Use Checksum and Supplement Data for Barcodes in PHP

 # Instantiate barcode object

$bb = new BarCodeBuilder();

\# Set the Code text for the barcode

$bb->setCodeText("1234567");

\# Set the symbology type to Code39

$symbology=new Symbology();

$bb->setSymbologyType($symbology->Code39Standard);

\# Make the checksum to be visible on the barcode

$enableChecksum=new EnableChecksum();

$bb->setEnableChecksum($enableChecksum->Default);

\# Save the image to disk in JPG format

$bb->save($dataDir . "barcode.jpg");

\# Print message

print "Barcode image generated successfully.".PHP_EOL;