Requirements

• Django_
• Tornado_

.. _Django: http://www.djangoproject.com/ .. _Tornado: http://www.tornadoweb.org/

Instructions

1. cd myproject
2. python manage.py runtornado --reload 8000
3. Go to: http://localhost:8000/

Now you have a working chat server -- this is based on the NodeJS chat server, UI primarily.

Quick Tutorial

Django request/response is untouched. To utilize Tornado's async capabilities, a decorator is avilable. Which adds an extra argument to your request handler, which is the Tornado handler class -- all functions are available.

If you return a value it is assumed to be a Django Response, if nothing is returned then it is assumed that you're doing async response processing.

from django_tornado.decorator import asynchronous

@asynchronous
def recv(request, handler) :
    response = {}

    if 'since' not in request.GET :
        return ChatResponseError('Must supply since parameter')
    if 'id' not in request.GET :
        return ChatResponseError('Must supply id parameter')

    id = request.GET['id']
    session = Session.get(id)
    if session :
        session.poke()

    since = int(request.GET['since'])

    def on_new_messages(messages) :
        if handler.request.connection.stream.closed():
            return
        handler.finish({ 'messages': messages, 'rss' : channel.size() })

    channel.query(handler.async_callback(on_new_messages), since)

Advanced Usage

Since Tornado is a single threaded server which blocks on long operations (e.g. slow DB queries) it''s useful to run multiple servers at the same time. That''s now supported on the command line, for

 python manage.py runtornado 8000 8001 8002 8003

Which enables the following nginx configuration (skipping lots of details)

upstream frontends {
    server 127.0.0.1:8000;
    server 127.0.0.1:8001;
    server 127.0.0.1:8002;
    server 127.0.0.1:8003;
}

...

location / {
    proxy_pass http://frontends;
}

Acknowledgements

Idea and code snippets borrowed from http://geekscrap.com/2010/02/integrate-tornado-in-django/ Chat server http://github.com/ry/node_chat