public function getEditForm($id = null, $fields = null)
 {
     $record = GlobalContent::inst();
     $fields = $record->getCMSFields();
     $actions = $this->getCMSActions($record);
     if ($record && !$record->canView()) {
         return Security::permissionFailure($this);
     }
     // Tab nav in CMS is rendered through separate template
     /** @var TabSet $root */
     $root = $fields->fieldByName('Root');
     $root->setTemplate('CMSTabSet');
     $form = $this->buildForm($fields, $actions);
     $this->extend('updateEditForm', $form);
     $form->loadDataFrom($record);
     $this->extend('updateEditFormWithData', $form);
     return $form;
 }
 public static function GlobalContent($key = null)
 {
     $inst = GlobalContent::inst();
     return is_null($key) ? $inst : $inst->{$key};
 }