How can I pass a Buffer to bwip-js?

[Ivan Bliskavka]

I need to create a Datamatrix from the following buffer using bwip-js.

02 00 25 4f b2 03 11 44  75 73 74 69 6e 20 4a 61  | ~~%O~~~Dustin Ja |
6d 65 73 20 42 75 63 6b                           | mes Buck~~~~~~~~ |

(Vendor Generated Barcode)

The closest I was able to get to was using latin1 encoding.

bwipjs.toCanvas(`canvas`, {
      bcid: 'datamatrix',
      text: buffer.toString('latin1)
});

When I read back the generated Datamatrix, I get the following result

02 00 25 4f c2 b2 03 11  44 75 73 74 69 6e 20 4a  | ~~%O~~~~Dustin J |
61 6d 65 73 20 42 75 63  6b                       | ames Buck        |

(Generated with bwip-js)

There is an extra c2 at index 4. I think maybe it has to do with non printable characters at indexes 0-7. That segments represents a date in a custom vendor format.

Is there a way to pass a raw buffer to bwip-js?

[metafloor]

Very timely issue as this usage has only been supported in releases from just a couple of weeks ago. Convert the buffer to 'binary' string and set binarytext:true on the options object you pass in:

bwipjs.toCanvas(`canvas`, {
      bcid: 'datamatrix',
      text: buffer.toString('binary'),
      binarytext: true,
});

You must use version 3.4.5 or 4.0.0+.

[Ivan Bliskavka]

Thank you for the quick response. I installed the latest package and tried as you suggested.

I am still getting the exact same Datamatrix as before with latin1

[Ivan Bliskavka]

There may be a bug somewhere. I used binary encoding on a buffer, with binarytext. I then read the generated Datamatrix using the online tool listed below. The data read by the tool was different than what was submitted to bwip-js.

  it('compare binary encoding input with output', () => {
    const data = Buffer.from(
      '0200254fb2031144757374696e204a616d6573204275636b',
      'hex'
    );
    const binaryEncoded = data.toString('binary');

    // Generate a data matrix using bwip-js@4 with binarytext=true

    // Read generated barcode using: https://online-barcode-reader.inliteresearch.com/

    // Generated Datamatrix has a extra `c2` at position 8
    const bwip = Buffer.from(
      '0200254fc2b2031144757374696e204a616d6573204275636b',
      'hex'
    );

    console.log({
      expected: binaryEncoded,
      dataMatrix: bwip.toString('binary'),
    });
  });

Result

    {
      expected: '\x02\x00%O²\x03\x11Dustin James Buck',
      dataMatrix: '\x02\x00%O²\x03\x11Dustin James Buck'
    }

I should be able to extract the original text from the Datamatrix.

[metafloor]

Found the issue. Mistakenly marked binarytext as a bwip-js option but it is needed by the BWIPP wrapper code. Fixed in 4.0.1.

[Ivan Bliskavka]

Thank you very much for the quick response! I confirmed the output is as expected, you may close this issue.

❤️