Transform an NSAttributedString to plain text

If I understand you correctly you have an NSData, say data, containing an encoded NSAttributedString. To reverse the process:

NSAttributedString *nas = [[NSAttributedString alloc] initWithData:data
                                                           options:nil
                                                documentAttributes:NULL
                                                             error:NULL];

and to get the plain text without attributes you then do:

NSString *str = [nas string];