API Docs for: 3.18.1
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File: datasource/js/datasource-cache.js

  1. /**
  2.  * Plugs DataSource with caching functionality.
  3.  *
  4.  * @module datasource
  5.  * @submodule datasource-cache
  6.  */
  7.  
  8. /**
  9.  * DataSourceCache extension binds Cache to DataSource.
  10.  * @class DataSourceCacheExtension
  11.  */
  12. var DataSourceCacheExtension = function() {
  13. };
  14.  
  15. Y.mix(DataSourceCacheExtension, {
  16.     /**
  17.      * The namespace for the plugin. This will be the property on the host which
  18.      * references the plugin instance.
  19.      *
  20.      * @property NS
  21.      * @type String
  22.      * @static
  23.      * @final
  24.      * @value "cache"
  25.      */
  26.     NS: "cache",
  27.  
  28.     /**
  29.      * Class name.
  30.      *
  31.      * @property NAME
  32.      * @type String
  33.      * @static
  34.      * @final
  35.      * @value "dataSourceCacheExtension"
  36.      */
  37.     NAME: "dataSourceCacheExtension"
  38. });
  39.  
  40. DataSourceCacheExtension.prototype = {
  41.     /**
  42.     * Internal init() handler.
  43.     *
  44.     * @method initializer
  45.     * @param config {Object} Config object.
  46.     * @private
  47.     */
  48.     initializer: function(config) {
  49.         this.doBefore("_defRequestFn", this._beforeDefRequestFn);
  50.         this.doBefore("_defResponseFn", this._beforeDefResponseFn);
  51.     },
  52.  
  53.     /**
  54.      * First look for cached response, then send request to live data.
  55.      *
  56.      * @method _beforeDefRequestFn
  57.      * @param e {EventFacade} Event Facade with the following properties:
  58.      * <dl>
  59.      * <dt>tId (Number)</dt> <dd>Unique transaction ID.</dd>
  60.      * <dt>request (Object)</dt> <dd>The request.</dd>
  61.      * <dt>callback (Object)</dt> <dd>The callback object.</dd>
  62.      * <dt>cfg (Object)</dt> <dd>Configuration object.</dd>
  63.      * </dl>
  64.      * @protected
  65.      */
  66.     _beforeDefRequestFn: function(e) {
  67.         // Is response already in the Cache?
  68.         var entry = (this.retrieve(e.request)) || null,
  69.             payload = e.details[0];
  70.  
  71.         if (entry && entry.response) {
  72.             payload.cached   = entry.cached;
  73.             payload.response = entry.response;
  74.             payload.data     = entry.data;
  75.  
  76.             this.get("host").fire("response", payload);
  77.  
  78.             return new Y.Do.Halt("DataSourceCache extension halted _defRequestFn");
  79.         }
  80.     },
  81.  
  82.     /**
  83.      * Adds data to cache before returning data.
  84.      *
  85.      * @method _beforeDefResponseFn
  86.      * @param e {EventFacade} Event Facade with the following properties:
  87.      * <dl>
  88.      * <dt>tId (Number)</dt> <dd>Unique transaction ID.</dd>
  89.      * <dt>request (Object)</dt> <dd>The request.</dd>
  90.      * <dt>callback (Object)</dt> <dd>The callback object with the following properties:
  91.      *     <dl>
  92.      *         <dt>success (Function)</dt> <dd>Success handler.</dd>
  93.      *         <dt>failure (Function)</dt> <dd>Failure handler.</dd>
  94.      *     </dl>
  95.      * </dd>
  96.      * <dt>data (Object)</dt> <dd>Raw data.</dd>
  97.      * <dt>response (Object)</dt> <dd>Normalized response object with the following properties:
  98.      *     <dl>
  99.      *         <dt>cached (Object)</dt> <dd>True when response is cached.</dd>
  100.      *         <dt>results (Object)</dt> <dd>Parsed results.</dd>
  101.      *         <dt>meta (Object)</dt> <dd>Parsed meta data.</dd>
  102.      *         <dt>error (Object)</dt> <dd>Error object.</dd>
  103.      *     </dl>
  104.      * </dd>
  105.      * <dt>cfg (Object)</dt> <dd>Configuration object.</dd>
  106.      * </dl>
  107.      * @protected
  108.      */
  109.      _beforeDefResponseFn: function(e) {
  110.         // Add to Cache before returning
  111.         if(e.response && !e.cached) {
  112.             this.add(e.request, e.response);
  113.         }
  114.      }
  115. };
  116.  
  117. Y.namespace("Plugin").DataSourceCacheExtension = DataSourceCacheExtension;
  118.  
  119.  
  120.  
  121. /**
  122.  * DataSource plugin adds cache functionality.
  123.  * @class DataSourceCache
  124.  * @extends Cache
  125.  * @uses Plugin.Base, DataSourceCachePlugin
  126.  */
  127. function DataSourceCache(config) {
  128.     var cache = config && config.cache ? config.cache : Y.Cache,
  129.         tmpclass = Y.Base.create("dataSourceCache", cache, [Y.Plugin.Base, Y.Plugin.DataSourceCacheExtension]),
  130.         tmpinstance = new tmpclass(config);
  131.     tmpclass.NS = "tmpClass";
  132.     return tmpinstance;
  133. }
  134.  
  135. Y.mix(DataSourceCache, {
  136.     /**
  137.      * The namespace for the plugin. This will be the property on the host which
  138.      * references the plugin instance.
  139.      *
  140.      * @property NS
  141.      * @type String
  142.      * @static
  143.      * @final
  144.      * @value "cache"
  145.      */
  146.     NS: "cache",
  147.  
  148.     /**
  149.      * Class name.
  150.      *
  151.      * @property NAME
  152.      * @type String
  153.      * @static
  154.      * @final
  155.      * @value "dataSourceCache"
  156.      */
  157.     NAME: "dataSourceCache"
  158. });
  159.  
  160.  
  161. Y.namespace("Plugin").DataSourceCache = DataSourceCache;
  162.  
  163.