README

dissemination

Lightweight event/command library created to replace Backbone.Radio in projects ported from Backbone/Marionette to React.

Installation

npm install dissemination --save

Usage

ES6:

import dissemination from 'dissemination';

require with Node.js:

var dissemination = require('dissemination');

in browser include dist/dissemination.js or dist/dissemination.min.js script:
```
var dissemination = window.dissemination;
```

and then

dissemination().on('event', function() { console.log('event is fired'); });
dissemination().fire('event');

Examples

Channel

get default channel (with application name):
```
const c = dissemination();
```
get named channel:
```
const c = dissemination('myChannel');
```

create channel directly:

import { Channel } from 'dissemination';
const c = new Channel();

Events

add event listener:

const listener = () => { console.log('event is fired'); };
dissemination().on('event', listener);

remove specific event listener:

dissemination().off('event', listener);

remove all event listeners for a given event:
```
dissemination().off('event');
```
fire event:
```
dissemination().fire('event');
```

fire event with parameters:

const listener = params => {
  console.log(params); // => { item: 1 }
};
dissemination().on('event', listener);
dissemination().fire('event', { item: 1 });

add event listener with additional options:

const listener = (params, options) => {
  console.log(params); // => { item: 1 }
  console.log(options); // => { message: 'hello world' }
};
dissemination().on('event', listener, {
  message: 'hello world'      
});
dissemination().fire('event', { item: 1 });

add event listener that will be executed once:

let count = 0;
const listener = () => { count += 1; };
dissemination().once('event', listener);
dissemination().fire('event');
dissemination().fire('event');
console.log(count); // => 1

interrupt event listeners' execution chain:

let result = 0;
const listener1 = () => { result += 1; return false; };
const listener2 = () => { result += 2; };
dissemination().on('event', listener1);
dissemination().on('event', listener2);
dissemination().fire('event');
console.log(result); // => 1

check whether event listeners are registered:

const listener = () => { console.log('event is fired'); };
dissemination().on('event', listener);
console.log(dissemination().listenersRegistered('event')); // => true

Commands

add command handler:

const handler = () => { console.log('command is handled'); };
dissemination().handle('command', handler);

remove specific command handler:
```
dissemination().unhandle('command');
```
execute command:
```
dissemination().execute('command');
```

execute command with response result:

const handler = () => { return 1 };
dissemination().handle('command', handler);
console.log(dissemination().request('command')); // => 1

add command handler with additional options:

const positive = options => options.number >= 0;
dissemination().handle('positive', positive);
console.log(dissemination().request('positive', { number: 2 })); // => true
console.log(dissemination().request('positive', { number: -1 })); // => false

check whether command handler is registered:

const handler = () => { console.log('command is handled'); };
dissemination().handle('command', handler);
console.log(dissemination().handlerRegistered('command')); // => true

Mixins

add EventMixin or/and CommandMixin to any custom object:

import { EventMixin } from 'dissemination';
const events = Object.assign({}, EventMixin);
events.on('event', () => { console.log('event is fired'); });
events.fire('event');

import { CommandMixin } from 'dissemination';
const commands = Object.assign({}, CommandMixin);
commands.handle('command', function() { return 'hello world'; });
console.log(commands.request('command')); // => 'hello world'

Building

In order to build library run:

npm run build

Testing

Run unit tests:

npm test

Run tests with coverage:

npm run test:coverage

In order to run tests with Coveralls locally you have to provide COVERALLS_REPO_TOKEN:

COVERALLS_REPO_TOKEN=<token> npm run test:coverage

Contributing

Before making a pull request, please, be sure that you are starting from develop branch.

License

MIT

Usage no npm install needed!