Composability vs "inheritance" in Flux's Stores

index.js

/*
The intention behind this example is to demonstrate how to **compose**
instead of **inherit**, this simplifies the code by using EventEmmitter
as a service instead of using the pattern know as Prototypal inheritance
which is know to have several draw backs, since it **does not work
like clasical inheritance**


Example Extracted from  https://scotch.io/tutorials/getting-to-know-flux-the-react-js-architecture
*/

var AppDispatcher = require('../dispatcher/AppDispatcher');
var ShoeConstants = require('../constants/ShoeConstants');
var EventEmitter = require('events').EventEmitter;

// Internal object of shoes
var _shoes = {};

// Method to load shoes from action data
function loadShoes(data) {
  _shoes = data.shoes;
}

//Internal event emitter "service"
var emitter = new EventEmitter();

// Use  Node's Event Emitter in the ShoeStore
var ShoeStore = {

  // Returns all shoes
  getShoes: function() {
    return _shoes;
  },

  emitChange: function() {
    emitter.emit('change');
  },

  addChangeListener: function(callback) {
    emitter.on('change', callback);
  },

  removeChangeListener: function(callback) {
    emitter.removeListener('change', callback);
  }

});

// Register dispatcher callback
AppDispatcher.register(function(payload) {
  var action = payload.action;
  var text;
  // Define what to do for certain actions
  switch(action.actionType) {
    case ShoeConstants.LOAD_SHOES:
      // Call internal method based upon dispatched action
      loadShoes(action.data);
      break;

    default:
      return true;
  }
  
  // If action was acted upon, emit change event
  ShoeStore.emitChange();

  return true;

});

module.exports = ShoeStore;

Other things that we could do to reduce the Store's boilerplate is to use some pattern to avoid rewriting emitChange, addChangeListener and removeChangeListener every time we write a store.