Table of Contents

• Table of Contents
• Presentation
• Bitgener Online Demo
• Installation
• Technical information
  • Node.js
  • Debugging
  • Tests
    • Linting
    • Unit
• Supported symbologies
• Usage
  • Library
    • Import Bitgener
    • bitgener(options): AsyncFunction
    • Examples
      • 1D barcode
      • 2D barcode
      • Full example using Sharp
  • Environment variables
  • Errors
    • Object structure
    • Codes
• Code of Conduct
• Contributing
• Support
• Security
• License

Presentation

Bitgener is a barcode generator written in pure Node.js using ES6 and ES7 features. It is based on the great work made by Jean-Baptiste Demonte and contributors: barcode.

Despite the fact that bwipjs can generate a lot of barcodes and other libraries exist, I personally needed to generate the same ECC 200 compliant Datamatrixes from the barcode library and it was not possible by any of these libraries. Plus I had some issues with architecture-dependent image processor libraries used by other modules.

Bitgener generates barcodes in pure SVG (Scalable Vector Graphics) format. The barcode generated can be a buffer, a readable stream, a string representing SVG tags content or a file. It adds features like background and bars opacity, fixing final image width and height, keeping the original 1D/2D size, adding paddings and a generic font family for hri, adding stream, buffer and file outputs with a specific encoding.

SVGs generated by Bitgener uses crisp edges shape rendering to tell the user agent to turn off anti-aliasing to preserved the contrast, colors and edges without any smoothing or blurring that applies to images scaled up or down. Browsers support is nice and can be found here: https://caniuse.com/#feat=css-crisp-edges.

The aim of this project is to provide a simple, lightweight, zero-dependencies and fast barcode generator and let user choose the external or native image processing library to transform the SVG generated into the specific format if needed.

Bitgener Online Demo

Show me!

Installation

npm install bitgener

npm i -S bitgener

Technical information

Node.js

• Language: JavaScript ES6/ES7
• VM: Node.js >=10.0.0

Debugging

• Own debugger embedded that writes on process.stderr when the DEBUG environment variable is set. See Environment variables.

Tests

Linting

ESLint with Airbnb base rules. See Airbnb JavaScript Style Guide.

npm run lint

Unit

Mocha and Chai.

npm test

Supported symbologies

One dimension:

• Codabar
• Code 11
• Code 39
• Code 93
• Code 128
• Ean 8
• Ean 13
• Standard 2 of 5
• Interleaved 2 of 5
• MSI
• UPC

Two dimensions:

• DataMatrix (ECC 200 standard, square and rectangular)

Usage

Library

Import Bitgener

Bitgener module exports one async function named bitgener.

const bitgener = require('bitgener');

bitgener(options): AsyncFunction

• options<Object>:

