class UnpublishByKeywordComment

class UnpublishByKeywordComment extends ConfigurableActionBase implements ContainerFactoryPluginInterface {
    
    /**
     * The comment entity builder handler.
     *
     * @var \Drupal\Core\Entity\EntityViewBuilderInterface
     */
    protected $viewBuilder;
    
    /**
     * The renderer.
     *
     * @var \Drupal\Core\Render\RendererInterface
     */
    protected $renderer;
    
    /**
     * Constructs a UnpublishByKeywordComment object.
     *
     * @param array $configuration
     *   A configuration array containing information about the plugin instance.
     * @param string $plugin_id
     *   The plugin ID for the plugin instance.
     * @param mixed $plugin_definition
     *   The plugin implementation definition.
     * @param \Drupal\Core\Entity\EntityViewBuilderInterface $comment_view_builder
     *   The comment entity builder handler.
     * @param \Drupal\Core\Render\RendererInterface $renderer
     *   The renderer.
     */
    public function __construct(array $configuration, $plugin_id, $plugin_definition, EntityViewBuilderInterface $comment_view_builder, RendererInterface $renderer) {
        parent::__construct($configuration, $plugin_id, $plugin_definition);
        $this->viewBuilder = $comment_view_builder;
        $this->renderer = $renderer;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
        return new static($configuration, $plugin_id, $plugin_definition, $container->get('entity_type.manager')
            ->getViewBuilder('comment'), $container->get('renderer'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function execute($comment = NULL) {
        $build = $this->viewBuilder
            ->view($comment);
        $text = $this->renderer
            ->renderPlain($build);
        foreach ($this->configuration['keywords'] as $keyword) {
            if (strpos($text, $keyword) !== FALSE) {
                $comment->setUnpublished();
                $comment->save();
                break;
            }
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function defaultConfiguration() {
        return [
            'keywords' => [],
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
        $form['keywords'] = [
            '#title' => $this->t('Keywords'),
            '#type' => 'textarea',
            '#description' => $this->t('The comment will be unpublished if it contains any of the phrases above. Use a case-sensitive, comma-separated list of phrases. Example: funny, bungee jumping, "Company, Inc."'),
            '#default_value' => Tags::implode($this->configuration['keywords']),
        ];
        return $form;
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitConfigurationForm(array &$form, FormStateInterface $form_state) {
        $this->configuration['keywords'] = Tags::explode($form_state->getValue('keywords'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function access($object, AccountInterface $account = NULL, $return_as_object = FALSE) {
        
        /** @var \Drupal\comment\CommentInterface $object */
        $result = $object->access('update', $account, TRUE)
            ->andIf($object->status
            ->access('edit', $account, TRUE));
        return $return_as_object ? $result : $result->isAllowed();
    }

}