MailCore2, fetch only UNREAD messages, or know which ones are UNREAD

Question

I am able to fetch all messages using fetchMessagesByUIDOperationWithFolder:, however, message.flags all return 0 when some messages are unread, most are read and some are starred.

MCOIMAPMessagesRequestKind requestKind = MCOIMAPMessagesRequestKindHeaders;
NSString *folder = @"INBOX";
MCOIndexSet *uids = [MCOIndexSet indexSetWithRange:MCORangeMake(1, UINT64_MAX)];

MCOIMAPFetchMessagesOperation *fetchOperation = [session fetchMessagesByUIDOperationWithFolder:folder requestKind:requestKind uids:uids];
[fetchOperation start:^(NSError * error, NSArray * fetchedMessages, MCOIndexSet * vanishedMessages)
{
    if ( ! error )  {
        for ( MCOIMAPMessage * message_ in fetchedMessages )  {
           // I only want UNREAD messages.
        }
    }
}

I have tried using if ( message_.flags & MCOMessageFlagSeen ) but still, all flags return as 0.

What is the proper way to see if the message is UNREAD?

Answer 1

For anyone having the same issue, you need to also include the kind request for flags: MCOIMAPMessagesRequestKindFlags.

MCOIMAPMessagesRequestKind requestKind = MCOIMAPMessagesRequestKindHeaders|MCOIMAPMessagesRequestKindFlags;

Then, look for the unread flag:

for ( MCOIMAPMessage * message_ in fetchedMessages )  {
    if ( message_.flags == 0 ) {
        // I have a suspicion that this is not the correct
        // way to do this, but it seems to work the way I need.
    }
}

Answer 2

You can use 0 or better as below, which is 0 too, but who knows if they decide to change it to something else later:

if(message_.flags == MCOMessageFlagNone)