How to use the JAVASCRIPT_FUNCTION Component

Last updated: Sep 4th 2021

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.

Setup

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.

Examples

 
 
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: https://example.com/?user_id=123&tracking_id=RN015215156&order_id=456
Final output: RN015215156

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


Filippo

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