Dfx-qrcode NPM

dfx-qrcode

dfx-qrcode is a tiny and simple-to-use Angular QR-Code generator library.

Features

ESM Module based
Tiny (~ 5.9kB minified + gzipped)
Accessible
Server Side Rendering (Angular Universal)
Standalone Component API
Supports Canvas, PNG and SVG

Version compatibility

Angular	dfx-qrcode
17.x.x	2.x.x
16.x.x	1.x.x

Installation

npm
```
npm install dfx-qrcode
```
pnpm
```
pnpm install dfx-qrcode
```

Usage

Standalone Components

import { QrCodeComponent } from 'dfx-qrcode';

@Component({
  standalone: true,
  selector: 'app-root',
  template: ` <qrcode data="hello" /> `,
  imports: [QRCodeComponent],
})
export class AppComponent {}

Module

import { QRCodeComponent } from 'dfx-qrcode';

@NgModule({
  declaration: [AppComponent],
  imports: [QRCodeComponent],
})
export class AppModule {}

@Component({
  selector: 'app-root',
  template: ` <qrcode data="hello" /> `,
})
export class AppComponent {}

Configuration

Standalone Components

import {
  provideQRCode,
  QRCodeComponent,
  withAllowEmptyString,
  withColorDark,
  withColorLight,
  withElementType,
  withErrorCorrectionLevel,
  withImage,
  withImageHeight,
  withImageSrc,
  withImageWidth,
  withMargin,
  withSize,
  withVersion,
} from 'dfx-qrcode';

@Component({
  // ...
  standalone: true,
  imports: [QRCodeComponent],
  providers: [
    provideQRCode(
      withAllowEmptyString(false),
      withColorDark('#000000'),
      withColorLight('#FFFFFF'),
      withCssClass('qrcode'),
      withElementType('img'),
      withErrorCorrectionLevel('L'),
      withMargin(4),
      withImage(withImageSrc('assets/logo.png'), withImageWidth(40), withImageHeight(40)),
      withVersion(-1),
      withSize(5),
    ),
  ],
  template: ` <qrcode data="hello" /> `,
  // ...
})
export class AppComponent {}

Module

import {
  provideQRCode,
  QRCodeComponent,
  withAllowEmptyString,
  withColorDark,
  withColorLight,
  withElementType,
  withErrorCorrectionLevel,
  withImage,
  withImageHeight,
  withImageSrc,
  withImageWidth,
  withMargin,
  withSize,
  withVersion,
} from 'dfx-qrcode';

@NgModule({
  declaration: [AppComponent],
  imports: [QRCodeComponent],
  providers: [
    provideQRCode(
      withAllowEmptyString(false),
      withColorDark('#000000'),
      withColorLight('#FFFFFF'),
      withCssClass('qrcode'),
      withElementType('img'),
      withErrorCorrectionLevel('L'),
      withMargin(4),
      withImage(withImageSrc('assets/logo.png'), withImageWidth(40), withImageHeight(40)),
      withVersion(-1),
      withSize(5),
    ),
  ],
})
export class AppModule {}

On component usage

@Component({
  // ...
  selector: 'app-root',
  template: `
    <qrcode
      [data]="'hello'"
      [allowEmptyString]="true"
      [elementType]="'img'"
      [errorCorrectionLevel]="'L'"
      [ariaLabel]="'Description of QR-Code'"
      [title]="'Description of QR-Code'"
      [alt]="'Description of QR-Code'"
      [cssClass]="'qrcode'"
      [colorDark]="'#000000'"
      [colorLight]="'#FFFFFF'"
      [margin]="4"
      [size]="5"
      [version]="-1"
      [imageSrc]="'assets/logo.png'"
      [imageWidth]="40"
      [imageHeight]="40"
    />
  `,
  // ...
})
export class AppComponent {}

Parameters

Name	Type	Default value	Description
allowEmptyString	`boolean`	`false`	Define if empty or undefined strings should be converted to a space (" ") or throw an error.
elementType	`'img' \\| 'canvas' \\| 'svg'`	`img`	Define if the QR-Code should be rendered as HTMLImageElement or HTMLCanvasElement
errorCorrectionLevel	`'L' \\| 'M' \\| 'Q' \\| 'H'`	`L`	Define the error correction level
cssClass	`string`	`qrcode`	Define a css class for the wrapper element of the QR-Code
colorDark	`Hex color`	`#000000`	Define the color of the dark elements
colorLight	`Hex color`	`#FFFFFF`	Defined the color of the light elements
margin	`number`	`4`	Define the margin around the QR-Code in px
size	`number`	`5`	Define the size of the modules of the QR-Code in px
version	`number`	`-1`	Define the QR-Code version. `-1` means auto-select
ariaLabel	`string \\| undefined`	`undefined`	String which should be set as aria-label tag
title	`string \\| undefined`	`undefined`	String which should be set as title tag
alt	`string \\| undefined`	`undefined`	String which should be set as alt tag
imageSrc	`string \\| undefined`	`undefined`	Path to image displayed in the QR-Code center
imageHeight	`number \\| undefined`	`undefined`	Height of center image in px
imageWidth	`number \\| undefined`	`undefined`	Width of center image in px

Error correction level

Error correction capability allows to successfully scan a QR Code even if the symbol is dirty or damaged. Four levels are available to choose according to the operating environment.

Higher levels offer a better error resistance but reduce the symbol's capacity. If the chances that the QR Code symbol may be corrupted are low (for example if it is showed through a monitor) is possible to safely use a low error level such as Low or Medium.

Possible levels are shown below:

Level	Error resistance
L (Low)	~7%
M (Medium)	~15%
Q (Quartile)	~25%
H (High)	~30%

The percentage indicates the maximum amount of damaged surface after which the symbol becomes unreadable.

If not specified, the default value is L.

QR Code capacity

Capacity depends on symbol version and error correction level. Also encoding modes may influence the amount of storable data.

The QR Code versions range from version 1 to version 40. Each version has a different number of modules (black and white dots), which define the symbol's size. For version 1 they are 21x21, for version 2 25x25 e so on. Higher is the version, more are the storable data, and of course bigger will be the QR Code symbol.

The table below shows the maximum number of storable characters in each encoding mode and for each error correction level.