angularx-qrcode is a Ionic 3 and Angular4+ QR Code component/module library to generate QR Codes (Quick Response) in your Ionic and Angular 4+ app with support for AOT. It is a drop-in replacement for the no-longer-maintained angular2 component ng2-qrcode and based on qrcodejs.

angularx-qrcode supports AOT Compilation (Ahead-of-Time Compilation) which results in significant faster rendering. For further information see https://angular.io/guide/aot-compiler

npm install angularx-qrcode --save

yarn add angularx-qrcode

// all your imports
import { QRCodeModule } from 'angularx-qrcode';

@NgModule({
declarations: [
    AppComponent
],
imports: [
    QRCodeModule
],
providers: [],
bootstrap: [AppComponent]
})
export class AppModule { }

Now that Angular/Ionic knows about our QR Code module, we can invoke it from our template with a directive. If we use a simple text-string, we need no additional code in our controller.

<qrcode [qrdata]="'Your QR code data string'" [size]="256" [level]="'M'"></qrcode>

In addition to our <qrcode>-directive in example.html, we add two lines of code to our controller example.ts.

// example.ts:
export class QRCodeComponent {
    public angularxQrCode: string = '';
    // assign a value anywhere in/below your constructor
    this.angularxQrCode = 'Your QR code data string';
}

// example.html:
<qrcode [qrdata]="angularxQrCode" [size]="256" [level]="'M'"></qrcode>

Depending on the size of the qrdata to encode, a minimum size might be required.

MIT License

Based on no-longer-maintained angular2 component https://github.com/PragmaticClub/ng2-qrcode