event.js

simple event implement

import

npm install -S @hudk/event

usage

var Event = require('@hudk/event');
var e = new Event();

api

trigger(eventName, [message])

trigger event

e.trigger('trigger', { author: hudk });

on(eventName, callback, [context])

add callback, which will always be triggered when event happens

var obj = { a: 3 }; 
e.on('on', val => console.log(val));
e.on('on', _ => console.log(this.a), obj); // the this would be global if without context
e.trigger('on', 5); // 5 3
e.trigger('on', 7); // 7 3

once(eventName, callback, [context])

add callback, which will only be triggered once

var obj = { a: 3 }; 
e.on('once', val => console.log(val));
e.on('once', _ => console.log(this.a), obj);
e.trigger('once', 5); // 5 3
e.trigger('once', 7); // no output

stop(eventName)

stop event from continue triggering

e.once('stop', _ => {
  e.stop('stop');
});
e.once('stop', _ => console.log(3));
e.trigger('stop') // no output
e.trigger('stop') // 3

stop should only used in once, or all your callbacks defined later won't be triggered