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   1  /*
   2  YUI 3.17.2 (build 9c3c78e)
   3  Copyright 2014 Yahoo! Inc. All rights reserved.
   4  Licensed under the BSD License.
   5  http://yuilibrary.com/license/
   6  */
   7  
   8  YUI.add('datasource-get', function (Y, NAME) {
   9  
  10  /**
  11   * Provides a DataSource implementation which can be used to retrieve data via the Get Utility.
  12   *
  13   * @module datasource
  14   * @submodule datasource-get
  15   */
  16  
  17  /**
  18   * Get Utility subclass for the DataSource Utility.
  19   * @class DataSource.Get
  20   * @extends DataSource.Local
  21   * @constructor
  22   */
  23  var DSGet = function() {
  24      DSGet.superclass.constructor.apply(this, arguments);
  25  };
  26  
  27  
  28  Y.DataSource.Get = Y.extend(DSGet, Y.DataSource.Local, {
  29      /**
  30       * Passes query string to Get Utility. Fires <code>response</code> event when
  31       * response is received asynchronously.
  32       *
  33       * @method _defRequestFn
  34       * @param e {EventFacade} Event Facade with the following properties:
  35       * <dl>
  36       * <dt>tId (Number)</dt> <dd>Unique transaction ID.</dd>
  37       * <dt>request (Object)</dt> <dd>The request.</dd>
  38       * <dt>callback (Object)</dt> <dd>The callback object with the following properties:
  39       *     <dl>
  40       *         <dt>success (Function)</dt> <dd>Success handler.</dd>
  41       *         <dt>failure (Function)</dt> <dd>Failure handler.</dd>
  42       *     </dl>
  43       * </dd>
  44       * <dt>cfg (Object)</dt> <dd>Configuration object.</dd>
  45       * </dl>
  46       * @protected
  47       */
  48      _defRequestFn: function(e) {
  49          var uri  = this.get("source"),
  50              get  = this.get("get"),
  51              guid = Y.guid().replace(/\-/g, '_'),
  52              generateRequest = this.get( "generateRequestCallback" ),
  53              payload = e.details[0],
  54              self = this;
  55  
  56          /**
  57           * Stores the most recent request id for validation against stale
  58           * response handling.
  59           *
  60           * @property _last
  61           * @type {String}
  62           * @protected
  63           */
  64          this._last = guid;
  65  
  66          // Dynamically add handler function with a closure to the callback stack
  67          // for access to guid
  68          YUI.Env.DataSource.callbacks[guid] = function(response) {
  69              delete YUI.Env.DataSource.callbacks[guid];
  70              delete Y.DataSource.Local.transactions[e.tId];
  71  
  72              var process = self.get('asyncMode') !== "ignoreStaleResponses" ||
  73                            self._last === guid;
  74  
  75              if (process) {
  76                  payload.data = response;
  77  
  78                  self.fire("data", payload);
  79              } else {
  80                  Y.log("DataSource ignored stale response for id " + e.tId + "(" + e.request + ")", "info", "datasource-get");
  81              }
  82  
  83          };
  84  
  85          // Add the callback param to the request url
  86          uri += e.request + generateRequest.call( this, guid );
  87  
  88          Y.log("DataSource is querying URL " + uri, "info", "datasource-get");
  89  
  90          Y.DataSource.Local.transactions[e.tId] = get.script(uri, {
  91              autopurge: true,
  92              // Works in Firefox only....
  93              onFailure: function (o) {
  94                  delete YUI.Env.DataSource.callbacks[guid];
  95                  delete Y.DataSource.Local.transactions[e.tId];
  96  
  97                  payload.error = new Error(o.msg || "Script node data failure");
  98  
  99                  Y.log("Script node data failure", "error", "datasource-get");
 100  
 101                  self.fire("data", payload);
 102              },
 103              onTimeout: function(o) {
 104                  delete YUI.Env.DataSource.callbacks[guid];
 105                  delete Y.DataSource.Local.transactions[e.tId];
 106  
 107                  payload.error = new Error(o.msg || "Script node data timeout");
 108  
 109                  Y.log("Script node data timeout", "error", "datasource-get");
 110  
 111                  self.fire("data", payload);
 112              }
 113          });
 114  
 115          return e.tId;
 116      },
 117  
 118  
 119      /**
 120       * Default method for adding callback param to url.  See
 121       * generateRequestCallback attribute.
 122       *
 123       * @method _generateRequest
 124       * @param guid {String} unique identifier for callback function wrapper
 125       * @protected
 126       */
 127       _generateRequest: function (guid) {
 128          return "&" + this.get("scriptCallbackParam") +
 129                  "=YUI.Env.DataSource.callbacks." + guid;
 130      }
 131  
 132  }, {
 133  
 134      /**
 135       * Class name.
 136       *
 137       * @property NAME
 138       * @type String
 139       * @static
 140       * @final
 141       * @value "dataSourceGet"
 142       */
 143      NAME: "dataSourceGet",
 144  
 145  
 146      ////////////////////////////////////////////////////////////////////////////
 147      //
 148      // DataSource.Get Attributes
 149      //
 150      ////////////////////////////////////////////////////////////////////////////
 151      ATTRS: {
 152          /**
 153           * Pointer to Get Utility.
 154           *
 155           * @attribute get
 156           * @type Y.Get
 157           * @default Y.Get
 158           */
 159          get: {
 160              value: Y.Get,
 161              cloneDefaultValue: false
 162          },
 163  
 164          /**
 165           * Defines request/response management in the following manner:
 166           * <dl>
 167           *     <!--<dt>queueRequests</dt>
 168           *     <dd>If a request is already in progress, wait until response is
 169           *     returned before sending the next request.</dd>
 170           *     <dt>cancelStaleRequests</dt>
 171           *     <dd>If a request is already in progress, cancel it before
 172           *     sending the next request.</dd>-->
 173           *     <dt>ignoreStaleResponses</dt>
 174           *     <dd>Send all requests, but handle only the response for the most
 175           *     recently sent request.</dd>
 176           *     <dt>allowAll</dt>
 177           *     <dd>Send all requests and handle all responses.</dd>
 178           * </dl>
 179           *
 180           * @attribute asyncMode
 181           * @type String
 182           * @default "allowAll"
 183           */
 184          asyncMode: {
 185              value: "allowAll"
 186          },
 187  
 188          /**
 189           * Callback string parameter name sent to the remote script. By default,
 190           * requests are sent to
 191           * &#60;URI&#62;?&#60;scriptCallbackParam&#62;=callbackFunction
 192           *
 193           * @attribute scriptCallbackParam
 194           * @type String
 195           * @default "callback"
 196           */
 197          scriptCallbackParam : {
 198              value: "callback"
 199          },
 200  
 201          /**
 202           * Accepts the DataSource instance and a callback ID, and returns a callback
 203           * param/value string that gets appended to the script URI. Implementers
 204           * can customize this string to match their server's query syntax.
 205           *
 206           * @attribute generateRequestCallback
 207           * @type Function
 208           */
 209          generateRequestCallback : {
 210              value: function () {
 211                  return this._generateRequest.apply(this, arguments);
 212              }
 213          }
 214      }
 215  });
 216  
 217  YUI.namespace("Env.DataSource.callbacks");
 218  
 219  
 220  }, '3.17.2', {"requires": ["datasource-local", "get"]});