  • data* <String> The data to encode.
  • type* <String> The supported symbology in which data will be encoded.
    • codabar: each character to encode must be one of 0123456789-$:/.+
    • code11: each character to encode must be one of 0123456789-
    • code39: each character to encode must be one of 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ-. $/+%
    • code93: each character to encode must be one of 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ-. $/+%
    • code128: each character to encode must be one of !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~
    • ean8: data to encode must contain 7 numerical digits.
    • ean13: data to encode must contain 12 numerical digits.
    • std25 (standard 2 of 5): data to encode must contain only numerical digits.
    • int25 (interleaved 2 of 5): data to encode must contain only numerical digits.
    • msi: data to encode must contain only numerical digits.
    • upc: data to encode must contain 11 numerical digits.
    • datamatrix: data to encode has no restrictions.
  • output <String> The output format for the svg property of the object returned by this function. Default: stream
    • stream: generated SVG tags as a Readable Stream.
    • string: generated SVG tags as a string.
    • buffer: generated SVG tags as a Buffer.
    • {path to a file}: a valid path to a SVG file. The file will be created or overwritten, eg.: './docs/bitgener.svg'.
  • encoding <String> For stream, buffer and file outputs. Default: utf8
    • utf8: multibyte encoded Unicode characters. Many web pages and other document formats use UTF-8.
    • ascii: for 7-bit ASCII data only. This encoding is fast and will strip the high bit if set.
    • utf16le: 2 or 4 bytes, little-endian encoded Unicode characters. Surrogate pairs (U+10000 to U+10FFFF) are supported.
    • ucs2: alias of 'utf16le'.
    • base64: base64 encoding. When creating a Buffer from a string, this encoding will also correctly accept "URL and Filename Safe Alphabet" as specified in RFC4648, Section 5.
    • latin1: a way of encoding the Buffer into a one-byte encoded string (as defined by the IANA in RFC1345, page 63, to be the Latin-1 supplement block and C0/C1 control codes).
    • binary: alias for 'latin1'.
    • hex: encode each byte as two hexadecimal characters.
  • crc <Boolean> Cyclic redundancy check. For code93, std25, int25 and msi barcode types. Default: true
  • rectangular <Boolean> For datamatrix only. Default: false
  • padding <Number> The space in pixels around one side of the barcode that will be applied for its 4 sides. Default: 0
  • width <Number> The width in pixels to fix for the generated image. Default: 150
  • height <Number> The height in pixels to fix for the generated image. Default: 150
  • barWidth <Number> The bar width in pixels for 1D barcodes. Default: 1
  • barHeight <Number> The bar height in pixels for 1D barcodes. Default: 50
  • original1DSize <Boolean> If true keep the original 1D barcode size determined by barWidth and barHeight else apply the specified width and height sizes to the final image. Default: false
  • original2DSize <Boolean> For rectangular datamatrixes, if true keep the original 2D barcode size based on width else apply the specified width and height sizes to the final image. Default: false
  • addQuietZone <Boolean> Add a quiet zone at the end of 1D barcodes. Default: true
  • color <String> The bars and hri color. An hexadecimal value or one of these generic names. Default: #000000
  • opacity <Number> The bars and hri opacity. Min: 0 Max: 1 Default: 1
  • bgColor <String> The background color. An hexadecimal value or one of these generic names. Default: #FFFFFF
  • bgOpacity <Number> The background opacity. Min: 0 Max: 1 Default: 1
  • hri <Object> The human readable interpretation of the encoded data.
    • show <Boolean> Default: true
    • fontFamily <String> A generic font name based on cssfontstack.com Default: Arial
      • Sans-serif
      • Arial
      • Arial Black
      • Arial Narrow
      • Arial Rounded MT Bold
      • Avant Garde
      • Calibri
      • Candara
      • Century Gothic
      • Franklin Gothic Medium
      • Futura
      • Geneva
      • Gill Sans
      • Helvetica
      • Impact
      • Lucida Grande
      • Optima
      • Segoe UI
      • Tahoma
      • Trebuchet MS
      • Verdana
      • Serif
      • Bodoni MT
      • Book Antiqua
      • Calisto MT
      • Cambria
      • Didot
      • Garamond
      • Goudy Old Style
      • Lucida Bright
      • Palatino
      • Perpetua
      • Rockwell
      • Rockwell Extra Bold
      • Baskerville
      • Times New Roman
      • Consolas
      • Courier New
      • Lucida Console
      • Lucida Sans Typewriter
      • Monaco
      • Andale Mono
      • Copperlate
      • Papyrus
      • Brush Script MT
    • fontSize <Number> The font size in pixels. Default: 10
    • marginTop <Number> The margin size in pixels between the barcode bottom and the hri text. Default: 0

• Returns: <Promise>

  • Resolve: <Object>
    • width <Number> The final image width.
    • height <Number> The final image height.
    • density <Number> The number of pixels per inch (DPI) calculated as optimized.
    • type <String> The symbology used.
    • data <String> The data encoded.
    • hri <String> The human readable interpretation of the encoded data.
    • output <String> The effective output option used.
    • encoding <String> The encoding format used.
    • svg <Readable> | <String> | <Buffer> The SVG tags of the generated SVG image. In case the ouput is a file, this field contains the SVG tags in a string format.
  • Throws: <DataError> | <BarcodeTypeError> | <OutputError>

Examples

You can find these examples here: docs/examples

In these examples please prefer a well-known and tested asynchronous logger over the use of console module.

