Global event system for React.js

EventSystem.js

let EventSystem = (function() {
    this.queue = {};

    return {
        publish: (event, data) => {
            let queue = this.queue[event];

            if (typeof queue === 'undefined') {
                return false;
            }

            while(queue.length > 0) {
                (queue.shift())(data);
            }

            return true;
        },
        subscribe: (event, callback) => {
            if (typeof this.queue[event] === 'undefined') {
                this.queue[event] = [];
            }

            this.queue[event].push(callback);
        }
    };
}());

sample-usage-to-publish.js

var RiskList = React.createClass({
  getInitialState: function() {
    return { risks: [] };
  },
  componentDidMount: function() {
    // someting
  },
  render: function() {
    EventSystem.publish('risk.count.update', this.state.risks.length);
    // something
  }
}

sample-usage-to-subscribe.js

var RiskPage = React.createClass({
  updateRiskCount: function(count) {
    this.setState({
      riskCount: count
    });
  },
  componentDidMount: function() {
    EventSystem.subscribe('risk.count.update', this.updateRiskCount);
  },
  getInitialState: function() {
    return {
      riskCount: 0
    };
  },
  render: function() {
    // something
  }
});