RQRCode

RQRCode is a library for creating and rendering QR codes into various formats. It has a simple interface with all the standard QR code options. It was adapted from the Javascript library by Kazuhiko Arase.

• QR code is trademarked by Denso Wave inc
• Minimum Ruby version is >= 2.3
• For rqrcode releases < 1.0.0 please use this README

Installing

Add this line to your application's Gemfile:

gem 'rqrcode'

or install manually:

gem install rqrcode

Basic usage example

require 'rqrcode'

qr = RQRCode::QRCode.new('http://github.com')
result = ''

qr.qrcode.modules.each do |row|
  row.each do |col|
    result << (col ? 'X' : 'O')
  end

  result << "\n"
end

puts result

Advanced Options

These are the various QR Code generation options provided by rqrqcode_core.

string - the string you wish to encode

size   - the size of the qrcode (default 4)

level  - the error correction level, can be:
  * Level :l 7%  of code can be restored
  * Level :m 15% of code can be restored
  * Level :q 25% of code can be restored
  * Level :h 30% of code can be restored (default :h)

mode   - the mode of the qrcode (defaults to alphanumeric or byte_8bit, depending on the input data):
  * :number
  * :alphanumeric
  * :byte_8bit
  * :kanji

Example

qrcode = RQRCodeCore::QRCode.new('hello world', size: 1, level: :m, mode: :alphanumeric)

Render types

You can output your QR code in various forms. These are detailed below:

as SVG

The SVG renderer will produce a stand-alone SVG as a String

require 'rqrcode'

qrcode = RQRCode::QRCode.new("http://github.com/")

# NOTE: showing with default options specified explicitly
svg = qrcode.as_svg(
  offset: 0,
  color: '000',
  shape_rendering: 'crispEdges',
  module_size: 6,
  standalone: true
)

as ANSI

The ANSI renderer will produce as a string with ANSI color codes.

require 'rqrcode'

qrcode = RQRCode::QRCode.new("http://github.com/")

# NOTE: showing with default options specified explicitly
svg = qrcode.as_ansi(
  light: "\033[47m", dark: "\033[40m",
  fill_character: '  ',
  quiet_zone_size: 4
)

as PNG

The library can produce a PNG. Result will be a ChunkyPNG::Image instance.

require 'rqrcode'

qrcode = RQRCode::QRCode.new("http://github.com/")

# NOTE: showing with default options specified explicitly
png = qrcode.as_png(
  bit_depth: 1,
  border_modules: 4,
  color_mode: ChunkyPNG::COLOR_GRAYSCALE,
  color: 'black',
  file: nil,
  fill: 'white',
  module_px_size: 6,
  resize_exactly_to: false,
  resize_gte_to: false,
  size: 120
)

IO.binwrite("/tmp/github-qrcode.png", png.to_s)

On the console ( just because you can )

require 'rqrcode'

qr = RQRCode::QRCode.new('http://kyan.com', size: 4, level: :h)

puts qr.to_s

Output:

xxxxxxx   x x  xxx    xxxxxxx
x     x  xxxxx  x x   x     x
x xxx x    x x     x  x xxx x
x xxx x  xxx  x xxx   x xxx x
x xxx x xxx  x  x  x  x xxx x
... etc

API Documentation

http://www.rubydoc.info/gems/rqrcode

Tests

You can run the test suite using:

$ ./bin/setup
$ bundle exec rspec

or try the lib from the console with:

$ ./bin/console

Contributing

The current as_png, as_css, as_svg, as_ansi etc etc renderings of a QR Code will eventually (when I can get round to it) be moved into their own gems so they can be managed independently by people in their own repos -- ideally -- who are interested in this kind of thing. This will leave me to look after rqrcode_core gem which I do have time for.

So for example if you only required a png rendering of a QR Code, you could simply use the gem rqrcode_png. This eventually means that the rqrcode gem will just become a lightweight gem that pulls in all the various rendering and TBH will likely be depreciated.

The motivation behind all this is because the rendering side of this gem takes up the most time. Everyone wants a slightly different version of a QR Code and it's impossible to support everyone. The easiest way is to empower people to create their own which they can manage.

The work shouldn't impact any current users of the gem. What this does mean though is that any contribution PR's should only be bug fixes rather than new functionality. Thanks.

• Fork the project
• Send a pull request
• Don't touch the .gemspec, I'll do that when I release a new version

Authors

Original RQRCode author: Duncan Robertson

A massive thanks to all the contributors of the library over the years. It wouldn't exist if it wasn't for you all.

Oh, and thanks to my bosses at https://kyan.com for giving me time to maintain this project.

Resources

• wikipedia:: http://en.wikipedia.org/wiki/QR_Code
• Denso-Wave website:: http://www.denso-wave.com/qrcode/index-e.html
• kaywa:: http://qrcode.kaywa.com

Copyright

MIT License (http://www.opensource.org/licenses/mit-license.html)