_filter_html_escape example

class FilterHtmlEscape extends FilterBase {

  /** * {@inheritdoc} */
  public function process($text, $langcode) {
    return new FilterProcessResult(_filter_html_escape($text));
  }

  /** * {@inheritdoc} */
  public function getHTMLRestrictions() {
    // Nothing is allowed.     return ['allowed' => []];
  }

  /** * {@inheritdoc} */