File: datasource/js/datasource-cache.js

            /**
             * Plugs DataSource with caching functionality.
             *
             * @module datasource
             * @submodule datasource-cache
             */
            
            /**
             * DataSourceCache extension binds Cache to DataSource.
             * @class DataSourceCacheExtension
             */
            var DataSourceCacheExtension = function() {
            };
            
            Y.mix(DataSourceCacheExtension, {
                /**
                 * The namespace for the plugin. This will be the property on the host which
                 * references the plugin instance.
                 *
                 * @property NS
                 * @type String
                 * @static
                 * @final
                 * @value "cache"
                 */
                NS: "cache",
            
                /**
                 * Class name.
                 *
                 * @property NAME
                 * @type String
                 * @static
                 * @final
                 * @value "dataSourceCacheExtension"
                 */
                NAME: "dataSourceCacheExtension"
            });
            
            DataSourceCacheExtension.prototype = {
                /**
                * Internal init() handler.
                *
                * @method initializer
                * @param config {Object} Config object.
                * @private
                */
                initializer: function(config) {
                    this.doBefore("_defRequestFn", this._beforeDefRequestFn);
                    this.doBefore("_defResponseFn", this._beforeDefResponseFn);
                },
            
                /**
                 * First look for cached response, then send request to live data.
                 *
                 * @method _beforeDefRequestFn
                 * @param e {EventFacade} Event Facade with the following properties:
                 * <dl>
                 * <dt>tId (Number)</dt> <dd>Unique transaction ID.</dd>
                 * <dt>request (Object)</dt> <dd>The request.</dd>
                 * <dt>callback (Object)</dt> <dd>The callback object.</dd>
                 * <dt>cfg (Object)</dt> <dd>Configuration object.</dd>
                 * </dl>
                 * @protected
                 */
                _beforeDefRequestFn: function(e) {
                    // Is response already in the Cache?
                    var entry = (this.retrieve(e.request)) || null,
                        payload = e.details[0];
            
                    if (entry && entry.response) {
                        payload.cached   = entry.cached;
                        payload.response = entry.response;
                        payload.data     = entry.data;
            
                        this.get("host").fire("response", payload);
            
                        return new Y.Do.Halt("DataSourceCache extension halted _defRequestFn");
                    }
                },
            
                /**
                 * Adds data to cache before returning data.
                 *
                 * @method _beforeDefResponseFn
                 * @param e {EventFacade} Event Facade with the following properties:
                 * <dl>
                 * <dt>tId (Number)</dt> <dd>Unique transaction ID.</dd>
                 * <dt>request (Object)</dt> <dd>The request.</dd>
                 * <dt>callback (Object)</dt> <dd>The callback object with the following properties:
                 *     <dl>
                 *         <dt>success (Function)</dt> <dd>Success handler.</dd>
                 *         <dt>failure (Function)</dt> <dd>Failure handler.</dd>
                 *     </dl>
                 * </dd>
                 * <dt>data (Object)</dt> <dd>Raw data.</dd>
                 * <dt>response (Object)</dt> <dd>Normalized response object with the following properties:
                 *     <dl>
                 *         <dt>cached (Object)</dt> <dd>True when response is cached.</dd>
                 *         <dt>results (Object)</dt> <dd>Parsed results.</dd>
                 *         <dt>meta (Object)</dt> <dd>Parsed meta data.</dd>
                 *         <dt>error (Object)</dt> <dd>Error object.</dd>
                 *     </dl>
                 * </dd>
                 * <dt>cfg (Object)</dt> <dd>Configuration object.</dd>
                 * </dl>
                 * @protected
                 */
                 _beforeDefResponseFn: function(e) {
                    // Add to Cache before returning
                    if(e.response && !e.cached) {
                        this.add(e.request, e.response);
                    }
                 }
            };
            
            Y.namespace("Plugin").DataSourceCacheExtension = DataSourceCacheExtension;
            
            
            
            /**
             * DataSource plugin adds cache functionality.
             * @class DataSourceCache
             * @extends Cache
             * @uses Plugin.Base, DataSourceCachePlugin
             */
            function DataSourceCache(config) {
                var cache = config && config.cache ? config.cache : Y.Cache,
                    tmpclass = Y.Base.create("dataSourceCache", cache, [Y.Plugin.Base, Y.Plugin.DataSourceCacheExtension]),
                    tmpinstance = new tmpclass(config);
                tmpclass.NS = "tmpClass";
                return tmpinstance;
            }
            
            Y.mix(DataSourceCache, {
                /**
                 * The namespace for the plugin. This will be the property on the host which
                 * references the plugin instance.
                 *
                 * @property NS
                 * @type String
                 * @static
                 * @final
                 * @value "cache"
                 */
                NS: "cache",
            
                /**
                 * Class name.
                 *
                 * @property NAME
                 * @type String
                 * @static
                 * @final
                 * @value "dataSourceCache"
                 */
                NAME: "dataSourceCache"
            });
            
            
            Y.namespace("Plugin").DataSourceCache = DataSourceCache;