events-merge v1.2.1

A small utility for merging two+ EventEmitters together.

Installing

$ npm install --save events-merge

Testing

$ cd events-merge
$ npm install --only=dev
$ npm test

Getting Started

var merge   = require('events-merge');
var Emitter = require('events').EventEmitter;

var counter = 0;
var base = new Emitter();
var emitters = [
  new Emitter(),
  new Emitter()
];

base.on('inc', () => { counter++ });
emitters[0].on('inc', () => { counter++ });
emitters[1].on('dec', () => { counter-- });

merge.to(base).emitters(emitters);

base.emit('inc'); // counter == 2
base.emit('inc'); // counter == 4
base.emit('dec'); // counter == 3

or simply

var merge = require('events-merge').merge;

// code code code...

merge(base, emitter1, emitter2, ...); // base is now merged with the given emitters.

Using the es6 flavor

merge uses the es5 syntax by default. If your node.js version does not support es6 syntax, you can overcome this problem by requiring events-merge/es5 lib instead.

var merge = require('events-merge/es6');

NOTICE that require('events-merge/es6').merge shortcut DOESN'T work, so use the es6 flavor only with the oop api.

API

merge.set(key:String, value) : self

Sets a default option for the events-merge module.

merge.set('overwrite', true);

merge.base(emitter:Emitter) : self

Sets a base emitter to merge other emitters to.

merge.base(emitter).emitters(emitter1, emitter2, ...);

merge.to(emitter:Emitter) : self

Alias to merge.base.

merge.to(emitter).merge(emitter1, emitter2, ...);

merge.merge(...emitters:Emitter) : Emitter

merge.merge(emitters:Array) : Emitter

Merge the given emitters (by array or by seperated param) to the base emitter. If not base emitter given, uses the first emitter in the given emitters list.

var merge = require('events-merge').merge;
merge(base, emitter1, emitter2, ...); // base is now merged with the given emitters.

merge.emitters(...emitters:Emitter) : Emitter

merge.emitters(emitters:Array) : Emitter

Alias for merge.merge.

[getter] merge.overwrite

Sets the overwrite flag to true.

merge.overwrite.to(base).merge(emitter1, emitter2, ...);

[static] merge.eventNamesOf(emitter:Emitter) : Array

A helper method that returns list of event names that a given emitter holds.

emitter.on('ev1', someMethod);
emitter.on('ev2', anotherMethod);

console.log(merge.eventNamesOf(emitter)); // prints ['ev1', 'ev2'].

LICENSE

MIT

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