/**
  * when load each widget in sidebars
  * @wp_hook action wp_register_sidebar_widget
  * @param $widget Widget instance
  */
 public function _wp_register_sidebar_widget($widget)
 {
     //_print($widget);
     $wd = isset($widget['callback'][0]) ? $widget['callback'][0] : null;
     //setup features for certain widgets
     if ($wd instanceof WP_Widget && is_active_widget(false, false, $wd->id_base) && class_exists('APF_WidgetFeatures')) {
         APF_WidgetFeatures::setup_features_widgets($wd);
     }
 }
 /**
  * @param $slug
  * @param $tab
  * @param $setting
  */
 public static function init($slug, $tab, $setting)
 {
     $tab['slug'] = $slug;
     self::$setting = $setting;
     self::$setting_tab = $tab;
     add_action('load_' . $setting::HW_SETTINGS_PAGE . '_' . $setting::valid_tab_slug($slug), __CLASS__ . '::replyToAddFormElements');
 }