Wijmo 5[Flex Grid Flex Grid Row Detail]

prevent flexgrid rowdetail collapse on sorting

HTML

<link rel="stylesheet" href="http://cdn.wijmo.com/5.latest/styles/wijmo.min.css">
<script src="http://cdn.wijmo.com/5.latest/controls/wijmo.min.js"></script>
<script src="http://cdn.wijmo.com/5.latest/controls/wijmo.grid.min.js"></script>
<script src="http://cdn.wijmo.com/5.latest/controls/wijmo.grid.detail.min.js"></script>
<script src="http://cdn.wijmo.com/5.latest/interop/angular/wijmo.angular.min.js"></script>
<div ng-app="app" ng-controller="appCtrl">
        <wj-flex-grid items-source="data" sorted-column="sortedColumn(s,e)" sorting-column="sortingColumn(s,e)">
            <wj-flex-grid-detail detail-visibility-mode="ExpandSingle" max-height="300" initialized="init(s,e)">
                <wj-flex-grid items-source="data"
                              headers-visibility="Column"
                              child-items-path="items" >
                    <wj-flex-grid-column binding="name" width="*"> </wj-flex-grid-column>
                    <wj-flex-grid-column binding="length" width="80" align="center"> </wj-flex-grid-column>
                </wj-flex-grid>
            </wj-flex-grid-detail>
        </wj-flex-grid>
    </div>

JavaScript

var countries = 'US,Germany,UK,Japan,Italy,Greece'.split(','),
            data = [];
        for (var i = 0; i < 10; i++) {
            data.push({
                id: i,
                country: countries[i % countries.length],
                date: new Date(2014, i % 12, i % 28),
                amount: Math.random() * 10000,
                active: i % 4 == 0
            });
        }
        var treeData = [ {
            name: '\u266B Adriane Simione',
            items: [ {
                name: '\u266A Intelligible Sky', 
                items: [
                    { name: 'Theories', length: '2:02' }, 
                    { name: 'Giant Eyes', length: '3:29' },
                    { name: 'Jovian Moons', length: '1:02' }, 
                    { name: 'Open Minds', length: '2:41' }, 
                    { name: 'Spacetronic Eyes', length: '3:41' }
                ] }
            ]},
            { name: '\u266B Amy Winehouse', 
                items: [
                    { name: '\u266A Back to Black', 
                        items: [
                            { name: 'Addicted', length: '1:34' },
                            { name: 'He Can Only Hold Her', length: '2:22' },
                            { name: 'Some Unholy War', length: '2:21' }, 
                            { name: 'Wake Up Alone', length: '3:43' }, 
                            { name: 'Tears Dry On Their Own', length: '1:25' }
                        ] }
                ]}];
        var app = angular.module('app', ['wj']);
        var isVisible = false;
        app.controller('appCtrl', function ($scope) {
            $scope.data = data;
            $scope.detailData = treeData;
            $scope.sortedColumn = function (s, e) {
                if(isVisible)
                    $scope.detail.showDetail(s.selection.row);
            };
            $scope.sortingColumn = function (s, e) {
                 isVisible=$scope.detail.isDetailVisible(s.selection.row);
            };
       ...