Memory.js #1

/*
	Copyright (c) 2004-2011, The Dojo Foundation All Rights Reserved.
	Available via Academic Free License >= 2.1 OR the modified BSD license.
	see: http://dojotoolkit.org/license for details
*/


if(!dojo._hasResource["dojo.store.Memory"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
dojo._hasResource["dojo.store.Memory"] = true;
dojo.provide("dojo.store.Memory");
dojo.require("dojo.store.util.QueryResults");
dojo.require("dojo.store.util.SimpleQueryEngine");


dojo.declare("dojo.store.Memory", null, {
	// summary:
	//		This is a basic in-memory object store. It implements dojo.store.api.Store.
	constructor: function(/*dojo.store.Memory*/ options){
		// summary:
		//		Creates a memory 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.
		this.index = {};
		dojo.mixin(this, options);
		this.setData(this.data || []);
	},
	// data: Array
	//		The array of all the objects in the memory store
	data:null,

	// idProperty: String
	//		Indicates the property to use as the identity property. The values of this
	//		property should be unique.
	idProperty: "id",

	// index: Object
	//		An index of data by id
	index:null,

	// 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 this.index[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: dojo.store.api.Store.PutDirectives??
		//		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();
		this.index[id] = object;
		var data = this.data,
			idProperty = this.idProperty;
		for(var i = 0, l = data.length; i < l; i++){
			if(data[i][idProperty] == id){
				data[i] = object;
				return id;
			}
		}
		this.data.push(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: dojo.store.api.Store.PutDirectives??
		//		Additional metadata for storing the data.  Includes an "id"
		//		property if a specific id is to be used.
		//	returns: Number
		if(this.index[options && options.id || 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
		delete this.index[id];
		var data = this.data,
			idProperty = this.idProperty;
		for(var i = 0, l = data.length; i < l; i++){
			if(data[i][idProperty] == id){
				data.splice(i, 1);
				return;
			}
		}
	},
	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.api.Store.QueryOptions?
		//		The optional arguments to apply to the resultset.
		//	returns: dojo.store.api.Store.QueryResults
		//		The results of the query, extended with iterative methods.
		//
		// 	example:
		// 		Given the following store:
		//
		// 	|	var store = new dojo.store.Memory({
		// 	|		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 });
		return dojo.store.util.QueryResults(this.queryEngine(query, options)(this.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;
		}else{
			this.data = data;
		}

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

}