store with Immutable

store-immutable.js

define([
	'immutable/immutable',
], function (immutable) {
	var MemoryStore = function MemoryStore () {
		this.constructor.apply(this, arguments);
	};

	MemoryStore.prototype = {
		constructor: function (options) {
			options = options || {};

			this._collection = immutable.fromJS(options.data);
		},

		get: function (id) {
			return this._collection.get(id).toJS();
		},

		add: function (item) {
			if (this._collection.has(item.id)) {
				throw new Error('Item with id ' + item.id + ' already exists.');
			}

			// TODO: perhaps a reviver function passed to 'fromJS' can handle id properties
			// named something other than 'id'
			this._collection = this._collection.push(immutable.fromJS(item));
		},

		put: function (item) {
			if (this._collection.has(item.id)) {
				// TODO: maybe use 'update' or 'merge' methods?
				this._collection = this._collection.set(item.id, item);
			}
			else {
				this._collection = this._collection.push(immutable.fromJS(item));
			}
		},

		delete: function (id) {
			this._collection = this._collection.delete(id);
		},

		orderBy: function (name, descending) {
			return this._collection.sort(function (valueA, valueB) {
				if (valueA[name] < valueB[name]) {
					return (descending ? 1 : -1);
				}
				else if (valueB[name] < valueA[name]) {
					return (descending ? -1 : 1);
				}
				else {
					return 0;
				}
			})
		}
	};

	return MemoryStore;
});