Is there a way to bind events to regular objects in javascript?

Question

as subject states, I want to attach events to my objects and trigger its action at future so I can do asynchronous stuff without callbacks and Qs.

I dont want to attach & pollute any particular DOM or the document.

Do you want to attach a function to an object which modifies it when you call the function later or do you want to execute a function on an object which causes a function to be called when a certain specified condition is met ? — ShaneQful
– ShaneQful, Commented Aug 5, 2014 at 23:23
You should look for publish/subscribe pattern or maybe also mixin pattern — Krzysztof Safjanowski
– Krzysztof Safjanowski, Commented Aug 5, 2014 at 23:53

Krzysztof Safjanowski · Accepted Answer · 2014-08-06 00:28:01Z

2

Publish / Subscribe pattern

var utils = utils || {};
utils.publishSubscribe = (function() {

    var publishSubscribe = {};

    // Storage for topics that can be broadcast 
    // or listened to
    var topics = {};

    // An topic identifier
    var subUid = -1;

    // Publish or broadcast events of interest
    // with a specific topic name and arguments
    // such as the data to pass along
    publishSubscribe.publish = function( topic, args ) {

        if ( !topics[topic] ) {
            return false;
        }

        var subscribers = topics[topic],
            len = subscribers ? subscribers.length : 0;

        while (len--) {
            subscribers[len].func( topic, args );
        }

        return this;
    };

    // Subscribe to events of interest
    // with a specific topic name and a
    // callback function, to be executed
    // when the topic/event is observed
    publishSubscribe.subscribe = function( topic, func ) {

        if (!topics[topic]) {
            topics[topic] = [];
        }

        var token = ( ++subUid ).toString();
        topics[topic].push({
            token: token,
            func: func
        });
        return token;
    };

    // Unsubscribe from a specific
    // topic, based on a tokenized reference
    // to the subscription
    publishSubscribe.unsubscribe = function( token ) {
        for ( var m in topics ) {
            if ( topics[m] ) {
                for ( var i = 0, j = topics[m].length; i < j; i++ ) {
                    if ( topics[m][i].token === token ) {
                        topics[m].splice( i, 1 );
                        return token;
                    }
                }
            }
        }
        return this;
    };

    return publishSubscribe;
}());

Usage

utils.publishSubscribe.subscribe( "inbox/newMessage", function( topic, data ) {
    console.log( "A new message was received: ", data );
})

utils.publishSubscribe.publish( "inbox/newMessage", [{
      sender: "[email protected]",
      body: "Hey there! How are you doing today?"
}]);

source: Addy Osmani – Learning JavaScript Design Patterns

answered Aug 6, 2014 at 0:28

Krzysztof Safjanowski

7,4483 gold badges38 silver badges50 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

user2167582 Over a year ago

interesting, so the way to immitate events is by using callbacks.

supercat Over a year ago

I would regard unsubscription as an essential aspect of publish/subscribe, especially in the absence of weak references. Otherwise, event publishers which substantially outlive subscribers will cause memory leaks.

Collectives™ on Stack Overflow

Is there a way to bind events to regular objects in javascript?

1 Answer 1

Publish / Subscribe pattern

Usage

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Publish / Subscribe pattern

Usage

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related