rucaptcha/app/controllers/ru_captcha/captcha_controller.rb

module RuCaptcha
  class CaptchaController < ActionController::Base
    def index
      return head :ok if request.head?
      headers['Cache-Control'] = 'no-cache, no-store, max-age=0, must-revalidate'
      headers['Pragma'] = 'no-cache'
      if params[:format] == "wav" and RuCaptcha.espeak?
        data = generate_speech_rucaptcha
        opts = { disposition: 'inline', type: 'audio/wav' }
      else
        data = generate_rucaptcha
        opts = { disposition: 'inline', type: 'image/gif' }
      end
      send_data data, opts
    end
  end
end