Code128 Barcode in Adobe Acrobat Form Text Field

Question

We have a PDF form where you fill out product options then it converts those options into a single text field "Lot Number" then finally a field, "Lot Number Barcode", takes the lot number and converts it to a barcode. For some reason this is not working. I know almost nothing about barcode integration but I am a programmer and just looking for some guidance on this topic.

The "Lot Number Barcode" field uses under properties Calculate->Custom Calculation Script this code. So like I said above it's taking the "Lot Number" field and converting to a string which I believe then the font uses to generate the correct barcode or that is the idea.

event.value = this.getField("Lot No").valueAsString;

Here is a link to the actual PDF I was given from the client:
https://ufile.io/ihh87

This is what I have found out on this topic but obviously still missing pieces to the puzzle and hope someone can give me the exact steps needed to get this working in Acrobat Pro.

1. I need an embeddable CODE 128 font? I found this font set but costs $159 is there a free version that I could use and have it still work? https://www.idautomation.com/barcode-fonts/code-128/
2. Javascript - I need to add custom Javascript code to the Actions properties of the "Lot Number Barcode" text field but I don't know which code needs to be implemented and looking for a resource on this to better explain the process.
3. Font height and font size - If I get the previous 2 steps working I still need to be concerned with setting the PDF text field to an exact font size and height otherwise the barcode scanner could error out. Is this true? Currently the PDF text field font size is set to "Auto"

Answer 1

Code 128 is a relatively complex barcode, and can not be represented by replacing the string to be displaced with a font. Therefore, you will need some logic to assemble the correct string to display. I am not aware of anything available publicly which would do that calculation; you'd be on your own or have to find someone helping.

In order to create that logic, you'd have to understand how Code 128 works; this information should be freely available.

Concerning the font licence, you might compare its cost with the other solutions: try to work with the free font floating around, or create your own font, or use graphics (for example in an annotation, which can be calculated using Acrobat JavaScript). At the end of the day, even that rather expensive font may be the most economic solution.

As you already have studied the specification for Code 128, you will also have seen the requirements to print it. You will have to make your adjustments with the field, and most likely have to set a fixed font size. This will, however, depend on the scaling happening when printing the page.

Answer 2

You can try the Libre Code128 font (free) at https://fonts.googleapis.com/css?family=Libre+Barcode+128+Text, and the attached JavaScript code to calculate the checksum.

var buttonGen = document.getElementById("btnGen");
buttonGen.onclick = function () {
  var x = document.getElementById("textIn").value;
  var i, j, intWeight, intLength, intWtProd = 0, arrayData = [], fs;
  var arraySubst = [ "Ã", "Ä", "Å", "Æ", "Ç", "È", "É", "Ê" ];

/*
 * Checksum Calculation for Code 128 B
 */
  intLength = x.length;
 arrayData[0] = 104; // Assume Code 128B, Will revise to support A, C and switching.
 intWtProd = 104;
 for (j = 0; j < intLength; j += 1) {
   arrayData[j + 1] = x.charCodeAt(j) - 32; // Have to convert to Code 128 encoding
   intWeight = j + 1; // to generate the checksum
   intWtProd += intWeight * arrayData[j + 1]; // Just a weighted sum
 }
 arrayData[j + 1] = intWtProd % 103; // Modulo 103 on weighted sum
 arrayData[j + 2] = 106; // Code 128 Stop character
  chr = parseInt(arrayData[j + 1], 10); // Gotta convert from character to a number
  if (chr > 94) {
    chrString = arraySubst[chr - 95];
  } else {
    chrString = String.fromCharCode(chr + 32);
  }
  
  // Change the font-size style to match the drop down
  fs = document.getElementsByTagName("option")[document.getElementById("selList").selectedIndex].value;
  document.getElementById("test").style.fontSize = fs  + 'px';
  
  document.getElementById("check").innerHTML =
    'Checksum = ' + chr + ' or character ' + // Make It Visual
    chrString + ', for text = "' + x + '"';
  
  document.getElementById("test").innerHTML =
    'Ì' + // Start Code B
    x + // The originally typed string
    chrString + // The generated checksum
    'Î'; // Stop Code
}

<html>
  <head>
    <link href="https://fonts.googleapis.com/css?family=Libre+Barcode+128+Text" rel="stylesheet">
    <style>
      td, th {
        text-align: center;
        padding: 6px;
      }

      .ss {
        font-family: 'Libre Barcode 128 Text', cursive;
        font-size: 24px;
      }
    </style>
  </head>
  <body>
    &nbsp;Font Size:&nbsp;
    <select id="selList">
      <option value="24" selected>24px</option>
      <option value="30">30px</option>
      <option value="36">36px</option>
      <option value="42">42px</option>
      <option value="48">48px</option>
      <option value="54">54px</option>
      <option value="60">60px</option>
      <option value="66">66px</option>
      <option value="72">72px</option>
      <option value="78">78px</option>
      <option value="84">84px</option>
      <option value="90">90px</option>
      <option value="96">96px</option>
    </select>&nbsp;

