Async version of the backbone.localStorage module

backbone.localStorage.async.js

/**
 * Backbone localStorage Adapter
 * https://github.com/jeromegn/Backbone.localStorage
 */
_ = require('underscore');
$ = require('jquery');
(function(_, Backbone) {
// A simple module to replace `Backbone.sync` with *localStorage*-based
// persistence. Models are given GUIDS, and saved into a JSON object. Simple
// as that.

// Hold reference to Underscore.js and Backbone.js in the closure in order
// to make things work even if they are removed from the global namespace

// Generate four random hex digits.
function S4() {
   return (((1+Math.random())*0x10000)|0).toString(16).substring(1);
};

// Generate a pseudo-GUID by concatenating random hexadecimal.
function guid() {
   return (S4()+S4()+"-"+S4()+"-"+S4()+"-"+S4()+"-"+S4()+S4()+S4());
};

// Our Store is represented by a single JS object in *localStorage*. Create it
// with a meaningful name, like the name you'd give a table.
// window.Store is deprectated, use Backbone.LocalStorage instead
Backbone.LocalStorage = window.Store = function(name) {
  this.name = name;
  var store = this.localStorage().getItem(this.name);
  this.records = (store && store.split(",")) || [];
};

_.extend(Backbone.LocalStorage.prototype, {

  // Save the current state of the **Store** to *localStorage*.
  save: function() {
    this.localStorage().setItem(this.name, this.records.join(","));
  },

  // Add a model, giving it a (hopefully)-unique GUID, if it doesn't already
  // have an id of it's own.
  create: function(model) {
    if (!model.id) {
        model.id = guid();
        model.set(model.idAttribute, model.id);
    }
    this.localStorage().setItem(this.name+"-"+model.id, JSON.stringify(model));
    this.records.push(model.id.toString());
    this.save();
    return model.toJSON();
  },

  // Update a model by replacing its copy in `this.data`.
  update: function(model) {
    this.localStorage().setItem(this.name+"-"+model.id, JSON.stringify(model));
    if (!_.include(this.records, model.id.toString())) this.records.push(model.id.toString()); this.save();
    return model.toJSON();
  },

  // Retrieve a model from `this.data` by id.
  find: function(model) {
    return JSON.parse(this.localStorage().getItem(this.name+"-"+model.id));
  },

  // Return the array of all models currently in storage.
  findAll: function() {
    return _(this.records).chain()
        .map(function(id){return JSON.parse(this.localStorage().getItem(this.name+"-"+id));}, this)
        .compact()
        .value();
  },

  // Delete a model from `this.data`, returning it.
  destroy: function(model) {
    this.localStorage().removeItem(this.name+"-"+model.id);
    this.records = _.reject(this.records, function(record_id){return record_id == model.id.toString();});
    this.save();
    return model;
  },

  localStorage: function() {
      return localStorage;
  }

});

// localSync delegate to the model or collection's
// *localStorage* property, which should be an instance of `Store`.
// window.Store.sync and Backbone.localSync is deprectated, use Backbone.LocalStorage.sync instead
Backbone.LocalStorage.sync = window.Store.sync = Backbone.localSync = function(method, model, options) {
  var store = model.localStorage || model.collection.localStorage;

  var resp, syncDfd = $.Deferred && $.Deferred(); //If $ is having Deferred - use it. 

  switch (method) {
    case "read":    resp = model.id != undefined ? store.find(model) : store.findAll(); break;
    case "create":  resp = store.create(model);                            break;
    case "update":  resp = store.update(model);                            break;
    case "delete":  resp = store.destroy(model);                           break;
  }
  var res = function(){
    if (resp) {
      if (options && options.success) options.success(resp);
      if (syncDfd) syncDfd.resolve();
    } else {
      if (options && options.error) options.error("Record not found");
      if (syncDfd) syncDfd.reject();
    }
  }
  setTimeout(res,30);

  return syncDfd && syncDfd.promise();
};

Backbone.ajaxSync = Backbone.sync;

Backbone.getSyncMethod = function(model) {
  if(model.localStorage || (model.collection && model.collection.localStorage))
  {
    return Backbone.localSync;
  }

  return Backbone.ajaxSync;
};

// Override 'Backbone.sync' to default to localSync,
// the original 'Backbone.sync' is still available in 'Backbone.ajaxSync'
Backbone.sync = function(method, model, options) {
  return Backbone.getSyncMethod(model).apply(this, [method, model, options]);
};

})(_, Backbone);

package.json

{
  "name": "backbone.localstorage.async",
  "version": "0.1.0",
  "description": "https://gist.github.com/umeboshi2/958efc9f0e76a4d72e5b84e92355e416",
  "main": "backbone.localStorage.async.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "repository": {
    "type": "git",
    "url": "git+ssh://git@gist.github.com/958efc9f0e76a4d72e5b84e92355e416.git"
  },
  "author": "",
  "license": "ISC",
  "bugs": {
    "url": "https://gist.github.com/958efc9f0e76a4d72e5b84e92355e416"
  },
  "homepage": "https://gist.github.com/958efc9f0e76a4d72e5b84e92355e416"
}