Embedded flux entity class in Store with custom getters for associations

gistfile1.js

import { Store } from 'flummox';
import React from 'react/addons';

export default class UserStore extends Store {

  constructor(flux) {
    super();

    this.registerAll(this.addUsers);

    this.state = {
      users: {}
    };

    this.userClass = class User {
      constructor(props) {
        Object.assign(this, props);
        this._postIds = props.posts;
      }

      get posts() {
        // PostStore would have a similar embedded Post class and getPosts as this Store.
        return flux.getStore('posts').getPosts(this._postIds);
      }
      
    };
    
  }

  addUsers(response) {
    if (checkIfHasEntities(response, 'users') === false) return;

    var userEntities = {};
    for (let user in response.entities.users) {
      userEntities[user] = new this.userClass(response.entities.users[user]);
    }

    let nextState = React.addons.update(this.state, {
      users: {$merge: userEntities}
    });
    
    this.setState(nextState);
  }

  getUsers(ids) {
    return ids.map(id => this.state.users[id]);
  }

}