@vitorluizc/persistence/dist/persistence.umd.js

Persistence provides a pretty easy API to handle Storage's implementations.

(function (global, factory) {
  typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
  typeof define === 'function' && define.amd ? define(factory) :
  (global = global || self, global.persistence = factory());
}(this, function () { 'use strict';

  /**
   * Creates a Persistence, an object to easily get and set values to a persistent
   * storage like `SessionStorage` or `LocalStorage`.
   * @example ```js
   * const state = createPersistence('state@name', {
   *   placeholder: 'Unknown'
   * });
   *
   * // This creates a persistent field's value.
   * const el = document.querySelector('input[name="name"]');
   * el.value = state.get();
   * el.addEventListener('input', () => state.set(el.value));```
   * @param name - Persistence uses the name as storage's key.
   * @param options - Options to set timeout, storage and placeholder value.
   */

  var createPersistence = function (name, options) {
    if (options === void 0) { options = {}; }
    var storage = options.storage;
    if (storage === void 0) { storage = window.localStorage; }
    var timeout = options.timeout;
    var placeholder = options.placeholder;

    var isExpired = function (updatedAt) {
      return timeout !== undefined && Date.now() > updatedAt + timeout;
    };

    return {
      set: function (value) {
        var state = JSON.stringify({
          value: value,
          updatedAt: Date.now()
        });
        storage.setItem(name, state);
      },
      get: function () {
        var state = storage.getItem(name);

        if (state === null) {
          return placeholder;
        }

        var record = JSON.parse(state);
        return isExpired(record.updatedAt) ? placeholder : record.value;
      },
      delete: function () {
        return storage.removeItem(name);
      }
    };
  };

  var persistence = createPersistence;

  return persistence;

}));