How to catch a widgetcolumn's data change event?

Hi.

I have a Grid with a widgetcolumn. This is the widget of the widgetcolumn:

Code:

Ext.define('TestPortal.view.portal.testlist.TestItem', {
    //extend: 'Ext.panel.Panel',
    extend: 'Ext.container.Container',

    xtype: 'app-testitem',

    controller: 'testitem',
    viewModel: {
        type: 'testitem'
    },

    layout: {
        type: 'vbox',
        align: 'stretch',
        pack: 'start'
    },
    
    //just to prevent a error
    defaultBindProperty: 'recordId',

    config: {
        recordId: '',
        setRecordId: function(value){
            this.refresh(false);
        }
    },
    
    height: 60,
    flex: 1,

    listeners: {
        boxready: function(){
            var me = this;
            me.refresh(true);
        }
    },

    refresh: function(noDelay){
        var me = this;
        var task = new Ext.util.DelayedTask(function(){
            var dataModel = me.getWidgetRecord();
            var viewModel = me.getViewModel();
            viewModel.setData({
                record: dataModel
            });
        });
        if(noDelay){
            task.delay(1);
        }else{
            task.delay(1000);
        }
    },

    items: [
        {
            xtype: 'label',
            bind: '{record.name}'
        },{
            xtype: 'label',
            bind: '{record.info}'
        },{
            xtype: 'label',
            bind: 'Ok: {successed}'
        }
    ]
});

The Problem is: I need to set the viewmodels data manually after reloading the grid's store. I trie'd to overwrite the defaultBindProperty's setter Method to catch a data change. But at this time the widgetrecord is still null.

Is there a way to catch a data changed in widgetcolumn or the widget itshelf? Or is there a way to access the widgets via the grid?