Question

Do any one knows how to implement file sending via http from client to client. This is similar example but can not find how to implement it: http://jetbytes.com/
Any ideas?

Answer 1

Guess you could just copy their behaviour, which is roughly the following.

Let’s name the three parts of the exchange : Sender (in a browser), Server (well… server code), Receiver (in a browser).

• Sender UI: the user selects a file ;
• Sender: periodically (every second here), update the server saying that Sender is ready to send the file. While the Server is not ready, it just answers “I am not ready” to the Sender ;
• Receiver GETs the generated URL ;
• Sender (as before) updates the server saying that it is ready to send the file. This time the server answers “I am ready” ;
• Sender simply POST the file (as it would do in the most simple HTML form).
  • The Server relays the POST data to the Receiver (with relevant headers) ;
  • This operation takes time, so the following operations are just meant to update the progress bar Sender-side.
• Sender asks periodically (every second here) how much data the Server got so far ; the Server answers how much it has received and how much it expects until the end.
• Sender updates its progress bar.
• …
• Sender asks how much data the Server got so far ; the Server answers it is done.
• Closing routines on three parts of the exchange.

Of course there must be room for improvement :

• Periodic updates could be replaced by another technology (see http://en.wikipedia.org/wiki/Push_technology) ;
• If the transfer is interrupted before it finishes, make it possible to continue where the transfer got interrupted ;
• …many other aspects

For the implementation, much of the work will be on the client side, and everything described here is achievable using jQuery. On the server, the two goals are transferring data and answering to the Sender. You will have to define yourself a lightweight protocol to say “I am [not] ready”, “I got N bytes so far”, “I am done”.