src/Forms/HistoryViewerField.php
public function getPreviewEnabled()
    {
        $record = $this->getSourceRecord();
        $previewEnabled = $record && $record instanceof CMSPreviewable;

        $this->extend('updatePreviewEnabled', $previewEnabled, $record);

        return $previewEnabled;
    }
public function getPreviewEnabled()
    {
        $record = $this->getSourceRecord();
        $previewEnabled = $record && $record instanceof CMSPreviewable;

        $this->extend('updatePreviewEnabled', $previewEnabled, $record);

        return $previewEnabled;
    }
public function getPreviewEnabled ( ) { $ record = $ this -> getSourceRecord ( ) ; $ previewEnabled = $ record && $ record instanceof CMSPreviewable ; $ this -> extend ( 'updatePreviewEnabled' , $ previewEnabled , $ record ) ; return $ previewEnabled ; }
Get whether the record is previewable

@return boolean
Get whether the record is previewable