/**
+ * Extends DataSource with polling functionality.
+ *
+ * @module datasource
+ * @submodule datasource-polling
+ */
+
+/**
+ * Adds polling to the DataSource Utility.
+ * @class Pollable
+ * @extends DataSource.Local
+ */
+var LANG = Y.Lang,
+
+ Pollable = function() {
+ this._intervals = {};
+ };
+
+Pollable.prototype = {
+
+ /**
+ * @property _intervals
+ * @description Hash of polling interval IDs that have been enabled,
+ * stored here to be able to clear all intervals.
+ * @private
+ */
+ _intervals: null,
+
+ /**
+ * Sets up a polling mechanism to send requests at set intervals and forward
+ * responses to given callback.
+ *
+ * @method setInterval
+ * @param msec {Number} Length of interval in milliseconds.
+ * @param request {Object} Request object.
+ * @param callback {Object} An object literal with the following properties:
+ * <dl>
+ * <dt><code>success</code></dt>
+ * <dd>The function to call when the data is ready.</dd>
+ * <dt><code>failure</code></dt>
+ * <dd>The function to call upon a response failure condition.</dd>
+ * <dt><code>argument</code></dt>
+ * <dd>Arbitrary data that will be passed back to the success and failure handlers.</dd>
+ * </dl>
+ * @return {Number} Interval ID.
+ */
+ setInterval: function(msec, request, callback) {
+ var x = Y.later(msec, this, this.sendRequest, [request, callback], true);
+ this._intervals[x.id] = x;
+ return x.id;
+ },
+
+ /**
+ * Disables polling mechanism associated with the given interval ID.
+ *
+ * @method clearInterval
+ * @param id {Number} Interval ID.
+ */
+ clearInterval: function(id, key) {
+ // In case of being called by clearAllIntervals()
+ id = key || id;
+ if(this._intervals[id]) {
+ // Clear the interval
+ this._intervals[id].cancel();
+ // Clear from tracker
+ delete this._intervals[id];
+ }
+ },
+
+ /**
+ * Clears all intervals.
+ *
+ * @method clearAllIntervals
+ */
+ clearAllIntervals: function() {
+ Y.each(this._intervals, this.clearInterval, this);
+ }
+};
+
+Y.augment(Y.DataSource.Local, Pollable);
+