/*

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-io', function(Y) {

/**

 * Provides a DataSource implementation which can be used to retrieve data via the IO Utility.

 *

 * @module datasource

 * @submodule datasource-io

 */

/**

 * IO subclass for the DataSource Utility.

 * @class DataSource.IO

 * @extends DataSource.Local

 * @constructor

 */    

var DSIO = function() {

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

};

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

    //

    // DataSource.IO static properties

    //

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

Y.mix(DSIO, {

    /**

     * Class name.

     *

     * @property NAME

     * @type String

     * @static     

     * @final

     * @value "dataSourceIO"

     */

    NAME: "dataSourceIO",

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

    //

    // DataSource.IO Attributes

    //

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

    ATTRS: {

        /**

         * Pointer to IO Utility.

         *

         * @attribute io

         * @type Y.io

         * @default Y.io

         */

        io: {

            value: Y.io,

            cloneDefaultValue: false

        }

    }

});

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

    /**

    * Internal init() handler.

    *

    * @method initializer

    * @param config {Object} Config object.

    * @private

    */

    initializer: function(config) {

        this._queue = {interval:null, conn:null, requests:[]};

    },

    /**

    * @property _queue

    * @description Object literal to manage asynchronous request/response

    * cycles enabled if queue needs to be managed (asyncMode/ioConnMode):

    * <dl>

    *     <dt>interval {Number}</dt>

    *         <dd>Interval ID of in-progress queue.</dd>

    *     <dt>conn</dt>

    *         <dd>In-progress connection identifier (if applicable).</dd>

    *     <dt>requests {Object[]}</dt>

    *         <dd>Array of queued request objects: {request:request, callback:callback}.</dd>

    * </dl>

    * @type Object

    * @default {interval:null, conn:null, requests:[]}

    * @private

    */

    _queue: null,

    /**

     * 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 uri = this.get("source"),

            cfg = Y.mix(e.cfg, {

                on: {

                    success: function (id, response, e) {

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

                        Y.log("Received IO data response for \"" + e.request + "\"", "info", "datasource-io");

                    },

                    failure: function (id, response, e) {

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

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

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

                        Y.log("Received IO data failure for \"" + e.request + "\"", "info", "datasource-io");

                    }

                },

                context: this,

                arguments: e

            });

        this.get("io")(uri, cfg);

        return e.tId;

    }

});

Y.DataSource.IO = DSIO;

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