Installation

To install the latest release from pypi:

pip install gevent-eventemitter

Usage

EventEmitter can be used as mixin, or on it’s own. Here is an example as mixin:

from eventemitter import EventEmitter

class MyClass(EventEmitter):
    pass

instance = MyClass()

Registering a callback

def do_stuff():
    print "Hello world!"

instance.on('my event', do_stuff)

instance.emit('my event')

Or as decorator

@instance.on('my event')
def do_stuff():
    print "Hello world!"

With once the callback will be called, you guessed it, only once.

@instance.once('my event')
def do_stuff(var):
    print "Hello %s!" % var

instance.emit('my event', 'Earth')  # arguments can be passed along events
instance.emit('my event')  # do_stuff won't be called

It’s possible to block wait for an event.

If there are event arguments they will be returned as a tuple

my_args = instance.wait_event('my event')
my_args = instance.wait_event('my event', timeout=5)  # wait at most 5seconds

On timeout wait_event will return None, or raise gevent.Timeout if raises=True

my_args = instance.wait_event('my event', timeout=5)
if my_args is None:
    print "Timeout!"

try:
    my_args = instance.wait_event('my event', timeout=5, raises=True)
except gevent.Timeout:
    print "Timeout!"

To remove a callback, or all callbacks.

instance.remove_listener('my event', do_stuff)
instance.remove_all_listeners()                 # absolutely all listeners
instance.remove_all_listeners('my event')       # all listners for the event

Listening for None event will result in catching all events.