/*

Copyright (c) 2009, Yahoo! Inc. All rights reserved.

Code licensed under the BSD License:

http://developer.yahoo.net/yui/license.txt

version: 3.0.0b1

build: 1163

*/

YUI.add('datasource-polling', function(Y) {

/**

 * 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);

}, '3.0.0b1' ,{requires:['datasource-local']});