barcode.js

return {

    scannerAvailable: false,

    scanner: null,

    isEnabled: function() {
      if ('plugins' in window && 'barcodeScanner' in window.plugins) {
        scanner = window.plugins.barcodeScanner;
      }
      else if ('barcodeScanner' in window) {
        scanner = window.barcodeScanner;
      }
      else if ('cordova' in window) {
        // barcodeScanner 1.0
        if ('plugins' in cordova && 'barcodeScanner' in cordova.plugins) {
          scanner = cordova.plugins.barcodeScanner;
        // barcodeScanner 0.7
        } else {
          scanner = cordova.require("cordova/plugin/BarcodeScanner");
        }
      }
      if (scanner != null) {
        this.scannerAvailable = true;
      }

      return this.scannerAvailable;
    }, 
}