LocalStorage wrapper providing dojo.store interface

LocalStorage.js

define("dojo/store/LocalStorage", ["dojo", "dojo/store/util/QueryResults", "dojo/store/util/SimpleQueryEngine"], function(dojo) {

dojo.declare("dojo.store.LocalStorage", null, {
	constructor: function(/*dojo.store.LocalStorage*/ options){
		// summary:
		//		localStorage based object store.
		// options:
		//		This provides any configuration information that will be mixed into the store.
		// 		This should generally include the data property to provide the starting set of data.
		if (!dojo.global.localStorage){
			throw Error("LocalStorage not available on this device");
		}
		dojo.mixin(this, options);
		this.setData(this.data || []);
	},
	// idProperty: String
	//		Indicates the property to use as the identity property. The values of this
	//		property should be unique.
	idProperty: "id",

	// queryEngine: Function
	//		Defines the query engine to use for querying the data store
	queryEngine: dojo.store.util.SimpleQueryEngine,
	get: function(id){
		//	summary:
		//		Retrieves an object by its identity
		//	id: Number
		//		The identity to use to lookup the object
		//	returns: Object
		//		The object in the store that matches the given id.
		return dojo.fromJson(localStorage.getItem(id));
	},
	getIdentity: function(object){
		// 	summary:
		//		Returns an object's identity
		// 	object: Object
		//		The object to get the identity from
		//	returns: Number
		return object[this.idProperty];
	},
	put: function(object, options){
		// 	summary:
		//		Stores an object
		// 	object: Object
		//		The object to store.
		// 	options: Object?
		//		Additional metadata for storing the data.  Includes an "id"
		//		property if a specific id is to be used.
		//	returns: Number
		var id = options && options.id || object[this.idProperty] || Math.random();
		localStorage.setItem(id,dojo.toJson(object));
		return id;
	},
	add: function(object, options){
		// 	summary:
		//		Creates an object, throws an error if the object already exists
		// 	object: Object
		//		The object to store.
		// 	options: Object?
		//		Additional metadata for storing the data.  Includes an "id"
		//		property if a specific id is to be used.
		//	returns: Number
		if (this.get(object[this.idProperty])){
			throw new Error("Object already exists");
		}
		
		return this.put(object, options);
	},
	remove: function(id){
		// 	summary:
		//		Deletes an object by its identity
		// 	id: Number
		//		The identity to use to delete the object
		localStorage.removeItem(id);
	},
	query: function(query, options){
		// 	summary:
		//		Queries the store for objects.
		// 	query: Object
		//		The query to use for retrieving objects from the store.
		//	options: dojo.store.util.SimpleQueryEngine.__queryOptions?
		//		The optional arguments to apply to the resultset.
		//	returns: dojo.store.util.QueryResults
		//		The results of the query, extended with iterative methods.
		//
		// 	example:
		// 		Given the following store:
		//
		// 	|	var store = new dojo.store.LocalStorage({
		// 	|		data: [
		// 	|			{id: 1, name: "one", prime: false },
		//	|			{id: 2, name: "two", even: true, prime: true},
		//	|			{id: 3, name: "three", prime: true},
		//	|			{id: 4, name: "four", even: true, prime: false},
		//	|			{id: 5, name: "five", prime: true}
		//	|		]
		//	|	});
		//
		//	...find all items where "prime" is true:
		//
		//	|	var results = store.query({ prime: true });
		//
		//	...or find all items where "even" is true:
		//
		//	|	var results = store.query({ even: true });

		var data=[];
		for (var i=0; i<localStorage.length;i++){
			data.push(this.get(localStorage.key(i)));
		}		
		return dojo.store.util.QueryResults(this.queryEngine(query, options)(data));
	},
	setData: function(data){
		// 	summary:
		//		Sets the given data as the source for this store, and indexes it
		//	data: Object[]
		//		An array of objects to use as the source of data.
		if(data.items){
			// just for convenience with the data format IFRS expects
			this.idProperty = data.identifier;
			data = this.data = data.items;
		}

		for(var i = 0, l = data.length; i < l; i++){
			var object = data[i];
			this.put(object);
		}
	}
});

return dojo.store.LocalStorage;
});

@dmachi, see preceding two comments. (Just had to @ mention you to make sure you heard about this.)

@dmachi, can you even see this?