event-emitter-grouped

Event Emitter Grouped

Emit events in serial or parallel with support for synchronous and asynchronous listeners

Install

1. Install Node.js
2. npm install --save event-emitter-grouped

Usage

// Importer
var EventEmitterGrouped = require('event-emitter-grouped').EventEmitterGrouped;

// Instantiate a new instance
var emitter = new EventEmitterGrouped();

// Bind an asynchronous event
emitter.on('hello', function(next){
	console.log('\tasync started');
	setTimeout(function(){
		console.log('\tasync finished');
		next();
	}, 1000);
});

// Bind a synchronous event
emitter.on('hello', function(){
	console.log('\tsync started and finished');
});

// Bind a prioritized event
vipListener = function(){
	console.log('\tvip started and finished');
};
vipListener.priority = 1;
emitter.on('hello', vipListener);

// Emit the events in serial (one after the other in a waiting fashion)
console.log('hello in serial started');
emitter.emitSerial('hello', function(err){
	console.log('hello in serial finished');

	// Emit the events in parallel (all at once)
	console.log('hello in parallel started');
	emitter.emitParallel('hello', function(err){
		console.log('hello in parallel finished');
	});
});

/* Outputs:
hello in serial started
	vip started and finished
	async started
	async finished
	sync started and finished
hello in serial finished
hello in parallel started
	vip started and finished
	async started
	sync started and finished
	async finished
hello in parallel finished
*/

EventEmitterGrouped, extends events.EventEmitter

• getListenerGroup(eventName, args..., next?) - returns a TaskGroup where each listener is a task, ordered by the highest priority listeners first
  • eventName is the event that we should get the listeners for
  • args... is an optional set of arguments that should be passed to the listeners when they are executed
  • next is an optional completion callback that will fire once all the tasks/listeners have compeleted
• off - alias for events.EventEmitter.prototype.removeListener
• emitSerial(eventName, args..., next?) - fetch the listener group and execute it in serial
• emitParallel(eventName, args..., next?) - fetch the listener group and execute it in parallel

History

You can discover the history inside the History.md file

License

Licensed under the incredibly permissive MIT License
Copyright © 2013+ Bevry Pty Ltd
Copyright © 2011-2012 Benjamin Arthur Lupton

Changelog

v2.3.0 2013 July 12

• Split out from bal-util
• Added support for splat arguments