Sencha removed the refreshFn from the pullrefresh plugin in ST 2.2. Here is an user extension with gives the old functionality back to you.

/** * This user extension gives st 2.3.0 Pullrefresh the RefreshFn back * based on sencha touch 2.3.0 *  * @class Ext.ux.touch.PullRefreshFn * @version 2.0.1-beta * @author Martin Hess 
     
       * * ## Example * *     Ext.create('Ext.dataview.List', { *         fullscreen: true, * *         store: store, * *         plugins: [ *             { *                 xclass: 'Ext.ux.touch.PullRefreshFn', *                 pullRefreshText: 'Pull down for more new Tweets!' *                 refreshFn: function() {  *                        Ext.getStore('ENTER YOUR STORE HERE').load('',1) *                   } *             } *         ], * *         itemTpl: [ *             'YOUR ITEMTPL' *         ] *     }); */Ext.define('myapp.model.PullRefreshFn', {    extend: 'Ext.plugin.PullRefresh',    alias: 'plugin.pullrefreshfn',    requires: ['Ext.DateExtras'],    xtype:'refreshFn',    config: {        /**         * @cfg {Function} refreshFn The function that will be called to refresh the list.         * If this is not defined, the store's load function will be called.         * The refresh function gets called with a reference to this plugin instance.         * @accessor         */        refreshFn: null,        pullText: '下拉能够更新',		  lastUpdatedText:"上次刷新时间",		  lastUpdatedDateFormat:"Y-m-d H:i",		  releaseText:"松开開始更新",		  loadedText:"载入完毕"    },        fetchLatest: function() {        if (this.getRefreshFn()) {            this.getRefreshFn().call(this, this);            this.setState("loaded");            this.fireEvent('latestfetched', this, 'refreshFn, you have to handle toInsert youself');            if (this.getAutoSnapBack()) {                this.snapBack();            }        } else {                console.log('fetchLatest')            var store = this.getList().getStore(),                proxy = store.getProxy(),                operation;                operation = Ext.create('Ext.data.Operation', {                page: 1,                start: 0,                model: store.getModel(),                limit: store.getPageSize(),                action: 'read',                sorters: store.getSorters(),                filters: store.getRemoteFilter() ? store.getFilters() : []            });                proxy.read(operation, this.onLatestFetched, this);        }    },        /**     * Snaps the List back to the top after a pullrefresh is complete     * @param {Boolean=} force Force the snapback to occur regardless of state {optional}     */    snapBack: function(force) {        if(this.getState() !== "loaded" && force !== true) return;        var that = this,            list = this.getList(),            scroller = list.getScrollable().getScroller(),            currentY = scroller.minPosition.y;                    scroller.refresh();        scroller.minPosition.y = 0;                scroller.on({            scrollend: this.onSnapBackEnd,            single: true,            scope: this        });        this.setIsSnappingBack(true);                scroller.getTranslatable().translateAnimated(0, currentY, {duration: this.getSnappingAnimationDuration()});        setTimeout(            function () {                scroller.scrollTo(0,1);                scroller.scrollToTop();            },            that.getSnappingAnimationDuration()        );            }});