}\n    bgColor={'#ffffff'}\n    fgColor={'#000000'}\n    level={'H'}\n  />\n);"}

Including a logo or image in the center of the QR code

This feature allows for the inclusion of a logo or image in the center of the QR code. The 'imageSettings' prop can be used to provide the image source and other related settings.

{"import QRCode from 'qrcode.react';\n\nconst MyComponent = () => (\n  <QRCode\n    value='http://facebook.github.io/react/'\n    size={256}\n    bgColor={'#ffffff'}\n    fgColor={'#000000'}\n    level={'H'}\n    includeMargin={true}\n    imageSettings={{\n      src: 'path/to/logo.png',\n      x: null,\n      y: null,\n      height: 24,\n      width: 24,\n      excavate: true,\n    }}\n  />\n);"}

Other packages similar to qrcode.react

qrcode

The 'qrcode' package is a more general QR code generator that can be used in both browser and server environments. It provides a wider range of options for generating QR codes, including output formats like PNG, UTF8, and others. Unlike qrcode.react, it is not specifically tailored for React and does not render as a React component.

react-qr-code

The 'react-qr-code' package is another React component for generating QR codes. It is similar to qrcode.react in that it is designed for React and renders QR codes as SVGs. However, it may have different customization options and dependencies.

react-native-qrcode-svg

The 'react-native-qrcode-svg' package is designed for React Native applications and allows for the generation of QR codes as SVG elements. It is similar to qrcode.react but is specifically built for the React Native environment rather than for web applications.

README

qrcode.react

A React component to generate QR codes for rendering to the DOM.

Installation

npm install qrcode.react

Usage

qrcode.react exports three components, supporting rendering as SVG or Canvas. SVG is generally recommended as it is more flexible, but Canvas may be preferable.

All examples are shown using modern JavaScript modules and syntax. CommonJS require('qrcode.react') is also supported.

QRCodeSVG

import ReactDOM from 'react-dom';
import {QRCodeSVG} from 'qrcode.react';

ReactDOM.render(
  <QRCodeSVG value="https://reactjs.org/" />,
  document.getElementById('mountNode')
);

QRCodeCanvas

import ReactDOM from 'react-dom';
import {QRCodeCanvas} from 'qrcode.react';

ReactDOM.render(
  <QRCodeCanvas value="https://reactjs.org/" />,
  document.getElementById('mountNode')
);

QRCode - DEPRECATED

Note: Usage of this is deprecated as of v3. It is available as the default export for compatiblity with previous versions. The renderAs prop is only supported with this component.

import ReactDOM from 'react-dom';
import QRCode from 'qrcode.react';

ReactDOM.render(
  <QRCode value="https://reactjs.org/" renderAs="canvas" />,
  document.getElementById('mountNode')
);

Available Props

prop	type	default value
value	string
renderAs	string ('canvas' 'svg')	'canvas'
size	number	128
bgColor	string (CSS color)	"#FFFFFF"
fgColor	string (CSS color)	"#000000"
level	string ('L' 'M' 'Q' 'H')	'L'
includeMargin	boolean	false
imageSettings	object (see below)

imageSettings

field	type	default value
src	string
x	number	none, will center
y	number	none, will center
height	number	10% of size
width	number	10% of size
excavate	boolean	false

Custom Styles

qrcode.react will pass through any additional props to the underlying DOM node (<svg> or <canvas>). This allows the use of inline style or custom className to customize the rendering. One common use would be to support a responsive layout.

Note: In order to render QR Codes in <canvas> on high density displays, we scale the canvas element to contain an appropriate number of pixels and then use inline styles to scale back down. We will merge any additional styles, with custom height and width overriding our own values. This allows scaling to percentages but if scaling beyond the size, you will encounter blurry images. I recommend detecting resizes with something like react-measure to detect and pass the appropriate size when rendering to <canvas>.

Encoding Mode

qrcode.react supports encoding text only, in a single segment. The encoding library being used does minimal detection to determine if the text being encoded can follow an optimized path for Numeric or Alphanumeric modes, allowing for more data to be encoded. Otherwise, it will encode following Byte mode. This mode includes supports multi-byte Unicode characters such as Kanji, however it does not support the optimized Kanji encoding mode.

LICENSE

qrcode.react is licensed under the ISC license.

qrcode.react bundles QR Code Generator, which is available under the MIT license.

Changelog

[3.0.0] - 2022-03-26

Added

• Added support for named exports for QRCodeSVG and QRCodeCanvas.
• Added support for ES Modules.
• Added embedded type definitions.

Changed

• Swapped out qr.js dependency for vendored version of https://www.nayuki.io/page/qr-code-generator-library.
• Rewrote using hooks.

Deprecated

• Deprecated support for default export. This will be removed in v4.

Removed

• Removed support for React < 16.8.