JavaScript Observer Pattern

var pubsub = {};
(function(q) {
    var topics = {},
        subUid = -1;
    // Publish or broadcast events of interest
    // with a specific topic name and arguments
    // such as the data to pass along
    q.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
    q.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
    q.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;
    };
}( pubsub ));
 
 
//Usage :
 
var testHandler = function (topics, data) {
    console.log(topics + ": " + data);
};
// Subscribers basically "subscribe" (or listen)
// And once they've been "notified" their callback functions are invoke
var testSubscription = pubsub.subscribe('example1', testHandler);
// Publishers are in charge of "publishing" notifications about events
pubsub.publish('example1', 'hello world!');
pubsub.publish('example1', ['test', 'a', 'b', 'c']);
pubsub.publish('example1', [{
  'color': 'blue'
}, {
  'text': 'hello'
}]);
// Unsubscribe if you no longer wish to be notified
pubsub.unsubscribe(testSubscription);
// This will fail
pubsub.publish('example1', 'hello again! (this will fail)');