silverstripe / silverstripe-asset-admin

        $fileIds = $vars['ids'];

        $files = $this->getList()->filter("ID", $fileIds)->toArray();

        if (!count($files)) {

            return (new SS_HTTPResponse(json_encode(['status' => 'error']), 404))

                ->addHeader('Content-Type', 'application/json');

        }

        if (!min(array_map(function (File $file) {

            return $file->canDelete();

        $fileClass = File::get_class_for_file_extension(File::get_file_extension($tmpFile['name']));

        $file = Injector::inst()->create($fileClass);

        $uploadResult = $upload->loadIntoFile($tmpFile, $file, $parentRecord ? $parentRecord->getFilename() : '/');

        if(!$uploadResult) {

            $result = ['error' => 'unknown'];

            return (new SS_HTTPResponse(json_encode($result), 400))

                ->addHeader('Content-Type', 'application/json');

        }

        $file->ParentID = $parentRecord->ID;

        $file->write();

        $id = (int) $data['ID'];

        $record = $this->getList()->filter('ID', $id)->first();

        if (!$record) {

            return (new SS_HTTPResponse(json_encode(['status' => 'error']), 404))

                ->addHeader('Content-Type', 'application/json');

        }

        if (!$record->canEdit()) {

            return (new SS_HTTPResponse(json_encode(['status' => 'error']), 401))

                ->addHeader('Content-Type', 'application/json');

        }

        if (!$record->canEdit()) {

            return (new SS_HTTPResponse(json_encode(['status' => 'error']), 401))

                ->addHeader('Content-Type', 'application/json');

        }

        $form->saveInto($record);

        $record->write();