rQRCode, Encode QRCodes

Short changelog

0.8.0 (Dec 8, 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 standalone library It requires no other 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:

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)

toncid/rqrcode