rQRCode, Encode QRCodes

Short changelog

0.8.0 (Dec 18, 2015)

• Added numeric QR code support
• Dropped Ruby v1.8 support

0.7.0 (Aug 15, 2015)

• Added shape_rendering option for as_svg

0.6.0 (Jun 2, 2015)

• Improved png rendering. Previous png rendering could result in hard to scan qrcodes. Big thanks to Bart Jedrocha

0.5.5 (Apr 25, 2015)

• Fixed major bug. The rs block data was missing resulting in qr codes failing to be generated. Upgrade highly recomended!!

Overview

rQRCode is a library for encoding QR Codes in Ruby. It has a simple interface with all the standard qrcode options. It was adapted from the Javascript library by Kazuhiko Arase.

Let's clear up some rQRCode stuff.

• rQRCode is a ruby only library It requires no native libraries. Just Ruby!
• It is an encoding library. You can't decode QR codes with it.
• The interface is simple and assumes you just want to encode a string into a QR code
• QR code is trademarked by Denso Wave inc

Installing

You may get the latest stable version from Rubygems.

gem install rqrcode

Using rQRCode

require 'rqrcode'

qrcode = RQRCode::QRCode.new("http://github.com/")
image = qrcode.as_png
svg = qrcode.as_svg
html = qrcode.as_html
string = qrcode.to_s

Image Rendering

SVG

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

qrcode = RQRCode::QRCode.new("http://github.com/")
# With default options specified explicitly
svg = qrcode.as_svg(offset: 0, color: '000', 
                    shape_rendering: 'crispEdges', 
                    module_size: 11)

PNG

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

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

HTML Rendering

In your controller

@qr = RQRCode::QRCode.new( 'https://github.com/whomwah/rqrcode', :size => 4, :level => :h )

In your view

<%= raw @qr.as_html %>

CSS

table {
  border-width: 0;
  border-style: none;
  border-color: #0000ff;
  border-collapse: collapse;
}

td {
  border-left: solid 10px #000;
  padding: 0; 
  margin: 0; 
  width: 0px; 
  height: 10px; 
}

td.black { border-color: #000; }
td.white { border-color: #fff; }

On the console

qr = RQRCode::QRCode.new( 'my string to generate', :size => 4, :level => :h )
puts qr.to_s

Output:

xxxxxxx x  x x   x x  xx  xxxxxxx
x     x  xxx  xxxxxx xxx  x     x
x xxx x  xxxxx x       xx x xxx x
... etc 

Doing your own rendering

qr = RQRCode::QRCode.new( 'my string to generate', :size => 4, :level => :h )
qr.modules.each do |row|
    row.each do |col| 
        print col ? "X" : " "
    end
    print "\n"
end

Specifying QR code mode

Sometimes you may want to specify the QR code mode explicitly.

It is done via the mode option. Allowed values are: number, alphanumeric and byte_8bit.

qr = RQRCode::QRCode.new( '1234567890', :size => 2, :level => :m, :mode => :number )

API Documentation

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

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

Authors

Original author: Duncan Robertson

Special thanks to the following people for submitting patches:

• Chris Mowforth
• Daniel Schierbeck
• Gioele Barabucci
• Ken Collins
• Rob la Lau
• Tore Darell
• Vladislav Gorodetskiy

Contributing

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

Copyright

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