Barcode Detector Api Polyfill using zbar.wasm

How to use

This is a very simple polyfill using zbar.wasm under the hood written in plain ES6.

You can install the polyfill with BarcodeDetectorPolyfill.setupPolyfill().

<script type="module">
  import BarcodeDetectorPolyfill from "./BarcodeDetectorPolyfill.min.js";

  console.log("Native api support", BarcodeDetectorPolyfill.checkBarcodeDetectorSupport());
  BarcodeDetectorPolyfill.setupPolyfill();
</script>

Simply use like the regular api (check https://developer.mozilla.org/en-US/docs/Web/API/Barcode_Detection_API).

zbar.wasm

This polyfill uses zbar.wasm and therefore needs to load a ~200kb bin file in order to work. The polyfill itself is 9.5kb.

Checking secure context

Webcam is only available in a secure context. Here is some sample code to help you (using Swal to show an error message).

if (!BarcodeDetectorPolyfill.checkWebcamSupport()) {
  if (!BarcodeDetectorPolyfill.checkSecureContext()) {
    Swal.fire("You need a secure context!");
  } else {
    Swal.fire("No webcam connected!");
  }
}

You can try the demo

Running npm run start and see demo.html or https://codepen.io/lekoalabe/pen/abyrqaL (currently not working due to CORS issue loading the wasm file)

Also check out

Other

• https://zbar-wasm.github.io/demo/

Api ref

• https://developer.mozilla.org/en-US/docs/Web/API/Barcode_Detection_API
• https://developer.mozilla.org/en-US/docs/Web/API/MediaDevices/getUserMedia

Scanner app

• https://github.com/mebjas/html5-qrcode
• https://github.com/maslick/koder

Zbar

• https://github.com/samsam2310/zbar.wasm
• https://github.com/mchehab/zbar

Zxing

• https://github.com/zxing-js/browser

Other libs

• https://www.npmjs.com/package/qr-scanner (worker support)
• https://serratus.github.io/quaggaJS/ (nice rotation algo)
• https://github.com/ericblade/quagga2

Other polyfills

• https://github.com/giladaya/barcode-detector-polyfill
• https://github.com/gruhn/barcode-detector