WebSockets ?

• HTTP request/response Paradigm
• Persistent connection need:
  • AJAX (2005), long polling
• WebSockets: RFC 6455 (dec. 2011)

Django & WSGI

The solution?

django-channels

• Official Django project (Andrew Godwin, Sept. 2016)
• Provide an alternative to WSGI: ASGI

Simple example

Django setup

Project setup

• Model Message (subject, body)
• ./manage.py makemigrations/migrate
• message list (simple url, view and template)

WebSockets setup

Bonus

More features

• Redis channel layer
• Group (e.g. chat groups)
• Friendly decorators :
  • Access session
  • Enforce ordering

That's all folks!

Here are some resources:

• http://stackoverflow.com/questions/11077857/what-are-long-polling-websockets-server-sent-events-sse-and-comet

• https://www.html5rocks.com/en/tutorials/websockets/basics/

• http://sametmax.com/quest-ce-que-wsgi-et-a-quoi-ca-sert/

• https://tools.ietf.org/html/rfc6455
• https://www.djangoproject.com/weblog/2016/sep/09/channels-adopted-official-django-project/
• http://natim.github.io/django-slides/channels/
• https://channels.readthedocs.io