elliptical-observe/lib-node/store.js

Sideways Data Loading for Elliptical

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = createStore;

var _lodash = require('lodash');

var _lodash2 = _interopRequireDefault(_lodash);

var _zenObservable = require('zen-observable');

var _zenObservable2 = _interopRequireDefault(_zenObservable);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

function createStore() {
  const items = [];
  let observer;
  const data = new _zenObservable2.default(newObserver => {
    observer = newObserver;
  });

  function register(element) {
    const existing = _lodash2.default.find(items, item => _lodash2.default.isEqual(element, item.element));

    if (existing) {
      return existing.value;
    } else {
      const newItem = { element: element };
      items.push(newItem);

      const fetched = element.type.fetch(element);

      const subscription = fetched.subscribe({
        next: function next(value) {
          newItem.value = value;

          if (observer) {
            observer.next({ element: element, value: value });
          }
        }
      });
      newItem.subscription = subscription;

      return newItem.value;
    }
  }

  function remove(item) {
    const index = items.indexOf(item);
    const removed = items.splice(index, 1);
    removed[0].subscription.unsubscribe();
  }

  return { data: data, register: register, items: items, remove: remove };
}