/**
* Backbone localStorage Adapter
* Version 1.0
*
* https://github.com/jeromegn/Backbone.localStorage
*/
(function (root, factory) {
if (typeof define === "function" && define.amd) {
// AMD. Register as an anonymous module.
define(["underscore", "backbone"], function (_, Backbone) {
// Use global variables if the locals is undefined.
return factory(_ || root._, Backbone || root.Backbone);
});
} else {
// RequireJS isn't being used. Assume underscore and backbone is loaded in <script> tags
factory(_, Backbone);
}
}(this, 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 this.find(model);
},
// 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 this.find(model);
},
// Retrieve a model from `this.data` by id.
find: function (model) {
return this.jsonData(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 this.jsonData(this.localStorage().getItem(this.name + "-" + id));
}, this)
.compact()
.value();
},
// Delete a model from `this.data`, returning it.
destroy: function (model) {
if (model.isNew())
return false
this.localStorage().removeItem(this.name + "-" + model.id);
this.records = _.reject(this.records, function (id) {
return id === model.id.toString();
});
this.save();
return model;
},
localStorage: function () {
return localStorage;
},
// fix for "illegal access" error on Android when JSON.parse is passed null
jsonData: function (data) {
return data && JSON.parse(data);
}
});
// 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, errorMessage, syncDfd = $.Deferred && $.Deferred(); //If $ is having Deferred - use it.
try {
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;
}
} catch (error) {
if (error.code === DOMException.QUOTA_EXCEEDED_ERR && window.localStorage.length === 0)
errorMessage = "Private browsing is unsupported";
else
errorMessage = error.message;
}
if (resp) {
if (options && options.success)
if (Backbone.VERSION === "0.9.10") {
options.success(model, resp, options);
} else {
options.success(resp);
}
if (syncDfd)
syncDfd.resolve(resp);
} else {
errorMessage = errorMessage ? errorMessage
: "Record Not Found";
if (options && options.error)
if (Backbone.VERSION === "0.9.10") {
options.error(model, errorMessage, options);
} else {
options.error(errorMessage);
}
if (syncDfd)
syncDfd.reject(errorMessage);
}
// add compatibility with $.ajax
// always execute callback for success and error
if (options && options.complete)
options.complete(resp);
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]);
};
return Backbone.LocalStorage;
}));
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