Metadata-Version: 2.0
Name: python-dispatch
Version: 0.0.8
Summary: Lightweight Event Handling
Home-page: https://github.com/nocarryr/python-dispatch
Author: Matthew Reid
Author-email: matt@nomadic-recording.com
License: MIT
Keywords: event properties dispatch
Platform: any
Classifier: Development Status :: 3 - Alpha
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: MIT License
Classifier: Operating System :: OS Independent
Classifier: Programming Language :: Python
Classifier: Topic :: Software Development
Classifier: Programming Language :: Python :: 2
Classifier: Programming Language :: Python :: 2.7
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.4
Classifier: Programming Language :: Python :: 3.5

python-dispatch
===============

Lightweight event handling for Python

`|Build
Status| <https://travis-ci.org/nocarryr/python-dispatch>`_`|Coverage
Status| <https://coveralls.io/github/nocarryr/python-dispatch?branch=master>`_`|PyPI
version| <https://badge.fury.io/py/python-dispatch>`_`|GitHub
license| <https://raw.githubusercontent.com/nocarryr/python-dispatch/master/LICENSE.txt>`_

Description
-----------

This is an implementation of the "Observer Pattern" with inspiration
from the `Kivy <kivy.org>`_ framework. Many of the features though are
intentionally stripped down and more generalized. The goal is to have a
simple drop-in library with no dependencies that stays out of the
programmer's way.

Installation
------------

::

    pip install python-dispatch

Usage
-----

For more information, see the documentation here:
https://nocarryr.github.io/python-dispatch

Events
~~~~~~

::

    from pydispatch import Dispatcher

    class MyEmitter(Dispatcher):
        # Events are defined in classes and subclasses with the '_events_' attribute
        _events_ = ['on_state', 'new_data']
        def do_some_stuff(self):
            # do stuff that makes new data
            data = self.get_some_data()
            # Then emit the change with optional positional and keyword arguments
            self.emit('new_data', data=data)

    # An observer - could inherit from Dispatcher or any other class
    class MyListener(object):
        def on_new_data(self, *args, **kwargs):
            data = kwargs.get('data')
            print('I got data: {}'.format(data))
        def on_emitter_state(self, *args, **kwargs):
            print('emitter state changed')

    emitter = MyEmitter()
    listener = MyListener()

    emitter.bind(on_state=listener.on_emitter_state)
    emitter.bind(new_data=listener.on_new_data)

    emitter.do_some_stuff()
    # >>> I got data: ...

    emitter.emit('on_state')
    # >>> emitter state changed

Properties
~~~~~~~~~~

::

    from pydispatch import Dispatcher, Property

    class MyEmitter(Dispatcher):
        # Property objects are defined and named at the class level.
        # They will become instance attributes that will emit events when their values change
        name = Property()
        value = Property()

    class MyListener(object):
        def on_name(self, instance, value, **kwargs):
            print('emitter name is {}'.format(value))
        def on_value(self, instance, value, **kwargs):
            print('emitter value is {}'.format(value))

    emitter = MyEmitter()
    listener = MyListener()

    emitter.bind(name=listener.on_name, value=listener.on_value)

    emitter.name = 'foo'
    # >>> emitter name is foo
    emitter.value = 42
    # >>> emitter value is 42

.. |Build
Status| image:: https://travis-ci.org/nocarryr/python-dispatch.svg?branch=master
.. |Coverage
Status| image:: https://coveralls.io/repos/github/nocarryr/python-dispatch/badge.svg?branch=master
.. |PyPI version| image:: https://badge.fury.io/py/python-dispatch.svg
.. |GitHub
license| image:: https://img.shields.io/badge/license-MIT-blue.svg


