Overview:

django-pubsub allows you to create Twitter like real-time updates for your models.

PubSub is a way to publish and subscribe to events over XMPP. Instead of intensive polling, it relies on the publisher pushing the information and the client subscribing and receiving the events.

django-pubsub makes use of the XMPP pubsub implementation (refer to XEP 0060 for details).

You will need:

1. An XMPP server with pubsub support (tested with ejabberd)
2. A BOSH transport to XMPP (tested with nginx and ejabberd)
3. xmpppy
4. Strophe.js and pubsub plugin

Usage:

Publish:

You have "Tweet" model in your models and you want to make the updates real-time.

Just do:

from pubsub import pubsub

pubsub.register(Tweet)

You can register multiple models by passing them in a list. Each registered model becomes a Publisher Node and will notify all subscribers about any new instances created. The node created is named after the app and the model. If your app is named Twitter, your node for Tweet model would be /Twitter/Tweet. The payload passed along with the notification includes the instance serialized to XML.

You can also publish events to nodes anywhere in your view with:

from pubsub import publish
publish("/home", "Hello World")

Subscribe:

A XMPP client written in strophe.js will listen to the Publisher and receive events. The app includes a client in media/js.

To use the client you need to include:

<script type="text/javascript" src="{{ MEDIA_URL }}/js/jquery-1.4.2.min.js"></script>
<script type="text/javascript" src="{{ MEDIA_URL }}/js/strophe.js"></script>
<script type="text/javascript" src="{{ MEDIA_URL }}/js/strophe.pubsub.js"></script>
<script type="text/javascript" src="{{ MEDIA_URL }}/js/pubsub.settings.js"></script>
<script type="text/javascript" src="{{ MEDIA_URL }}/js/pubsub.client.js"></script>

in your template.

Invoke the client using:

pubsub = new PubSubClient({
        'nick': <unique_nick>,
        'node': '<node>',
        'event_cb': <callback to receive the events>
});

or if you need authorized user to login, pass username and password instead of nick

A simple event callback would be:

function event_cb(entry, pubsub) {
    console.log("payload: ", $(entry).text());
    console.log("unread: ", pubsub.unread);
}

The callback event_cb receives new updates. entry consists of the payload sent by the publisher enclosed in a <entry> tag. pubsub is the instance of PubSubClient.

In addition you also have access to pubsub.unread which is the number of hits when the window was not in focus, and pubsub.focus which is true if the window is active else false

django-pubsub is web scale