/*
* Copyright 2003-2006, 2009, 2017, United States Government, as represented by the Administrator of the
* National Aeronautics and Space Administration. All rights reserved.
*
* The NASAWorldWind/WebWorldWind platform is licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
define([
'./KmlAttribute',
'./KmlElementsFactory',
'./KmlTreeKeyValueCache',
'../../../util/WWUtil'
], function (
Attribute,
KmlElementsFactory,
TreeKeyValueCache,
WWUtil
) {
"use strict";
/**
* More complex factory, which retrieves the values from cache and in case the value isn't present there it
* stores the value in cache.
* @constructor
* @alias KmlElementsFactoryCached
*/
var KmlElementsFactoryCached = function(options) {
this.internalFactory = new KmlElementsFactory(options);
this.cache = TreeKeyValueCache.applicationLevelCache();
};
/**
* It adds caching functionality on top of the KmlElementsFactory all method.
* @param element {KmlObject} Element whose children are considered
* @returns {KmlObject[]} All objects among the elements children
* @see KmlElementsFactory.prototype.all
*/
KmlElementsFactoryCached.prototype.all = function(element){
var parentNode = element.node;
var children = this.cache.level(this.cacheKey(element.node, "All"));
if (children) {
var results = [];
for(var key in children) {
if(children.hasOwnProperty(key)) {
results.push(children[key]);
}
}
return results;
}
var elements = this.internalFactory.all(element);
if(elements && elements.length) {
var self = this;
elements.forEach(function (pElement) {
self.cache.add(self.cacheKey(parentNode, "All"), self.cacheKey(pElement.node), pElement);
});
}
return elements;
};
/**
* It adds caching functionality on top of the KmlElementsFactory specific method.
* @param element {KmlObject} Element whose children are considered
* @param options {Object}
* @param options.name {String} Name of the element to retrieve from the element
* @param options.transformer {Function} Function returning correct value. It accepts the node and returns value.
* This mechanism can be used for the attributes as well.
* @returns Relevant value.
* @see KmlElementsFactory.prototype.specific
*/
KmlElementsFactoryCached.prototype.specific = function(element, options){
var parentNode = element.node;
var name = options.name;
if(options.attribute) {
name = options.attribute + name;
}
var child = this.cache.value(this.cacheKey(parentNode), name);
if (child) {
return child;
}
var result = this.internalFactory.specific(element, options);
if(result && result.node) {
this.cache.add(this.cacheKey(parentNode), this.cacheKey(result.node), result);
} else if(result) {
this.cache.add(this.cacheKey(parentNode), name, result);
}
return result;
};
/**
* It adds caching functionality on top of the KmlElementsFactory any method.
* @param element {KmlObject} Element whose children are considered
* @param options {Object}
* @param options.name {String[]} Array of the names among which should be the one we are looking for.
* @returns {KmlObject|null} KmlObject if there is one with the passed in name.
* @see KmlElementsFactory.prototype.any
*/
KmlElementsFactoryCached.prototype.any = function(element, options){
var parentNode = element.node;
var self = this;
var child = null;
var potentialChild;
options.name.forEach(function(name){
potentialChild = self.cache.value(self.cacheKey(parentNode), name);
if(potentialChild) {
child = potentialChild;
}
});
if (child) {
return child;
}
var result = this.internalFactory.any(element, options);
if(result) {
this.cache.add(self.cacheKey(parentNode), self.cacheKey(result.node), result);
}
return result;
};
/**
* It creates cache key based on the node. In case the node doesn't have any id, it also creates id for this
* element. This id is used for storing the value in the cache.
* @param node {Node} Node for which generate the key.
* @param prefix {String|undefined} Prefix for the level
* @returns {String} Value representing the key.
*/
KmlElementsFactoryCached.prototype.cacheKey = function(node, prefix) {
var idAttribute = new Attribute(node, "id");
if (!idAttribute.exists()) {
idAttribute.save(WWUtil.guid());
}
var result = node.nodeName + "#" + idAttribute.value();
if(prefix) {
result = prefix + result;
}
return result;
};
var applicationWide = new KmlElementsFactoryCached();
/**
* It returns application wide instance of the factory.
* @returns {KmlElementsFactoryCached} Singleton instance of factory for Application.
*/
KmlElementsFactoryCached.applicationWide = function(){
return applicationWide;
};
return KmlElementsFactoryCached;
});