/examples/backbone-localstorage.js
JavaScript | 136 lines | 85 code | 24 blank | 27 comment | 15 complexity | 53de93f852bf76bf5a00fcf13a24b11d MD5 | raw file
- /**
- * Backbone localStorage Adapter
- * https://github.com/jeromegn/Backbone.localStorage
- */
- (function() {
- // 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
- var _ = this._;
- var Backbone = this.Backbone;
- // 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, error) {
- var store = model.localStorage || model.collection.localStorage;
- // Backwards compatibility with Backbone <= 0.3.3
- if (typeof options == 'function') {
- options = {
- success: options,
- error: error
- };
- }
- var resp;
- 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;
- }
- if (resp) {
- options.success(model, resp, options);
- } else {
- options.error(model, "Record not found", options);
- }
- };
- 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, error) {
- return Backbone.getSyncMethod(model).apply(this, [method, model, options, error]);
- };
- })();