hasExtension(Versioned::class)) { $actions->push(new FormAction('publish', 'Publish')); } } /** * Adds extra fields to this form * * @param FieldList $fields * @param Controller $controller * @param string $name * @param array $context */ public function updateFormFields(FieldList &$fields, Controller $controller, $name, $context = []) { // Add preview link if (empty($context['Record'])) { return; } $record = $context['Record']; if ($record->hasExtension(Versioned::class)) { $link = $controller->Link('preview'); $fields->unshift( new LiteralField( "PreviewLink", sprintf('Preview', Convert::raw2att($link)) ) ); } } public function publish($data, $form) { // noop } public function preview() { // noop } }