ExtJS RowExpander - nextBd is null - extjs4.1

Question

I have problem configuring RowExpander for my grid. When the grid renders the expander is already opened for each row and with nothing inside. When i click on its icon the following error is generated: nextBd is null. I found very similar problem here http://www.sencha.com/forum/showthread.php?185837-Grid-Panel-PlugIn-Rowexpander-nextBd-is-null but the solution does not work for me and still dont get it why plugin config cannot be passed in initComponent method:
Here is my grid code:
Ext.define('GSIP.view.plans.PlanReqList' ,{
extend: 'Ext.grid.Panel',
alias : 'widget.gsip_devplan_list',
id: 'gsip_plan_list',
plugins: [{
ptype: 'rowexpander',
rowBodyTpl : [
'Nazwa:{name}'
]
}],
//title:i18n.getMsg('gsip.view.PlanReqList.title'),
layout: 'fit',
initComponent: function() {
this.store = 'DevPlan';
// this.plugins = [{
// ptype: 'rowexpander',
// rowBodyTpl : [
// {name}
// ]
// }];
this.features = [{ftype:'filters', encode:false, local:true},{ftype:'grouping'}];
this.tbar = [{
xtype:'commandbutton',
id: 'newReq',
iconCls:'icon-application_add',
text: i18n.getMsg('gsip.view.plans.PlanReqList.addReq'),
command: 'newReq',
}];
this.viewConfig = {
forceFit:true,
getRowClass: function(record, index) {
var c = record.get('elapsedPercent');
if (c >= 0) {
return 'elapsed-normal';
}
}
}
this.columns = [
{header: "Id", dataIndex: "id", width:50, sortable: true, filter:{type:'numeric'}},
{header: i18n.getMsg('gsip.view.plans.PlanReqList.column.name'), dataIndex: "name", flex:1, sortable: true, filter:{type:'string'} },
}
];
this.callParent(arguments);
},

Answer 1

The rowexpander plugin makes use of a feature called rowbody.
In your initComponent() you override this.features (which already includes rowbody) with this line:
this.features = [{ftype:'filters', encode:false, local:true},{ftype:'grouping'}];
Thus the rowbody feature is not included; thus the .x-grid-rowbody-tr class is not injected; thus rowexpander can't find such class for nextBd and returns null.
You should try:
var iNewFeatures = [{ftype:'filters', encode:false, local:true},{ftype:'grouping'}];
this.features = iNewFeatures.concat( this.features );
Lastly, plugins cannot be initiated in InitComponent(), you can either declare them as configs, or within the constructor. See this thread for more info.