Crystal Lang QR Code

Native crystal lang QR code, no external dependencies

Installation

Add the dependency to your shard.yml:

dependencies:
  qr-code:
    github: spider-gazelle/qr-code

Run shards install

Uasge

require "qr-code"

qr = 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

require "qr-code"

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

  print "\n"
end

Rendering an SVG

require "qr-code"

svg_string = QRCode.new("my string to generate").as_svg

Credits

Based off the ruby gem: https://github.com/whomwah/rqrcode_core Which was adapted from the javascript library: https://github.com/kazuhikoarase/qrcode-generator