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https://github.com/niwinz/django-sse

HTML5 Server-Sent Events integration for Django
https://github.com/niwinz/django-sse

Last synced: 13 days ago
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HTML5 Server-Sent Events integration for Django

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README 

        
==========

django-sse

==========



**Warning**: this package is now unmantained because django is not the optimal platform for persistent connections.

I strongly recommend use anything like tornado or asyncio with python3 for this purpose.



Django integration with Server-Sent Events. (http://www.html5rocks.com/en/tutorials/eventsource/basics/)

(https://developer.mozilla.org/es/docs/Server-sent_events/utilizando_server_sent_events_sse)



This django application uses the module sse_, simple python implementation of sse protocol.



Introduction

------------



Is very similar to Django's generic views.



``django-sse`` exposes a generic view for implement the custom logic of the data stream.

Additionally, it  exposes some helper views for simple enqueuing messages for a client,

using redis or rabbitmq(not implemented).



**NOTE**: it strongly recomended expose this views with gevent pywsgi server, because every connection is

permanent blocking stream.



Implementing own view with sample stream

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~



The idea is to create a stream of data to send the current timestamp every 1 second to the client:



.. code-block:: python



    from django_sse.views import BaseSseView

    import time



    class MySseStreamView(BaseSseView):

        def iterator(self):

            while True:

                self.sse.add_message("time", str(time.time()))

                yield

                time.sleep(1)



The ``iterator()`` method must be a generator of data stream. The view has ``sse`` object,

for more information, see sse_ module documentation.



The acomulated data on sse is flushed to the client every iteration (yield statement).

You can flush the buffer, sometimes as you need.



Using a redis as message queue for push messages to client

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~



``django-sse`` currently implements a redis helper for simple enqueuing messages for push to a clients.

For use it, the first step is a url declaration:



.. code-block:: python



    from django.conf.urls import patterns, include, url

    from django_sse.redisqueue import RedisQueueView



    urlpatterns = patterns('',

        url(r'^stream1/$', RedisQueueView.as_view(redis_channel="foo"), name="stream1"),

    )



This, on new connection is created, opens connection to redis and subscribe to a channel. On

new messages received from redis, it flushes theese to client.



And the second step, your can push messages to the queue in any other normal django views

with a simple api:



.. code-block:: python



    from django.http import HttpResponse

    from django_sse.redisqueue import send_event



    def someview(request):

        send_event("myevent", "mydata", channel="foo")

        return HttpResponse("dummy response")



``RedisQueueView`` precises of redis, put your connection params on your ``settings.py``:



.. code-block:: python



    REDIS_SSEQUEUE_CONNECTION_SETTINGS = {

        'location': 'localhost:6379',

        'db': 0,

    }



Can subscribe to a channel dynamically with some parameter on url?

------------------------------------------------------------------



Yes, you need create a subclass of ``RedisQueueView`` and overwrite the method ``get_redis_channel``.

Example:



.. code-block:: python



    # urls.py

    urlpatterns = patterns('',

        url(r'^sse/(?P\w+)/$', MyRedisQueueView.as_view(redis_channel="foo"), name="stream1"),

    )



    class MyRedisQueueView(RedisQueueView):

        def get_redis_channel(self):

            return self.kwargs['channel'] or self.redis_channel



Contributors:

-------------



* Flavio Curella / https://github.com/fcurella



License

-------



BSD License



.. _sse: https://github.com/niwibe/sse