ng-qrcode

Angular QR Code Generator

Easy to use Ivy compatible QR code generator for Angular projects.

Features:

• Compatible with Angular 12
• Leverages the widely used qrcode package to do the heavy lifting
• Renders to HTML Canvas

Change Log

Installation

Add as a dependency to your angular application:

npm install ng-qrcode --save

Usage

Import into your consuming module (Eg: AppModule):

 import { QrCodeModule } from 'ng-qrcode';
 
 @NgModule({
   imports: [
     QrCodeModule
   ]
 })

Component

<qr-code value="Yo world!" size="300" errorCorrectionLevel="M"></qr-code>

value: string (required)

The value to encode in the QR code, eg: a url

size: string | number (optional)

An optional size in pixels to render at

Default: automatic size based on the value provided (recommended)

errorCorrectionLevel: string (optional)

Controls the amount of redundant information included to make the QR code more likely to scan correctly if it is dirty / damaged

Default: "M"

Valid values: "L", "M", "Q", "H" - where "L" is the lowest amount of redundancy, and "H" is the highest

See: https://www.npmjs.com/package/qrcode#error-correction-level for further details

centerImageSrc: string (optional)

A URI suitable to use an a Image src property to load and render in the center of the QR code.

Note: the image will obscure part of the QR code, and therefore you should err on the side of a higher error correction level, anecdotally when the size is less than 1/4 of the size of the code, with at least "M" error correction, it is generally still scannable.

centerImageSize: string | number (optional)

An optional size in pixels to render the center image.

Default: 60

margin: number (optional)

An optional amount of margin to be rendered within the canvas element. Defaults to 4, where the unit is the size of one "dot" in the QR code.

Directive

If the provided component is not flexible enough for you, there is also a directive provided that is used by the component under the hood, which provides finer grain control.

Demo

See running demo here

A demo app is included in the repository under projects/ng-qrcode-demo which can be run locally using ng build && ng serve

Known/Common Issues

Reference Error 'global' is not defined

Essentially in some cases Angular will bundle a version of the buffer library that is not compatible with web browsers if the 'global' object is not defined.

This can be easily worked around, see comment here for options: https://github.com/mnahkies/ng-qrcode/issues/2#issuecomment-563414305

Footnote / Package History

Pre-version 2.0.0 this package was developed by emin93 and used the qrious npm package to generate the QR Codes.

The source for this was lost, and this repository is a re-write, first released as v2.0.0 that uses the qrcode npm package to generate QR Codes.

v2.0.0 should be backwards compatible, aside from a rename of the exported NgModule from QRCodeModule -> QrCodeModule for consistency.

Changelog

5.1.0 - 2021-10-03

• Support configuring margin around the qr code (rendered within the canvas element)