class FilterTestRestrictTagsAndAttributes

class FilterTestRestrictTagsAndAttributes extends FilterBase {
    
    /**
     * {@inheritdoc}
     */
    public function process($text, $langcode) {
        $allowed_tags = array_filter($this->settings['restrictions']['allowed'], function ($value) {
            return is_array($value) || (bool) $value !== FALSE;
        });
        return new FilterProcessResult(Xss::filter($text, array_keys($allowed_tags)));
    }
    
    /**
     * {@inheritdoc}
     */
    public function getHTMLRestrictions() {
        $restrictions = $this->settings['restrictions'];
        // The configuration system stores FALSE as '0' and TRUE as '1'. Fix that.
        if (isset($restrictions['allowed'])) {
            foreach ($restrictions['allowed'] as $tag => $attributes_or_bool) {
                if (!is_array($attributes_or_bool)) {
                    $restrictions['allowed'][$tag] = (bool) $attributes_or_bool;
                }
                else {
                    foreach ($attributes_or_bool as $attr => $attribute_values_or_bool) {
                        if (!is_array($attribute_values_or_bool)) {
                            $restrictions['allowed'][$tag][$attr] = (bool) $attribute_values_or_bool;
                        }
                        else {
                            foreach ($attribute_values_or_bool as $attribute_value => $bool) {
                                $restrictions['allowed'][$tag][$attr][$attribute_value] = (bool) $bool;
                            }
                        }
                    }
                }
            }
        }
        return $restrictions;
    }

}