UPDATE: A new pre-release has been made v1.0.0.pre. A fresh start after a long pause. There is actually no new functionality in the release but there are some dependency changes. Minimum Ruby version is now ~> 2.3. This release also cleans up the internals a bit. The core QR Code generation has been extracted into a new rqrcode_core gem. This enables qrqcode to concentrate on rendering. Once v1.0.0.pre has had time for people to try I'll release v1.0.0 of rqrcode and then concentrate on working through issues and PRs although I appreciate many of these may be old and out of date now! You can install this pre-release with gem install rqrcode --pre or gem 'rqrcode', '>= 1.0.0.pre' in your Gemfile.

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
• 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
)

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(
  resize_gte_to: false,
  resize_exactly_to: false,
  fill: 'white',
  color: 'black',
  size: 120,
  border_modules: 4,
  module_px_size: 6,
  file: nil # path to write
)

IO.write("/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

Contributing

• 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)