This FileMaker Pro file demonstrates the use of conditional formatting with a repeating field to draw the bars of a Code 39 (Code 3 of 9) barcode. This FileMaker Pro code 39 barcode generator uses a series of 16 “slots” per character which appear as wide or narrow bars. The intermediatebarcodeBitFlags field simply tells each repetition of the repeating field whether or not to use a background fill color, creating the bars.
For the repeating field to display properly, the width must be set to 1 pt for each repetition that’s displayed. You will need 32 repetitions for the start and end characters (16 for each), in addition to 16 repetitions for each of the characters in the input field. An auto-enter calculation is used on the input field to remove invalid characters.
The good news about having this in native FileMaker objects is that you can adjust as needed for your specific usage. For example, if you want thicker bars, you can just increase the width of the repeating field. If you're showing 200 repetitions, give it a try with a field width of 300, or 400. This will make the bars 50%, or 100% thicker than the original size.
The leading and trailing asterisk characters are required with Code 39 barcodes to indicate the direction of the barcode to the reader. These characters are not required with the "other" barcode plugin because that product supports only the Code 128 symbology instead of the Code 39 output. This alternate format could be implemented using the same bar/space methodology demonstrated in this file by changing the barcodeBitFlags calculation field to match the pattern in the bar/space column detailed online at:
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