delete the file from the server after the download is completed

Question

I have a file server which has to be deleted after a user downloads it. I send the file with send_file, but I can't just put a File.delete(path) after that line because send_file returns immediatly, so the file is deleted even before the user receives the complete file.

How do I fix this? I think it's a common problem but haven't found a solution yet.

Here is my code below:

def export_rawdata
  @device = Device.find_by_id( params[:id] )
  @messages = @device.devmessages.all( :order => "id", :conditions => ["packettime >= ? and packettime <= ?", params[:start_time], params[:end_time]] )
  raw_data_path = "#{Rails.root}/tmp/exports/#{@device.s_dev_name}.csv"
  FasterCSV.open(raw_data_path, "w+") do |csv|
    csv << ["Packet","Created At"]
    @messages.each_with_index do |m,i|
     x = m.created_at
     csv << [m.message, x.strftime('%h %d, %G %r')]
    end
  end

  send_file raw_data_path, :type => "text/csv", :x_sendfile => true, :streaming => false

end

Can Anyone please suggest me, how to delete a file from the server once the download is completed in the client side?

check http://stackoverflow.com/questions/18232088/in-ruby-on-rails-after-send-file-method-delete-the-file-from-server — Nithin, Nov 28 '14 at 09:49

score 1 · Answer 1 · answered Dec 16 '11 at 06:38

I have read (once more) the section in the "Rails Guides for Controller, Section sending files". You have chosen the options so your method returns immediately, so there is no chance to get the information that the download has completed. Depending on the network and the client behavior, you will never know if the file download was completed.

So you could think about a workaround (no real code, only the idea):

If you know how long the download may need, define the interval (in minutes) that is at least needed.
Store your temporary files in folders that are segmented by time.
Create new folders for new segments, when the time has come.
From time to time, delete old folders (segments older than x * delta minutes) and delete the whole folder.

By that technique, depending on the usage, you will have a constant overhead for older temporary files.

can u suggest me how the apache2 server know when the file download is completed? have u used xsendfiletemporary in virtual host of apache2 — shonali, Dec 29 '11 at 13:20

delete the file from the server after the download is completed

1 Answers1