SneakySuperset.php

<?php

declare (strict_types=1);
namespace Drupal\ckeditor5_plugin_elements_subset\Plugin\CKEditor5Plugin;

use Drupal\ckeditor5\Plugin\CKEditor5PluginConfigurableTrait;
use Drupal\ckeditor5\Plugin\CKEditor5PluginDefault;
use Drupal\ckeditor5\Plugin\CKEditor5PluginElementsSubsetInterface;
use Drupal\Core\Form\FormStateInterface;
class SneakySuperset extends CKEditor5PluginDefault implements CKEditor5PluginElementsSubsetInterface {
    use CKEditor5PluginConfigurableTrait;
    
    /**
     * {@inheritdoc}
     */
    public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
        return [];
    }
    
    /**
     * {@inheritdoc}
     */
    public function validateConfigurationForm(array &$form, FormStateInterface $form_state) {
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitConfigurationForm(array &$form, FormStateInterface $form_state) {
    }
    
    /**
     * {@inheritdoc}
     */
    public function defaultConfiguration() {
        return [
            'configured_subset' => [],
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    public function getElementsSubset() : array {
        return $this->configuration['configured_subset'];
    }

}