nmevent 0.1.1

A simple C#-like implementation of the Observer design pattern.

nmevent - C#-like implementation of the Observer pattern

This is a Python module :mod:`nmevent`, simple C#-like implementation of
the Observer pattern (http://en.wikipedia.org/wiki/Observer_pattern).
It's main purpose and goal is to allow developers to use events
with C#-like syntax in their Python classes.

Usage example
=============

The most straightfoward way to use :mod:`nmevent` is this:

>>> import nmevent
>>> class ExampleClass(object):
... def __init__(self):
... self.event = nmevent.Event()
...
... def _do_something(self):
... self.event(self)
...
>>> example = ExampleClass()
>>> example.event += handler

It should be noted, that event doesn't necessarily need to
be an object attribute. :class:`Event` instance is basically
just a callable object that works as a sort of "dispatch
demultiplexer".

This usage, however, isn't very C#-like. In C#, events are declared
in class scope and that's where the :class:`EventSlot` comes in.
Once you've created event using :class:`EventSlot`, you can
use the same way you use :class:`Event`, only you don't need
to specify the sender when raising the event. That's because
the event is already bound to the instance of the class it has
been declared in.

>>> from nmevent import EventSlot
>>> class ExampleClass(object):
... event = EventSlot()
...
... def _do_something(self):
... self.event()
...
>>> def handler(sender, **keywords):
... pass
...
>>> example = ExampleClass()
>>> example.event += handler

Perhaps this looks even more straightfoward than instantiating
:class:`Event` in object's constructor, but there's actually
lot more going on under hood this time.

>>> import nmevent
>>> @nmevent.with_events
... class ExampleClass(object):
... @nmevent.nmproperty
... def x(self):
... return self._x
...
>>> example = ExampleClass()
>>> example.x_changed += handler
>>> example.x = 10 # handler gets called

License
=======

Copyright (c) 2010, Jan Milík.

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope the it will be useful,
but WITHOUT ANY WARRANTY; without event the implied warranty of
MERCHANTIBILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.