/*

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-function', function(Y) {

/**

 * Provides a DataSource implementation which can be used to retrieve data from a custom function.

 *

 * @module datasource

 * @submodule datasource-function

 */

/**

 * Function subclass for the DataSource Utility.

 * @class DataSource.Function

 * @extends DataSource.Local

 * @constructor

 */    

var LANG = Y.Lang,

    DSFn = function() {

        DSFn.superclass.constructor.apply(this, arguments);

    };

    /////////////////////////////////////////////////////////////////////////////

    //

    // DataSource.Function static properties

    //

    /////////////////////////////////////////////////////////////////////////////

Y.mix(DSFn, {

    /**

     * Class name.

     *

     * @property NAME

     * @type String

     * @static     

     * @final

     * @value "dataSourceFunction"

     */

    NAME: "dataSourceFunction",

    /////////////////////////////////////////////////////////////////////////////

    //

    // DataSource.Function Attributes

    //

    /////////////////////////////////////////////////////////////////////////////

    ATTRS: {

        /**

        * @attribute source

        * @description Pointer to live data.

        * @type MIXED

        * @default null

        */

        source: {

            validator: LANG.isFunction

        }

    }

});

Y.extend(DSFn, Y.DataSource.Local, {

    /**

     * Passes query string to IO. 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 fn = this.get("source"),

            response;

            if(fn) {

                response = fn(e.request, this, e);

                this.fire("data", Y.mix({data:response}, e));

            }

            else {

                e.error = new Error("Function data failure");

                this.fire("error", e);

            }

        return e.tId;

    }

});

Y.DataSource.Function = DSFn;

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