</div>
<div class="panel-body">
<div class="cf nestable-lists">
<div class="col-lg-6" >
<?php
echo Collapse::widget(['items' => $items]);
?>
</div>
<div class="col-lg-6 nestable-structure dd" id="<?php
echo $widget_id;
?>
">
<?php
$itemsData = yii\helpers\Json::decode($model->{$attribute});
?>
<?php
echo MenuBuilder::renderList($itemsData);
?>
</div>
</div>
</div>
<div class="panel-footer" style="display: none">
<?php
echo Html::activeTextarea($model, $attribute, ['cols' => 100, 'rows' => 5]);
?>
</div>
</div>
