simple javascript event bus for handling lots of stuff

eventbus.js

var EventBus = (function () {
  var topics = {};
  return {
    subscribe: function (topic, listener) {
      if (!topics[topic]) {
        topics[topic] = [];
      }

      topics[topic].push(listener);
    },

    publish: function (topic, data) {
      var listeners = topics[topic];
      if (!listeners || listeners.length < 1) {
        return;
      }

      listeners
        .forEach(function (listener) {
          listener(data);
        });
    }
  };
}());