/**
+ * Provides a DataSource implementation which can be used to retrieve data via the Get Utility.
+ *
+ * @module datasource
+ * @submodule datasource-get
+ */
+
+/**
+ * Get Utility subclass for the DataSource Utility.
+ * @class DataSource.Get
+ * @extends DataSource.Local
+ * @constructor
+ */
+var DSGet = function() {
+ DSGet.superclass.constructor.apply(this, arguments);
+};
+
+
+ /////////////////////////////////////////////////////////////////////////////
+ //
+ // DataSource.Get static properties
+ //
+ /////////////////////////////////////////////////////////////////////////////
+Y.mix(DSGet, {
+ /**
+ * Class name.
+ *
+ * @property NAME
+ * @type String
+ * @static
+ * @final
+ * @value "dataSourceGet"
+ */
+ NAME: "dataSourceGet",
+
+
+ /////////////////////////////////////////////////////////////////////////////
+ //
+ // DataSource.Get Attributes
+ //
+ /////////////////////////////////////////////////////////////////////////////
+
+ ATTRS: {
+ /**
+ * Pointer to Get Utility.
+ *
+ * @attribute get
+ * @type Y.Get
+ * @default Y.Get
+ */
+ get: {
+ value: Y.Get,
+ cloneDefaultValue: false
+ },
+
+/**
+ * Defines request/response management in the following manner:
+ * <dl>
+ * <!--<dt>queueRequests</dt>
+ * <dd>If a request is already in progress, wait until response is returned before sending the next request.</dd>
+ * <dt>cancelStaleRequests</dt>
+ * <dd>If a request is already in progress, cancel it before sending the next request.</dd>-->
+ * <dt>ignoreStaleResponses</dt>
+ * <dd>Send all requests, but handle only the response for the most recently sent request.</dd>
+ * <dt>allowAll</dt>
+ * <dd>Send all requests and handle all responses.</dd>
+ * </dl>
+ *
+ * @attribute asyncMode
+ * @type String
+ * @default "allowAll"
+ */
+asyncMode: {
+ value: "allowAll"
+},
+
+/**
+ * Callback string parameter name sent to the remote script. By default,
+ * requests are sent to
+ * <URI>?<scriptCallbackParam>=callbackFunction
+ *
+ * @attribute scriptCallbackParam
+ * @type String
+ * @default "callback"
+ */
+scriptCallbackParam : {
+ value: "callback"
+},
+
+/**
+ * Accepts the DataSource instance and a callback ID, and returns a callback
+ * param/value string that gets appended to the script URI. Implementers
+ * can customize this string to match their server's query syntax.
+ *
+ * @attribute generateRequestCallback
+ * @type Function
+ */
+generateRequestCallback : {
+ value: function(self, id) {
+ return "&" + self.get("scriptCallbackParam") + "=YUI.Env.DataSource.callbacks["+id+"]" ;
+ }
+}
+
+
+
+
+
+ },
+
+ /**
+ * Global array of callback functions, one for each request sent.
+ *
+ * @property callbacks
+ * @type Function[]
+ * @static
+ */
+ callbacks : [],
+
+ /**
+ * Unique ID to track requests.
+ *
+ * @property _tId
+ * @type Number
+ * @private
+ * @static
+ */
+ _tId : 0
+});
+
+Y.extend(DSGet, Y.DataSource.Local, {
+ /**
+ * Passes query string to Get Utility. Fires <code>response</code> event when
+ * response is received asynchronously.
+ *
+ * @method _defRequestFn
+ * @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>
+ * </dl>
+ * </dd>
+ * <dt>cfg (Object)</dt> <dd>Configuration object.</dd>
+ * </dl>
+ * @protected
+ */
+ _defRequestFn: function(e) {
+ var uri = this.get("source"),
+ get = this.get("get"),
+ id = DSGet._tId++,
+ self = this;
+
+
+
+
+
+
+
+
+
+
+
+
+
+ // Dynamically add handler function with a closure to the callback stack
+ YUI.Env.DataSource.callbacks[id] = Y.rbind(function(response) {
+ if((self.get("asyncMode") !== "ignoreStaleResponses")||
+ (id === DSGet.callbacks.length-1)) { // Must ignore stale responses
+
+ self.fire("data", Y.mix({data:response}, e));
+ }
+ else {
+ Y.log("DataSource ignored stale response for id " + e.tId + "(" + e.request + ")", "info", "datasource-get");
+ }
+
+ delete DSGet.callbacks[id];
+ }, this, id);
+
+ // We are now creating a request
+ uri += e.request + this.get("generateRequestCallback")(this, id);
+ //uri = this.doBefore(sUri);
+ Y.log("DataSource is querying URL " + uri, "info", "datasource-get");
+ get.script(uri, {
+ autopurge: true,
+ // Works in Firefox only....
+ onFailure: Y.bind(function(e) {
+ e.error = new Error("Script node data failure");
+ this.fire("error", e);
+ }, this, e)
+ });
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ return e.tId;
+ }
+});
+
+Y.DataSource.Get = DSGet;
+YUI.namespace("Env.DataSource.callbacks");
+
+