Simple Pixel Middleware

pixel_writer.rb

module CBVisitorTracker
  module MiddleWare
      class PixelWriter
      def initialize(appl)
        @app = appl
      end
      def call(env)
        response= @app.call(env)
        status,headers,body= response
        headers['Content-Length']= body.length.to_s
        return [status,headers,body] if headers["Content-Type"] !~ /text\/html|application\/xhtml\+xml/

        imagetag = %Q!<img src='http://localhost:8081/track/?event=wat' />!
        resp = Rack::Response.new 
        index = body.body.first.rindex("</body>")
        body.body.first.insert index, imagetag 
        resp.body = body.body
        resp.status = status
        resp.finish

        # This works defaulty below
        # [status,headers,body]
      end
      end
  end
end