1D barcode

const bitgener = require('bitgener');

(async () => {
  try {
    const ret = await bitgener({
      data: '012345',
      type: 'code93',
      output: 'buffer',
      encoding: 'utf8',
      crc: false,
      padding: 25,
      barWidth: 5,
      barHeight: 150,
      original1DSize: true,
      addQuietZone: true,
      color: '#FFFFFF',
      opacity: 1,
      bgColor: '#F7931A',
      bgOpacity: 0.1,
      hri: {
        show: true,
        fontFamily: 'Futura',
        fontSize: 25,
        marginTop: 9,
      },
    });

    console.log(ret);
  } catch (e) {
    console.error(e.toString());
  }
})();

2D barcode

const bitgener = require('bitgener');

(async () => {
  try {
    const ret = await bitgener({
      data: 'Bitgener',
      type: 'datamatrix',
      output: 'bitgener.svg',
      encoding: 'utf8',
      rectangular: true,
      padding: 0,
      width: 250,
      height: 250,
      original2DSize: false,
      color: '#FFFFFF',
      opacity: 1,
      bgColor: '#F7931A',
      bgOpacity: 1,
      hri: {
        show: true,
        fontFamily: 'Courier New',
        fontSize: 15,
        marginTop: 0,
      },
    });

    console.log(ret);
  } catch (e) {
    console.error(e.toString());
  }
})();

Full example using Sharp

const stream = require('stream');
const { createWriteStream } = require('fs');
const path = require('path');
const { promisify } = require('util');
const sharp = require('sharp');
const bitgener = require('bitgener');

const pipeline = promisify(stream.pipeline);

/**
 * Generic function to convert the SVG generated from Bitgener
 * into the specified format and get the specified output.
 *
 * Please note that no type/value checks are made in this function.
 *
 * @param  {Buffer} buffer    The buffer generated by Bitgener.
 * @param  {Number} density   The density needed to resize the image with no
 *                            image quality loss.
 * @param  {String} format    Format could be one of png, jpeg,
 *                            webp, tiff, raw supported by Sharp.
 * @param  {String} method    Method could be one of toFile, toBuffer,
 *                            or a Readable Stream returned by default by Sharp.
 * @param  {String} filePath  Path to write the image data to. If set, method is not required.
 * @return {Promise}          A Readable Stream by default, a Buffer,
 *                            a Sharp info object depending on the method.
 */
const convert = async function convert({
  buffer,
  density,
  format,
  method,
  filePath,
} = {}) {
  // sharp it!
  const sharped = sharp(buffer, { density });
  let ret;

  if (method === 'toFile' || filePath !== undefined) {
    ret = await sharped.toFile(filePath);
    // object returned by sharp: https://sharp.pixelplumbing.com/en/stable/api-output/#tofile
  } else if (method === 'toBuffer') {
    ret = sharped.toFormat(format).toBuffer();
  } else {
    // return a sharp/streamable object
    ret = sharped[format]();
  }

  return ret;
};

// then use it in an async function
(async () => {
  try {
    const wstream = createWriteStream(path.join(__dirname, 'sharped.png'));
    const {
      svg: buffer,
      density,
    } = await bitgener({
      data: 'Bitgener',
      type: 'datamatrix',
      output: 'buffer',
      encoding: 'utf8',
      rectangular: true,
      padding: 0,
      width: 250,
      height: 250,
      original2DSize: false,
      color: '#FFFFFF',
      opacity: 1,
      bgColor: '#F7931A',
      bgOpacity: 1,
      hri: {
        show: true,
        fontFamily: 'Courier New',
        fontSize: 15,
        marginTop: 0,
      },
    });

    const rstream = await convert({
      buffer,
      density,
      format: 'png',
    });

    // listen to rstream and wstream error events ;)

    // use pipeline to automatically clean up streams or you're exposing your code to memory leaks
    await pipeline(rstream, wstream);

    // ...
  } catch (e) {
    console.error(e.toString());
  }
})();

Environment variables

DEBUG is used to whether debug a specific module. DEBUG value can be a comma-separated string listing module names to debug or to avoid debugging. Format is: DEBUG=moduleName[,moduleName]

• DEBUG=moduleName will debug moduleName module;
• DEBUG=moduleName:* will debug moduleName module and sub modules;
• DEBUG=-moduleName:* will disable debugging any moduleName module and sub modules;
• DEBUG=* will debug all moduleName module and sub modules plus other modules used in your project if they use a debugger similar to bugbug embed in this module.

Example: DEBUG=bitgener:*

Errors

Object structure

Errors emitted by Bitgener inherit the native Error prototype with an additional code property and toString method.

{
  name,
  code,
  message,
  stack,
  toString(),
}

Codes

Code of Conduct

This project has a Code of Conduct. By interacting with this repository, organization, or community you agree to abide by its terms.

Contributing

Please have a look at our TODO for any work in progress.

Please take also a moment to read our Contributing Guidelines if you haven't yet done so.

Support

Please see our Support page if you have any questions or for any help needed.

Security

For any security concerns or issues, please visit our Security Policy page.

License

MIT.