ng qrcode

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

mnahkies
56
10
TypeScript

Angular QR Code Generator

Build Status
npm

Easy to use QR code generator for Angular projects.

Features:

  • Compatible with Angular 18
  • 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="Hello world!" 
         size="300" 
         errorCorrectionLevel="M" />

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)

darkColor: RGBAColor (optional)

An RGBA Hex string to use as the color for the dark / filled modules.
If an invalid value is passed, the default will be used.

Default black (“#000000FF”)

lightColor: RGBAColor (optional)

An RGBA Hex string to use as the color for the empty space.
If an invalid value is passed, the default will be used.

Default white (“#FFFFFFFF”)

style: { [klass: string]: any; } (optional)

Inline style object, passed to the inner canvas element as [ngStyle]

styleClass: string (optional)

CSS Class, passed to the inner canvas element

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

Angular compatibility matrix

See table below for a history of versions and their Angular compatibility.

From version 16 onwards the library major version will match the Angular
major version.

Angular Version ng-qrcode Versions
^18 ^18
^17 ^17
^16 ^16
^15 ^8
^14 ^7
^13 ^6
^12 ^5
^10 / ^11 ^4
^7 / ^8 ^3
^7 ^2

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.