symbology

Symbology.js

Generate 50+ different 1D or 2D barcodes in png, eps, or svg format.

0. Contents

• 1. Introduction
• 2. Installation
• 3. Usage
  • 3.1. Import the module
  • 3.2. Struct
  • 3.3. Available functions
    • 3.3.1. Stream a barcode
    • 3.3.2. Render a file
• 4. Available options (struct)
• 5. Error handling
• 6. Symbology types
• 7. Development
  • 7.1. Building
    • 7.1.1. Prerequisites
  • 7.2. Testing
  • 7.3. Packaging
  • 7.4. Bugs
  • 7.5. Changelog
• 8. Credits
• 9. License

1. Introduction

This Node.js module will allow you to generate over 50+ different types of 1D or 2D symbologies, including barcodes for books, grocery, shipping carriers, healthcare, and international codes. It can save a png, svg, or eps image, or render a base64 png bitmap.

2. Installation

yarn add symbology

or:

npm install symbology --save

If you run into issues when building compiling the module locally, please make sure you have the prerequisites installed. For more info, see: 7.1.1. Prerequisites.

3. Usage

3.1. Import the module

var symbology = require('symbology');

3.2. Struct

Prepare a Symbol json object with your desired settings (see 4. Available options (struct) for more info):

var Symbol = {
  symbology: symbology.Barcode.CODE128,
  foregroundColor: 'fff000',
  backgroundColor: '000000',
  fileName: '/my/directory/barcode.png'
};

3.3. Available functions

Each function returns a promise that completes with an object containing the exit code and message of the function (see 5. Error handling for more info).

---

3.3.1. Stream a barcode:

createStream(Symbol, data, outputType)

Writes the file string to the output object in a property data. Returns a Promise.

Note: For png, it will render data as a base64 string.

Parameter	Type	Values	Default
Symbol	Struct	Struct of symbology settings
data	String	Desired data to encode
outputType	String	Output type	PNG

Output Types

Enum	Description
EPS	Adobe encapsulated postscript vector
SVG	Scalable vector graphics
PNG	Portable network graphics

Example

symbology
  .createStream(Symbol, '12345', symbology.Output.PNG)
  .then(function(data) {
    console.log('Result: ', data);
  }, function(err) {
    console.log('Error: ', err);
  });

Returns:

Result: {
  message: '',
  code: 0,
  data: 'data:image/png;base64,iVBOR [...] g=='
}

---

3.3.2. Render a file:

createFile(Symbol, data, type)

Creates a file with the requested barcode. Returns a Promise.

Note: The file type of the barcode to render is based on the extension fileName setting. For example, to render an svg, the fileName must be of the format: <myfile>.svg.

Parameter	Type	Values
Symbol	Struct	Struct of symbology settings
data	String	Desired data to encode

Example

symbology
  .createFile(Symbol, '12345')
  .then(function(data) {
    console.log('Result: ', data);
  }, function(err) {
    console.log('Error: ', err);
  });

This creates a file in the specified fileName and will log:

Result: {
  message: '',
  code: 0,
  fileName: 'barcode.png'
}

4. Available options (struct)

A Symbol is a regular JavaScript object with the following available properties:

Enumerated type	Type	Meaning	Required?	Default value
symbology	Symbology enum	The enumerated type of the symbology (see Enumerated Barcode Types for more info).	Yes
height	Number	The height of the image. If specified, this will maintain the aspect ratio.	No	50
whitespaceWidth	Number	Width of whitespace, for barcodes which have this option.	No	0
borderWidth	Number	Width of border.	No	0
outputOptions	Number	Symbology-specific output option.	No	NULL
foregroundColor	Hexadecimal number	Barcode foreground color.	No	FFFFFF
backgroundColor	Hexadecimal number	Barcode background color.	No	000000
fileName	String	Full path to the file to render.	Yes
scale	Number	Scale of the barcode image. Applies only to PNG.	No	1.0
option1	Number	Symbology-type-specific option value.	No	NULL
option2	Number	Symbology-type-specific option value.	No	NULL
option3	Number	Symbology-type-specific option value.	No	NULL
showHumanReadableText	Boolean	Show or hide the symbology data as human-readable text (if applicable).	No	true

* required only if using createFile().

5. Error handling

Each function returns an object having property code, which is the status code of the function, and message, which contains an error/warning message (if any).

Below are the possible status codes:

Code	Enumerated type	Meaning
2	ZWARN_INVALID_OPTION	One or more options are invalid but the barcode was created anyway.
5	ZERROR_TOO_LONG	The file path was too long.
6	ZERROR_INVALID_DATA	The data for the specified symbology is invalid.
7	ZERROR_INVALID_CHECK	Error checking (if any) on the rendered barcode failed.
8	ZERROR_INVALID_OPTION	One or more options are invalid and rendering failed.
9	ZERROR_ENCODING_PROBLEM	Invalid characters in input data.
10	ZERROR_FILE_ACCESS	Cannot write to the given path.
11	ZERROR_MEMORY	Corrupt or insufficient memory.

6. Symbology types

There are 53 different available symbology types. For an exhaustive list, please see the Barcode Types list.

7. Development

7.1. Building

yarn build

7.1.1. Prerequisites

libpng is a required for building this module. If you receive an error that png.h was not found, it is because libpng is not installed locally.

7.2. Testing

yarn test

7.3. Packaging

yarn package-binary

7.4. Bugs

Please report any bugs here.

7.5. Changelog

Available here.

8. Credits

This library is a JS/C++ wrapper module for the terrific C/C++ library Zint, (C) Robin Stuart. Module by Josh Shor.

9. License

MIT.

Changelog

2.0.0 (2021-03-29)

Bug Fixes

• adds patch system to apply stdout fixes (d0ac5bc)
• adds support for Node v12+ (bffc800)
• appveyor: update script to include debug msg and wrap conditionals (#26) (2859265)
• binding: updates lib to properly convert bitmap chars (51c0990)
• powershell bug (#27) (c8e6fdf)
• unix: removes remaining png.c refs; enables pipe() for non-Win32 (7131d1c)
• version: adds missing C file ref, version mgmt (#37) (0903303)

Features

• alpha: implements alpha channel support #35 (993699b)
• encoding: adds encoding support for ECI and input modes (#30) (e9ff0d0)
• implements ability to alter dot size #32 (32b9b42)
• rotation: implements rotations #31 (11b69e6)
• windows: adds Node 11+ support (#23) (915f15c)
• zint: upgrades to v2.9.1 (3bd4855)

BREAKING CHANGES

• zint: drops support for Node 10 and 11.