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rqrcode

A Ruby library that encodes QR Codes

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.

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
)

QR code with github url

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
)

QR code with github url

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)

QR code with github url

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

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

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