Building the Realtime User Experience

Sending Instant Messages

Receiving messages that originated from an instant messenger client is nice to have, and certainly opens up a lot of possibilities for collecting data in realtime. But the true realtime power of this technology comes from the ability to both send and receive these messages.

Let’s expand on our existing application by taking the message that we received and just printing it back to the client. In the main.py file, make the following addition to the XMPPHandler class:

class XMPPHandler(BaseHandler):
    def post(self):
        # Parse the XMPP request
        message = xmpp.Message(self.request.POST)
         # Log it to the console
        logging.info("XMMP sender: %s - body: %s" % (message.sender, message.body))
        message.reply(message.body)

That additional line of code takes the message that was received and calls the reply method to send the body right back to the sender. If you’d like to test this out on the server, go ahead and deploy the code as it is now. Figure 7-12 shows a typical chat session with the server after adding this functionality.

Figure 7-11. The lifetime of the instant message

Figure 7-12. Chatting with myself via the server