django-eventhandler 0.3.3

Installation and configuration

Install the application in your Django project. Add ‘eventhandler’ to your INSTALLED_APPS setting. Then, add the following two settings to your project settings file.

LISTENER_URL = 'amqps://<user>:<pass>@<hostname>/<vhost>'
LISTENER_QUEUE = 'my-application'

Optionally, you can also specify these three settings, to have an exchange declared.

LISTENER_EXCHANGE = 'events'
LISTENER_EXCHANGE_TYPE = 'topic'
LISTENER_ROUTING_KEY = '#'

Running the event handler

Manually: python manage.py event_listener. To daemonize it, you can use something like supervisor to manage the process.

Usage

Events that are received from AMQP should be JSON-encoded dicts. Each message should have a key named type, with str value. This value can be used in a decorator, to have the event handler execute a function when receiving an event.

Example:

from eventhandler import handles_event

@handles_event('my_event')
def do_something_clever(event):
    pass

Now each event with a ‘type’: ‘my_event’ combo will be passed into this function. Of course it’s possible to have more than one handler for an event, or have one handler handle multiple events.

from eventhandler import handles_event

@handles_event('my_other_event')
@handles_event('my_event')
def do_something_clever(event):
    pass

@handles_event('my_other_event')
def do_something_else(event):
    pass

NB Make sure that your handlers are in a place that’s loaded/scanned on startup of Django,

otherwise the decorators won’t register the handlers. For instance, for a Django-application, my_app/__init__.py is scanned on startup (provided my_app is in INSTALLED_APPS). So if your handlers are in my_app/events.py, you could load them from there:

# my_app/__init__.py:

# Load handlers for events, so django-eventhandlers picks 'em up
import my_app.events  # NOQA (keep pyflakes happy)

Running tests

Just run python manage.py test to run tests against your current setup. Run tox to run tests for various versions of Django. Currently, Django 1.6 through 1.9 on Python 2.7 are tested.