common/widgets/BasketModal.php

<?php
namespace common\widgets;
use yii\base\Widget;
class BasketModal extends Widget
{
    public function init(){
        parent::init();
    }
    public function run()
    {
        $sessionData = \Yii::$app->session->get('order');
        $count = count($sessionData);
        if(is_array($sessionData) && !empty($sessionData)){
            return $this->render('busket_modal',[
                'items'=>$sessionData,
                'count' => $count
            ]);
        }
    }
}