Extjs 表格分组 grid grouping

Ext.onReady(function(){Ext.QuickTips.init();  Ext.form.Field.prototype.msgTarget='side';var itemsPerPage=10;var store1=Ext.create('Ext.data.Store',{   storeId:'gridStore1',   fields:['Id','Title','Time','Author'],   pageSize: itemsPerPage,   autoLoad:true,   groupField:'Author',//制定grid分组的依据字段   data:{'items':[   {Id:'001',Title:'wwww',Time:'2012-8-8',Author:'张三'},   {Id:'002',Title:'wwww',Time:'2012-8-8',Author:'张三'},   {Id:'003',Title:'wwww',Time:'2012-8-8',Author:'李四'},   {Id:'004',Title:'wwww',Time:'2012-8-8',Author:'李四'},   {Id:'005',Title:'wwww',Time:'2012-8-8',Author:'李四'},   {Id:'006',Title:'wwww',Time:'2012-8-8',Author:'张三'},   ]},   proxy:{     type:'memory',     reader:{       type:'json',       root:'items',       totalProperty:'counts'     }}});//显示信息的grid    var gridPanel1=Ext.create('Ext.grid.Panel',{store:store1,    selType:'rowmodel',    renderTo:'content',    viewConfig:{       columnsText: '列',           sortAscText: '升序',           sortDescText: '降序'    },    features:[         Ext.create("Ext.grid.feature.Grouping",{         groupByText:'字段分组',         showGroupsText:'显示分组',         groupHeaderTpl:'作者：{name}({rows.length})',         startCollapsed:false                           })                                ],        columns:[    {header:'序号',dataIndex:'Id'},    {header:'标题',dataIndex:'Title',flex:1},    {header:'时间',dataIndex:'Time'},    {header:'时间',dataIndex:'Author'}    ],    bbar:Ext.create('Ext.toolbar.Paging', {    store:store1,            pageSize : 2,              emptyMsg : "没有数据显示！",   displayInfo : true,   displayMsg : '显示 {0} - {1} 共 {2} 条',   beforePageText : "页码 ",   afterPageText : "共 {0} 页",   firstText : "首页",   lastText : "末页",   nextText : "下一页",   prevText : "上一页",   refreshText : "刷新"          })});});

新增事件  groupclick，groupdbclick，groupcontextmenu，groupexpand，groupcollapse