trustieforge/app/controllers/test_controller.rb

class TestController < ApplicationController

  def zip
    homeworks_attach_path = []
    homework_id = params[:homework_id]
    bid = Bid.find_by_id(homework_id)

    bid.homeworks.each do |homeattach|
      homeattach.attachments.each do |attach|
        homeworks_attach_path << attach.diskfile
      end
    end
    @paths = homeworks_attach_path
    zipfile = ziping homeworks_attach_path
    send_file zipfile, :filename => bid.name,
                        :type => detect_content_type(zipfile)

  end

  def courselist
    @courses = Project.course_entities
  end

  def ziping files_path
    folder = "/tmp"
    input_filename = files_path
    zipfile_name = "/tmp/archive_#{Time.now.to_i}.zip"

    Zip::File.open(zipfile_name, Zip::File::CREATE) do |zipfile|
      input_filename.each do |filename|
        zipfile.add(filename, folder + '/' + filename)
      end
      zipfile.get_ouput_stream("ReadMe"){ |os|
        os.write "myFile contains just this"
      }
    end
    zipfile_name
  end

  def detect_content_type(name)
    content_type = Redmine::MimeType.of(name)
    content_type.to_s
  end
end