File: datasource/js/datasource-io.js

            /**
             * 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
                    },
            
                    /**
                     * Default IO Config.
                     *
                     * @attribute ioConfig
                     * @type Object
                     * @default null
                     */
                     ioConfig: {
                        value: null
                     }
                }
            });
            
            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:[]};
                },
            
                /**
                * IO success callback.
                *
                * @method successHandler
                * @param id {String} Transaction ID.
                * @param response {String} Response.
                * @param e {EventFacade} Event facade.
                * @private
                */
                successHandler: function (id, response, e) {
                    var defIOConfig = this.get("ioConfig"),
                        payload = e.details[0];
            
                    delete Y.DataSource.Local.transactions[e.tId];
            
                    payload.data = response;
                    this.fire("data", payload);
            
                    Y.log("Received IO data response for \"" + e.request + "\"", "info", "datasource-io");
            
                    if (defIOConfig && defIOConfig.on && defIOConfig.on.success) {
                        defIOConfig.on.success.apply(defIOConfig.context || Y, arguments);
                    }
                },
            
                /**
                * IO failure callback.
                *
                * @method failureHandler
                * @param id {String} Transaction ID.
                * @param response {String} Response.
                * @param e {EventFacade} Event facade.
                * @private
                */
                failureHandler: function (id, response, e) {
                    var defIOConfig = this.get("ioConfig"),
                        payload = e.details[0];
            
                    delete Y.DataSource.Local.transactions[e.tId];
            
                    payload.error = new Error("IO data failure");
                    Y.log("IO data failure", "error", "datasource-io");
            
                    payload.data = response;
                    this.fire("data", payload);
            
                    Y.log("Received IO data failure for \"" + e.request + "\"", "info", "datasource-io");
            
                    if (defIOConfig && defIOConfig.on && defIOConfig.on.failure) {
                        defIOConfig.on.failure.apply(defIOConfig.context || Y, arguments);
                    }
                },
            
                /**
                * @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 {EventFacade} 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"),
                        io = this.get("io"),
                        defIOConfig = this.get("ioConfig"),
                        request = e.request,
                        cfg = Y.merge(defIOConfig, e.cfg, {
                            on: Y.merge(defIOConfig, {
                                success: this.successHandler,
                                failure: this.failureHandler
                            }),
                            context: this,
                            "arguments": e
                        });
            
                    // Support for POST transactions
                    if(Y.Lang.isString(request)) {
                        if(cfg.method && (cfg.method.toUpperCase() === "POST")) {
                            cfg.data = cfg.data ? cfg.data+request : request;
                        }
                        else {
                            uri += request;
                        }
                    }
                    Y.DataSource.Local.transactions[e.tId] = io(uri, cfg);
                    return e.tId;
                }
            });
            
            Y.DataSource.IO = DSIO;