Metadata-Version: 2.1
Name: python-dispatch
Version: 0.1.32
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
Classifier: Programming Language :: Python :: 3.6
Classifier: Programming Language :: Python :: 3.7
Classifier: Programming Language :: Python :: 3.8
Description-Content-Type: text/markdown
License-File: LICENSE.txt

# python-dispatch
Lightweight event handling for Python

[![Build Status](https://travis-ci.org/nocarryr/python-dispatch.svg?branch=master)](https://travis-ci.org/nocarryr/python-dispatch)[![Coverage Status](https://coveralls.io/repos/github/nocarryr/python-dispatch/badge.svg?branch=master)](https://coveralls.io/github/nocarryr/python-dispatch?branch=master)[![PyPI version](https://badge.fury.io/py/python-dispatch.svg)](https://badge.fury.io/py/python-dispatch)[![GitHub license](https://img.shields.io/badge/license-MIT-blue.svg)](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
"python-dispatch" is available on [PyPI](https://pypi.org/project/python-dispatch/)
and can be installed using pip:

```bash
pip install python-dispatch
```

### Python Requirements
After version `0.1` of this project, only Python 3.6 and above will be supported.
If using an older Python version, the older releases should still be available
on PyPI and the correct package should be chosen automatically by `pip`.
If not, either upgrade `pip` and `setuptools`:

```bash
pip install -U pip setuptools
```

Or specify the version manually:

```bash
pip install python-dispatch<0.2
```

## Links

|               |                                              |
| -------------:|:-------------------------------------------- |
| Project Home  | https://github.com/nocarryr/python-dispatch  |
| PyPI          | https://pypi.python.org/pypi/python-dispatch |
| Documentation | https://python-dispatch.readthedocs.io       |


## Usage

### Events

```python
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

```python
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
```

## Contributing

Contributions are welcome!

If you want to contribute through code or documentation, please see the
[Contributing Guide](CONTRIBUTING.md) for information.

## License

This project is released under the MIT License. See the [LICENSE](LICENSE.txt) file
for more information.


