proxy.js

// Element store
const elementStore = class ElementStore {
  // set initial state
  @observable path = null
  @observable visible = false
  @observable list = {}

  // create a new instance of element store
  constructor() {
    this.list = sortElementsByName(elements)
  }

  // dynamically handle element events
  handle(handlerName, {path}) {
    switch (handlerName) {
      case HIDE_ELEMENTS:
        this.on(HIDE_ELEMENTS, store => console.log(store));
        break;
      case SHOW_ELEMENTS:
        this.on(SHOW_ELEMENTS, (store, {path}) => console.log(store));
        break;
      case "UPDATE_RECENT_USED_ELEMENT_TIMESTAMP":
        this.on("UPDATE_RECENT_USED_ELEMENT_TIMESTAMP", updateRecentUsedTimestamp);
        break;
    }
  }

 // get elements list.
 // also dynamically bind get method for fetching element property.
  getList() {
    return _.map(this.list, (element) => {
      element.get = (arg) => _.pick(element, [arg])[arg];
      return element;
    });
  }
}

// instance of element store
let store = new elementStore();

/**
 * Uses proxy for the element store.
 **/
export default new Proxy(store, {
  get(target, prop) {
      if(target[prop] === undefined) {
          return (...args) => _.map(elements, (element) => {
            let e = _.pick(element, [args[0]])

            // dynamically method binding...
            e.get = (arg) => _.pick(element, [arg])[arg];

            return e;
          });
      } else {
        return target[prop];
      }
  },
 set(target, prop) {
   // set call handeler....
 }
});

export default proxyStore;

/**
 * example:
 *
 * let store = new ElementStore();
 * store.get('groups'); // undefined function error
 * 
 *
 * let proxyElementStore = proxyStore;
 * proxyElementStore.get('groups'); // returns array of elements data.
 *
 **/