Read Barcodes with a Dragonfly Analyzer

barcode_analyzer.rb

class BarcodeAnalyser
  def call(app, opts = {})
    # OS X: `brew install zbar`
    # Ubuntu: `apt-get install zbar-tools`
    app.env[:zbar_command] = opts[:zbar_command] || 'zbarimg'

    app.define :barcode do
      @barcode ||= begin
        shell_eval { |path| "#{app.env[:zbar_command]} -q --raw #{path}" }
      rescue Dragonfly::Shell::CommandFailed => e
        Dragonfly.debug(e)
        nil
      end
    end
  end
end

dragonfly.rb

require 'dragonfly'
require 'barcode_analyzer'

Dragonfly.app.configure do
  plugin BarcodeAnalyser.new
end