Django SSE Wrapper

Django SSE wrapper is an easy way to implement Server-Sent Events in a Django application. You can find details about SSE at http://www.html5rocks.com/en/tutorials/eventsource/basics/

Installation

Installing from PyPI:

$ pip install django-sse-wrapper

Usage

Django SSE Wrapper exposes a view called EventStreamView that implements the SSE logic. In your urls.py you will specify a pattern like:

from django.conf.urls import patterns, url

from sse_wrapper.views import EventStreamView


urlpatterns = patterns(
    '',
    url(r'^an-event-stream/$',
        EventStreamView.as_view(channel='some-channel-name'),
        name='an_event_stream'),
)

You can also specify a channel extension. This may be useful, for example, when you have an event stream called course_state_stream, but that needs to differ from one course to another (by course_id, for example). The url pattern would look like:

from django.conf.urls import patterns, url

from sse_wrapper.views import EventStreamView


urlpatterns = patterns(
    '',
    url(r'^course-state-stream/(?P<channel_extension>[\w]+)/$',
        EventStreamView.as_view(channel='course-state'),
        name='course_state_stream'),
)

Brokers

For now, I only support two backend brokers: Memory (testing purpose only) and Redis. Soon I'll be adding support to RabbitMQ, ZeroMQ, and others.

In your settings.py you must specify the broker and its properties:

SSE_BACKEND_CLASS = 'sse_wrapper.backends.redis_based.RedisBasedBackend'
SSE_BACKEND_CONNECTION_SETTINGS = {
    'host': 'localhost',
    'port': 6379,
    'db': 0,
}

Production Environment Notes

Because Server-Sent Events are streams of data, they require long-lived connections. You’ll want to use a server can handle large numbers of simultaneous connections. I strongly recomend you to use some gevent WSGI server.

Contributing

Install Vagrant in order to run the example app and test the code.

License

BSD License

Note: this project is based on django-sse written by niwibe. The reason I started a new project instead of forking is that I decided to change the whole design of the code. I like the idea of omitting the broker from the app code, this way when you decide to change from one broker to another, you just have to change your settings.py.