getUploadDescription method
Asks the server to reserve a key and sign a one-shot upload for it.
The caller does not name the key: folder says where in the bucket the
object belongs, fileName suggests its readable part, and
fileExtension describes the bytes actually being sent — which is not
always the extension of the file that was picked. The ticket carries the
signed description and the id of the reservation to confirm with.
Implementation
@override
Future<DwUploadTicket?> getUploadDescription({
String? folder,
required String fileExtension,
String? fileName,
}) {
final answer = answerUploadDescription;
if (answer == null) {
throw DwUnpreparedServerCall(
'getUploadDescription',
'answerUploadDescription',
'folder: $folder, fileExtension: $fileExtension, fileName: $fileName',
);
}
return answer(folder, fileExtension, fileName);
}