Scroll pager scrolling in Yii2

I am using Yii2 with a scroll pager extension: http://kop.github.io/yii2-scroll-pager/

Here's my code:

echo yii\widgets\ListView::widget([
    'dataProvider' => $boards,
    'itemView' => 'boards',
    'layout' => $template,
    'itemOptions' => ['class' => 'item'],
    'pager' => ['class' => \kop\y2sp\ScrollPager::className()]
]);

      

        
        
        
      

    

and I am collecting data. The creator from modal code is shown below.

$dataProvider = new ActiveDataProvider([
        'query' => Boards::find(),
        'pagination' => array('pageSize' => 3),
    ]);

    return $dataProvider;

      

        
        
        
      

    

But I am getting the following exception

PHP Notice - yii \ base \ ErrorException Undefined variable: boards

Can anyone tell me what is wrong?