How to use the “JavaScript function” Component

Last updated: Oct 2nd 2020

Barcode to PC allows you to manipulate the barcodes and the variables by executing JavaScript code.

Examples of what you can do with this component

  • Remove the first n characters from the barcode
  • Remove the last n characters from the barcode
  • Replace parts of the barcode
  • Extrapolate the data encoded inside the barcode

and the list goes on and on, you can use pretty much any combination of JavaScript methods to manipulate the strings. You can find the full list here.


Step 1 – Add the JAVASCRIPT FUNCTION Component
To do that, Drag & Drop the component from the Available components field to the Output components field by keeping pressed the left mouse button.

Step 2 – Write the JavaScript Function
Click on the component that you just added, and type the function that you want to be executed inside the JavaScript field.

Step 3 – Add variables
Every time you use a variable inside the JavaScript field you’ll have to insert a corresponding Output Component that will assign a value to that variable.

For example if you use the barcode variable, you’ll have to insert also a BARCODE component in the Output template field, otherwise, if you don’t do that the JavaScript component will fail and won’t be executed properly.

To prevent the BARCODE component affecting the Keyboard Emulation output you can click on it and enable the Skip output option.


Example 1
Let’s say that you want to remove the first character of the barcode

Initial barcode: 0897654321
Final output: 897654321

Follow these steps:

  • Add a JAVASCRIPT FUNCTION component just after the BARCODE component
  • Add this code in the JavaScript field: barcode.substr(1).
  • Enable the Skip output option of the BARCODE component

Example 2
Extrapolate parts of the barcode

Initial barcode: 433-0132-22
Final output: 0132

Use the same procedure of Example 1, but use this JavaScript code instead: barcode.split('-')[1]

Example 3
Replace a specific part of the barcode

Initial barcode: first_name:john;last_name:doe
Final output: name:john doe

Use the same procedure of Example 1, but use this JavaScript code instead: barcode.replace('first_name:','name:').replace('last_name:', ' ')

Tip 1: to remove a specific part of the barcode you can use the replace() method, and pass an empty string as second parameter, for example: barcode.replace('a', '')

Tip 2: you can use a regular expression as first parameter, for example barcode.replace(/w/gi, '') will perform a global, case-insensitive replacement of the w character.

Example 4
Extract a parameter from an URL

Initial barcode:
Final output: RN015215156

Use the same procedure of Example 1, but use this JavaScript code instead:
new URL(barcode).searchParams.get('tracking_id')


  1. Is it possible to create a menu to scan information from different sections of the warehouse or different pallets?

  2. I have writen a couple of JavaScript functions so that I can work out the human-readable text in the barcode Brazilian banks generate and I’m trying to use your app and server to “type” the code to the bank site. Problem is I can’t implement those functions in the JS FUNCTION component or, at least, I don’t know how! I can send my code for analysis or maybe get a few tips on ways to put more complex functions in the component. Thanks in advance!

  3. Como puedo hacer que los resultados del escaneo, salgan en diferentes columnas del Excel.

    Ahora mismo tengo todo en una misma casilla.

    Muchas gracias de antemano

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