NodeTypeDeleteConfirm.php

<?php

namespace Drupal\node\Form;

use Drupal\Core\Entity\EntityDeleteForm;
use Drupal\Core\Form\FormStateInterface;

/**
 * Provides a form for content type deletion.
 *
 * @internal
 */
class NodeTypeDeleteConfirm extends EntityDeleteForm {
    
    /**
     * {@inheritdoc}
     */
    public function buildForm(array $form, FormStateInterface $form_state) {
        $num_nodes = $this->entityTypeManager
            ->getStorage('node')
            ->getQuery()
            ->condition('type', $this->entity
            ->id())
            ->count()
            ->execute();
        if ($num_nodes) {
            $caption = '<p>' . $this->formatPlural($num_nodes, '%type is used by 1 piece of content on your site. You can not remove this content type until you have removed all of the %type content.', '%type is used by @count pieces of content on your site. You may not remove %type until you have removed all of the %type content.', [
                '%type' => $this->entity
                    ->label(),
            ]) . '</p>';
            $form['#title'] = $this->getQuestion();
            $form['description'] = [
                '#markup' => $caption,
            ];
            return $form;
        }
        return parent::buildForm($form, $form_state);
    }

}