    <input type="text" id="textIn"></input>
    <input type="button" id="btnGen" value="Generate Code 128 Checksum" tabindex=4/>
    <div id="check"></div><br /><span id="test" class="ss">ÌMaking the Web Beautiful!$Î</span><br />
    <p>This is a demonstration of use of the Libre Barcode 128 Font.</p>
    <p>Because the Libre Barcode Code 128 font does not generate checksums, you need this component to produce a scanning barcode.</p>
    <p>To use, just enter the text you want to embed in the barcode and press the generate button. Happy barcoding!</p>
    <p>By the way, Libre Barcode 128 Font uses the following high ASCII / unicode characters to implement the control codes symbols. (This is essentially adding 100 to the value, in other words 'Ã' is U+00C3 (195) to 'Î' is U+00CE (206).)</p>
<table border="3">
    <tr>
    <th>Value</th>
    <th>Encoding</th>
    <th>Subst</th>
  </tr>
<tr><td> 95</td><td>A: US, B: DEL, C: 95</td><td>Ã</td></tr>
<tr><td> 96</td><td>A: FNC 3, B: FNC 3, C: 96</td><td>Ä</td></tr>
<tr><td> 97</td><td>A: FNC 2, B: FNC 2, C: 97</td><td>Å</td></tr>
<tr><td> 98</td><td>A: Shift B, B: Shift A, C: 98</td><td>Æ</td></tr>
<tr><td> 99</td><td>A: Code C, B: Code C, C: 99</td><td>Ç</td></tr>
<tr><td>100</td><td>A: Code B, B: FNC 4, C: Code B</td><td>È</td></tr>
<tr><td>101</td><td>A: FNC 4, B: Code A, C: Code A</td><td>É</td></tr>
<tr><td>102</td><td>A: FNC 1, B: FNC 1, C: FNC 1</td><td>Ê</td></tr>
<tr><td>103</td><td>Begin Code A</td><td>Ë</td></tr>
<tr><td>104</td><td>Begin Code B</td><td>Ì</td></tr>
<tr><td>105</td><td>Begin Code C</td><td>Í</td></tr>
<tr><td>106</td><td>Stop Code</td><td>Î</td></tr></table>
  </body>
</html>

In order to get a Code 128 barcode to print and scan, a checksum needs to be calculated. This involves calculating a weighted sum of the contents of Lot Number and deriving its remainder of division by 103.

Answer 3

The libre barcode128 font seems to be a open source copy of the ID family of barcode fonts. So the character codes may match.

Optimized 128 codes (which switch between Code128B and 128C to allow for shorter barcodes if consecutive digits are used in the input string) will not be very human readable, so using them with the font that includes human readable characters will not give great results because the Code128C encoding (For numbers) will mangle consecutive numbers.

I found this librebarcode project on github where someone used a big javascript array with the character maps for the font and the weights you should use for the calculation of the checksum.

Together with the example code and the wikipedia page for code 128 you should be able to get something working in Acrobat.

Here is the array:

