/**
  * Customise the edit form so that It uses the VersionedDataObjectDetailsForm as well as make
  * sure that the reading stage is 'Stage'.
  * @param null $id
  * @param null $fields
  * @return mixed
  */
 public function getEditForm($id = null, $fields = null)
 {
     VersionedReadingMode::setStageReadingMode();
     $list = $this->getList();
     $exportButton = new GridFieldExportButton('buttons-before-left');
     $exportButton->setExportColumns($this->getExportFields());
     $listField = GridField::create($this->sanitiseClassName($this->modelClass), false, $list, $fieldConfig = GridFieldConfig_RecordEditor::create($this->stat('page_length'))->addComponent($exportButton)->removeComponentsByType('GridFieldFilterHeader')->removeComponentsByType('GridFieldDeleteAction')->addComponents(new GridFieldPrintButton('buttons-before-left'))->removeComponentsByType('GridFieldDetailForm')->addComponent(new VersionedDataObjectDetailsForm()));
     // Validation
     if (singleton($this->modelClass)->hasMethod('getCMSValidator')) {
         $detailValidator = singleton($this->modelClass)->getCMSValidator();
         $listField->getConfig()->getComponentByType('GridFieldDetailForm')->setValidator($detailValidator);
     }
     $form = CMSForm::create($this, 'EditForm', new FieldList($listField), new FieldList())->setHTMLID('Form_EditForm');
     $form->setResponseNegotiator($this->getResponseNegotiator());
     $form->addExtraClass('cms-edit-form cms-panel-padded center');
     $form->setTemplate($this->getTemplatesWithSuffix('_EditForm'));
     $editFormAction = Controller::join_links($this->Link($this->sanitiseClassName($this->modelClass)), 'EditForm');
     $form->setFormAction($editFormAction);
     $form->setAttribute('data-pjax-fragment', 'CurrentForm');
     $this->extend('updateEditForm', $form);
     VersionedReadingMode::restoreOriginalReadingMode();
     return $form;
 }
 /**
  * @param $data
  * @param $form
  * @return HTMLText|ViewableData_Customised
  */
 public function rollback($data, $form)
 {
     VersionedReadingMode::setStageReadingMode();
     if (!$this->record->canEdit()) {
         return Controller::curr()->httpError(403);
     }
     $this->record->publish('Live', 'Stage');
     $this->record = DataList::create($this->record->class)->byID($this->record->ID);
     VersionedReadingMode::restoreOriginalReadingMode();
     $message = _t('CMSMain.ROLLEDBACKPUBv2', "Rolled back to published version.");
     $form->sessionMessage($message, 'good');
     return $this->edit(Controller::curr()->getRequest());
 }