The source code

    /*!
     * Ext JS Library 3.4.0
     * Copyright(c) 2006-2011 Sencha Inc.
     * licensing@sencha.com
     * http://www.sencha.com/license
     */
    /**
     * @class Ext.data.DirectStore
     * @extends Ext.data.Store
     * Small helper class to create an {@link Ext.data.Store} configured with an
     * {@link Ext.data.DirectProxy} and {@link Ext.data.JsonReader} to make interacting
     * with an {@link Ext.Direct} Server-side {@link Ext.direct.Provider Provider} easier.
     * To create a different proxy/reader combination create a basic {@link Ext.data.Store}
     * configured as needed.
     *
     * *Note: Although they are not listed, this class inherits all of the config options of:
     *
     * {@link Ext.data.Store Store}
     *
     *
     *
     * {@link Ext.data.JsonReader JsonReader}
     *
     * {@link Ext.data.JsonReader#root root}
     * {@link Ext.data.JsonReader#idProperty idProperty}
     * {@link Ext.data.JsonReader#totalProperty totalProperty}
     *
     *
     * {@link Ext.data.DirectProxy DirectProxy}
     *
     * {@link Ext.data.DirectProxy#directFn directFn}
     * {@link Ext.data.DirectProxy#paramOrder paramOrder}
     * {@link Ext.data.DirectProxy#paramsAsHash paramsAsHash}
     *
     *
     *
     * @xtype directstore
     *
     * @constructor
     * @param {Object} config
     */
    Ext.data.DirectStore = Ext.extend(Ext.data.Store, {
        constructor : function(config){
            // each transaction upon a singe record will generate a distinct Direct transaction since Direct queues them into one Ajax request.
            var c = Ext.apply({}, {
                batchTransactions: false
            }, config);
            Ext.data.DirectStore.superclass.constructor.call(this, Ext.apply(c, {
                proxy: Ext.isDefined(c.proxy) ? c.proxy : new Ext.data.DirectProxy(Ext.copyTo({}, c, 'paramOrder,paramsAsHash,directFn,api')),
                reader: (!Ext.isDefined(c.reader) && c.fields) ? new Ext.data.JsonReader(Ext.copyTo({}, c, 'totalProperty,root,idProperty'), c.fields) : c.reader
            }));
        }
    });
    Ext.reg('directstore', Ext.data.DirectStore);