todomvc/examples/dojo/js/todo/store/LocalStorage.js

> Helping you select an MV\* framework

/**
* Original source from https://gist.github.com/880822
* Converted to AMD-baseless format
*/
define(["dojo/_base/declare", "dojo/_base/lang", "dojo/_base/json", "dojo/store/util/QueryResults", "dojo/store/util/SimpleQueryEngine"],
    function(declare, lang, json, QueryResults, SimpleQueryEngine) {

    return declare(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 (!window.localStorage){
                throw Error("LocalStorage not available on this device");
            }
            lang.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: 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 json.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, json.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 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);
            }
        }
    });
});