class GlobalAttribute

class GlobalAttribute extends CKEditor5PluginDefault {
    
    /**
     * {@inheritdoc}
     */
    public function getDynamicPluginConfig(array $static_plugin_config, EditorInterface $editor) : array {
        // This plugin is only loaded when filter_html is enabled.
        assert($editor->getFilterFormat()
            ->filters()
            ->has('filter_html'));
        $filter_html = $editor->getFilterFormat()
            ->filters('filter_html');
        $restrictions = HTMLRestrictions::fromFilterPluginInstance($filter_html);
        // Determine which tags are allowed by filter_html, excluding the global
        // attribute `*` HTML tag, because that's what we're expanding this to right
        // now.
        $allowed_elements = $restrictions->getAllowedElements();
        unset($allowed_elements['*']);
        $allowed_tags = array_keys($allowed_elements);
        // Update the static plugin configuration: generate a `name` regular
        // expression to match any of the HTML tags supported by filter_html.
        // @see https://ckeditor.com/docs/ckeditor5/latest/features/general-html-support.html#configuration
        $dynamic_plugin_config = $static_plugin_config;
        $dynamic_plugin_config['htmlSupport']['allow'][0]['name']['regexp']['pattern'] = '/^(' . implode('|', $allowed_tags) . ')$/';
        return $dynamic_plugin_config;
    }

}