var data = [
      // the unicode chars are from:
      //   www.idautomation.com/barcode-fonts/code.128/user-manual.html
      //   http://www.jtbarton.com/Barcodes/Code128.aspx
      // checksum value, pattern, canonical id/name (based on Code Set B)
      // (name of the glyph in the font?), [unicode chars], textbelow_flag_or_charcodes
      [   0, ' ', ' ', '00', 'Â']
    , [   1, '!', '!', '01', '!']
    , [   2, '"', '"', '02', '"']
    , [   3, '#', '#', '03', '#']
    , [   4, '$', '$', '04', '$']
    , [   5, '%', '%', '05', '%']
    , [   6, '&', '&', '06', '&']
    , [   7, "'", "'", "07", "'"]
    , [   8, '(', '(', '08', '(']
    , [   9, ')', ')', '09', ')']
    , [  10, '*', '*', '10', '*']
    , [  11, '+', '+', '11', '+']
    , [  12, ',', ',', '12', ',']
    , [  13, '-', '-', '13', '-']
    , [  14, '.', '.', '14', '.']
    , [  15, '/', '/', '15', '/']
    , [  16, '0', '0', '16', '0']
    , [  17, '1', '1', '17', '1']
    , [  18, '2', '2', '18', '2']
    , [  19, '3', '3', '19', '3']
    , [  20, '4', '4', '20', '4']
    , [  21, '5', '5', '21', '5']
    , [  22, '6', '6', '22', '6']
    , [  23, '7', '7', '23', '7']
    , [  24, '8', '8', '24', '8']
    , [  25, '9', '9', '25', '9']
    , [  26, ':', ':', '26', ':']
    , [  27, ';', ';', '27', ';']
    , [  28, '<', '<', '28', '<']
    , [  29, '=', '=', '29', '=']
    , [  30, '>', '>', '30', '>']
    , [  31, '?', '?', '31', '?']
    , [  32, '@', '@', '32', '@']
    , [  33, 'A', 'A', '33', 'A']
    , [  34, 'B', 'B', '34', 'B']
    , [  35, 'C', 'C', '35', 'C']
    , [  36, 'D', 'D', '36', 'D']
    , [  37, 'E', 'E', '37', 'E']
    , [  38, 'F', 'F', '38', 'F']
    , [  39, 'G', 'G', '39', 'G']
    , [  40, 'H', 'H', '40', 'H']
    , [  41, 'I', 'I', '41', 'I']
    , [  42, 'J', 'J', '42', 'J']
    , [  43, 'K', 'K', '43', 'K']
    , [  44, 'L', 'L', '44', 'L']
    , [  45, 'M', 'M', '45', 'M']
    , [  46, 'N', 'N', '46', 'N']
    , [  47, 'O', 'O', '47', 'O']
    , [  48, 'P', 'P', '48', 'P']
    , [  49, 'Q', 'Q', '49', 'Q']
    , [  50, 'R', 'R', '50', 'R']
    , [  51, 'S', 'S', '51', 'S']
    , [  52, 'T', 'T', '52', 'T']
    , [  53, 'U', 'U', '53', 'U']
    , [  54, 'V', 'V', '54', 'V']
    , [  55, 'W', 'W', '55', 'W']
    , [  56, 'X', 'X', '56', 'X']
    , [  57, 'Y', 'Y', '57', 'Y']
    , [  58, 'Z', 'Z', '58', 'Z']
    , [  59, '[', '[', '59', '[']
    , [  60, '\\', '\\', '60', '\\']
    , [  61, ']', ']', '61', ']']
    , [  62, '^', '^', '62', '^']
    , [  63, '_', '_', '63', '_']
    , [  64, 'NUL', '`', '64', '`']
    , [  65, 'SOH', 'a', '65', 'a']
    , [  66, 'STX', 'b', '66', 'b']
    , [  67, 'ETX', 'c', '67', 'c']
    , [  68, 'EOT', 'd', '68', 'd']
    , [  69, 'ENQ', 'e', '69', 'e']
    , [  70, 'ACK', 'f', '70', 'f']
    , [  71, 'BEL', 'g', '71', 'g']
    , [  72, 'BS', 'h', '72', 'h']
    , [  73, 'HT', 'i', '73', 'i']
    , [  74, 'LF', 'j', '74', 'j']
    , [  75, 'VT', 'k', '75', 'k']
    , [  76, 'FF', 'l', '76', 'l']
    , [  77, 'CR', 'm', '77', 'm']
    , [  78, 'SO', 'n', '78', 'n']
    , [  79, 'SI', 'o', '79', 'o']
    , [  80, 'DLE', 'p', '80', 'p']
    , [  81, 'DC1', 'q', '81', 'q']
    , [  82, 'DC2', 'r', '82', 'r']
    , [  83, 'DC3', 's', '83', 's']
    , [  84, 'DC4', 't', '84', 't']
    , [  85, 'NAK', 'u', '85', 'u']
    , [  86, 'SYN', 'v', '86', 'v']
    , [  87, 'ETB', 'w', '87', 'w']
    , [  88, 'CAN', 'x', '88', 'x']
    , [  89, 'EM', 'y', '89', 'y']
    , [  90, 'SUB', 'z', '90', 'z']
    , [  91, 'ESC', '{', '91', '{']
    , [  92, 'FS', '|', '92', '|']
    , [  93, 'GS', '}', '93', '}']
    , [  94, 'RS', '~', '94', '~']
    , [  95, 'US', 'DEL', '95 ', 'Ã']
    , [  96, 'FNC 3', 'FNC 3', '96', 'Ä']
    , [  97, 'FNC 2', 'FNC 2', '97', 'Å']
    , [  98, 'Shift B', 'Shift A', '98', 'Æ']
    , [  99, 'Code C', 'Code C', '99', 'Ç']
    , [ 100, 'Code B', 'FNC 4', 'Code B', 'È']
    , [ 101, 'FNC 4', 'Code A', 'Code A', 'É']
    , [ 102, 'FNC 1', 'FNC 1', 'FNC 1', 'Ê']
    , [ 103, 'Start Code A', 'Start Code A', 'Start Code A', 'Ë']
    , [ 104, 'Start Code B', 'Start Code B', 'Start Code B', 'Ì']
    , [ 105, 'Start Code C', 'Start Code C', 'Start Code C', 'Í']
    , [ 206, 'Stop', 'Stop', 'Stop', 'Î']
    ]
;

My own semi-working experiment is up on GitHub if you want to try.

Answer 4

Having a similar problem and I found a solution. If you update the link to your pdf file from the client I would be happy to try it.

In MS Word you can easily get the Code128 from any input string. I imported the pdf form into Word using FineReader, where I selected form as a background image, added the fields, and then added Code128 which is built-in into Word. Pretty good result.