7.3 KiB
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!
See NPM stats for event-pubsub
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'
);