em example

gistfile1.txt

    activity = self
    EventMachine.run do
      operation = proc {
        if activity.new_contents.any?
          sc = nil
          while sc.nil?
            sc = SiteContent.find(activity[:scontent_ids].first) rescue nil
            sleep(0.1)
          end
          sc
        else
          SiteContent.find(activity[:scontent_ids].first) rescue nil
        end
      }
      callback = proc { |sc|
        puts sc.try(:as_json_cairo, {:fields => [:all]}) rescue nil
        EventMachine.stop
      }
      EventMachine.defer(operation, callback)
    end