datasource-cache.js revision 3ab1d84918e2599d8b7cae1fd6632c311c808774
/**
* Extends DataSource with caching functionality.
*
* @module datasource
* @submodule datasource-cache
*/
/**
* Adds cacheability to the YUI DataSource utility.
* @class DataSourceCache
* @extends Cache
*/
var DataSourceCache = function() {
DataSourceCache.superclass.constructor.apply(this, arguments);
};
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",
/////////////////////////////////////////////////////////////////////////////
//
// DataSourceCache Attributes
//
/////////////////////////////////////////////////////////////////////////////
ATTRS: {
}
});
Y.extend(DataSourceCache, Y.Cache, {
/**
* 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 {Event.Facade} 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>
* </dl>
* @protected
*/
_beforeDefRequestFn: function(e) {
// TODO: Remove temporary workaround for bug #2527838
e._yuifacade = false;
// Is response already in the Cache?
var entry = (this.retrieve(e.request)) || null;
if(entry && entry.response) {
this._owner.fire("response", Y.mix({response: entry.response}, e));
return new Y.Do.Halt("DataSourceCache plugin halted _defRequestFn");
}
},
/**
* Adds data to cache before returning data.
*
* @method _beforeDefResponseFn
* @param e {Event.Facade} 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>
* <dt>scope (Object)</dt> <dd>Execution context.</dd>
* </dl>
* </dd>
* <dt>data (Object)</dt> <dd>Raw data.</dd>
* <dt>response (Object)</dt> <dd>Normalized resopnse object with the following properties:
* <dl>
* <dt>results (Object)</dt> <dd>Parsed results.</dd>
* <dt>meta (Object)</dt> <dd>Parsed meta data.</dd>
* <dt>error (Boolean)</dt> <dd>Error flag.</dd>
* </dl>
* </dd>
* </dl>
* @protected
*/
_beforeDefResponseFn: function(e) {
// Add to Cache before returning
this.add(e.request, e.response, (e.callback && e.callback.argument));
}
});
Y.namespace('plugin');
Y.plugin.DataSourceCache = DataSourceCache;