Basic PubSub

gistfile1.js

window.pubSub = window.pubSub || {};

(function IFEE(pubSub) {
    'use strict';

    var eventStore = {}, lastId = 0;

    pubSub.subscribe = function sub(topic, func) {
        if (!eventStore.hasOwnProperty(topic)) {
            eventStore[topic] = {}; // Was using an array but this seems better for unsub perf.
        }

        lastId += 1; // arrg @ possible race cond. Keeping incrimental ID gen for simplicity of gist.
        eventStore[topic][lastId] = func;
        return lastId;
    };

    pubSub.unsubscribe = function unsub(id) {
        var events, topic;
        for (topic in eventStore)
        {
            if (eventStore.hasOwnProperty(topic))
            {
                events = eventStore[topic];
                delete events[id];
            }
        }
    };

    pubSub.publish = function pub(topic) {
        var events, args, callback;
        if (eventStore.hasOwnProperty(topic)) {
            events = eventStore[topic];
            args = Array.prototype.slice.call(arguments).splice(1, arguments.length);
            for (callback in events)
            {
                if (events.hasOwnProperty(callback))
                {
                    events[callback].apply(this, args);
                }
            }
        }
    };

    pubSub.viewEvents = function () {
        return eventStore;
    };

}(window.pubSub));

///// USAGE

(function IFEE (pubSub) {
    'use strict';

    pubSub.subscribe('index/loaded', function (time, from) {
        console.log("The loaded event was called at ", time, " from ", from);
    });

    pubSub.subscribe('index/loaded', function () {
        console.log("I'm alive!");
    });

    pubSub.subscribe('index/afterLoaded', function () {
        console.log("We made it through. Thanks heavens for that.");
    });

    var pubId = pubSub.subscribe('index/loaded', function () {
        console.log("My time here is somewhat limited");
    });

    pubSub.unsubscribe(pubId);

    function init() {
        pubSub.publish('index/loaded', new Date().getTime(), "index");
    }

    init();
    pubSub.publish('index/afterLoaded');


    console.log(pubSub.viewEvents());

}(window.pubSub));