How to implement event-driven JavaScript without involving any DOM element?

Question

Is there any way to implement event-driven programming in JavaScript, without involving any DOM element? Such as creating an event-handler which executed every time an array get sorted.

Answer 1

Sure! The keyword you're looking for is "pubsub". Here are some well-known implementations:

• As a jQuery plugin
• PubSubJS
• EventEmitter2
• Backbone.Events

But you could also do it yourself, like so:

window.pubsub = (function () {     var eventToListeners = {};      return {         sub: function (event, callback) {             if (!eventToListeners.hasOwnProperty(event)) {                 eventToListeners[event] = [];             }             eventToListeners[event].push(callback);         },         pub: function (event, args) {             if (eventToListeners.hasOwnProperty(event)) {                 for (var i = 0; i < eventToListeners[event].length; ++i) {                    try {                        eventToListeners[event][i].call(null, args);                    } catch (e) {                        if (console && console.error) {                            console.error(e);                        }                    }                 }             }         }     }; }());  // Sample usage: pubsub.sub("arraySorted", function () {     console.log("array was sorted"); });  var myArray = [2, 3, 1];  myArray.sort(); pubsub.pub("arraySorted");