newsupernova/app/code/Magefan/Blog/Block/Adminhtml/Edit/DeleteButton.php

<?php
/**
 * Copyright © 2016 Ihor Vansach (ihor@magefan.com). All rights reserved.
 * See LICENSE.txt for license details (http://opensource.org/licenses/osl-3.0.php).
 *
 * Glory to Ukraine! Glory to the heroes!
 */
namespace Magefan\Blog\Block\Adminhtml\Edit;

use Magento\Framework\View\Element\UiComponent\Control\ButtonProviderInterface;

/**
 * Class DeleteButton
 */
class DeleteButton extends GenericButton implements ButtonProviderInterface
{

    /**
     * @return array
     */
    public function getButtonData()
    {
        $data = [];
        if ($this->getPostId()) {
            $data = [
                'label' => __('Delete'),
                'class' => 'delete',
                'on_click' => 'deleteConfirm(\'' . __(
                    'Are you sure you want to do this?'
                ) . '\', \'' . $this->getDeleteUrl() . '\')',
                'sort_order' => 20,
            ];
        }
        return $data;
    }

    /**
     * @return string
     */
    public function getDeleteUrl()
    {
        return $this->getUrl('*/*/delete', ['id' => $this->getPostId()]);
    }
}