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Event PubSub

npm info :

GitHub info :

Super light and fast Extensible PubSub events and EventEmitters for Node and the browser with support for ES6 by default, and ES5 versions for older verions of node and older IE/Safari versions.

For older versions of node and io.js the latest versions of event-pubsub may work with the --harmony flag. Officially though, we support node v4 and newer with es5 and es6

Easy for any developer level. No frills, just high speed events following the publisher subscriber pattern!

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EXAMPLE FILES

Node Install
npm i --save event-pubsub
By default the correct version (ES5/ES6) will be included. You can force the es5/6 version by requiring event-pubsub/es5 or event-pubsub/es6.

Browser Install
see browser examples above or below


<script src='path/to/event-pubsub-browser.js'></script>
<!-- OR ES5 for older browser support
    <script src='path/to/event-pubsub-browser-es5.js'></script>
-->

Methods

Method	Arguments	Description
subscribe	type (string), handler(function), once (bool/optional)	will bind the `handler` function to the the `type` event. Just like `addEventListener` in the browser. If once is set to true the hander will be removed after being called once.
on	same as above	same as above
once	type (string), handler(function)	will bind the `handler` function to the the `type` event and unbind it after one execution. Just like `addEventListener` in the browser withe the `once` option set
unSubscribe	type (string), handler(function or *)	will unbind the `handler` function from the the `type` event. If the `handler` is `*`, all handlers for the event type will be removed. Just like `removeEventListener` in the browser, but also can remove all event handlers for the type.
off	same as above	same as above
publish	type (string), ...data arguments	will call all `handler` functions bound to the event `type` and pass all `...data arguments` to those handlers
emit	same as above	same as above
trigger	same as above	same as above

While publish, subscribe, and unSubscribe are the proper method names for the publisher/subscriber model, we have included on, off, and emit as well because these are the most common event method names, and shorter. We have also kept the trigger method as an alias for publish and emit for backwards compatability with earlier versions of event-pubsub.

The `*` type

The * type is a special event type that will be triggered by any publish or emit the handlers for these should expect the first argument to be the type and all arguments after to be data arguments.

Basic Examples

NOTE - the only difference between node and browser code is how the events variable is created

node const events = new Events
browser const events = new window.EventPubSub;

Node


// ES5/ES6 now automatically chosen based on node version
const Events = new require('event-pubsub');
const events=new Events;

events.on(
    'hello',
    function(data){
        console.log('hello event recieved ', data);
        events.emit(
            'world',
            {
                type:'myObject',
                data:{
                    x:'YAY, Objects!'
                }
            }
        )
    }
);

events.on(
    'world',
    function(data){
        console.log('World event got',data);
        events.off('*','*');
        console.log('Removed all events');
    }
);

events.emit(
    'hello',
    'world'
);

Basic Chaining


events.on(
    'hello',
    someFunction
).on(
    'goodbye',
    anotherFunction
).emit(
    'hello',
    'world'
);

events.emit(
    'goodbye',
    'complexity'
).off(
    'hello',
    '*'
);

Browser

HTML



    <!DOCTYPE html>
    <html>
        <head>
            <title>PubSub Example</title>
            <script src='../../event-pubsub-browser.js'></script>
            <!-- OR ES5 for older browser support
                <script src='../../event-pubsub-browser-es5.js'></script>
            -->
            <script src='yourAmazingCode.js'></script>
        </head>
        <body>
            ...
        </body>
    </html>

Inside Your Amazing Code


var events = new window.EventPubSub();

events.on(
    'hello',
    function(data){
        console.log('hello event recieved ', data);
        events.emit(
            'world',
            {
                type:'myObject',
                data:{
                    x:'YAY, Objects!'
                }
            }
        )
    }
);

 events.emit(
     'hello',
     'world'
 );

 events.emit(
     'hello',
     'again','and again'
 );

Basic Event Emitter and/or Extending Event PubSub


// ES5/ES6 now automatically chosen based on node version
const Events = require('event-pubsub');
// manually include es6
// const Events = require('event-pubsub/es6');

class Book extends Events{
    constructor(){
        super();
        //now Book has .on, .off, and .emit

        this.words=[];
    }

    add(...words){
        this.words.push(...words);
        this.emit(
            'added',
            ...words
        );
    }

    read(){
        this.emit(
            'reading'
        );
        console.log(this.words.join(' '));
    }
}

const book=new Book;

book.on(
    'added',
    function(...words){
        console.log('words added : ',words);
        this.read();
    }
);

book.add(
    'once','upon','a','time','in','a','cubicle'
);

ES5 extention example


// manually include es5
const Events = require('event-pubsub/es5.js');

function Book(){
    //extend happens below
    Object.assign(this,new Events);
    //now Book has .on, .off, and .emit

    this.words=[];
    this.add=add;
    this.erase=erase;
    this.read=read;

    function add(){
        arguments.slice=Array.prototype.slice;

        this.words=this.words.concat(
            arguments.slice()
        );
        this.emit(
            'added',
            arguments.slice()
        );
    }

    function read(){
        this.emit(
            'reading'
        );
        console.log(this.words.join(' '));
    }

    return this;
};

const book=new Book;

book.on(
    'added',
    function(...words){
        console.log('words added : ',words);
        this.read();
    }
);

book.add(
    'once','upon','a','time','in','a','cubicle'
);

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