Question

I have the following code that sorts by ascending.

NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"someproperty.name" ascending:YES];
    NSMutableArray   *sortedReleases = [NSMutableArray arrayWithArray:[unsortedarray sortedArrayUsingDescriptors:[NSArray arrayWithObject:sortDescriptor]]];
    [sortDescriptor release];

What I want to do is do a sort where:

Show the ones where a sortedRelease is being followed by active current user (complex logic that goes in a function??)

This is what I need in my custom function:

for (Release *release in sortedReleases){

if( [[[MainController sharedMainController] activeUser] isFollowingRelease:release] ){

return NSOrderedAscending;
}

}

Sort the rest using acsending (how it is doing it currently)

How would I get about doing that?

I know I asked this question earlier and maybe I asked it the wrong way but that was not what i was looking for. I want to be able to sort based on a result of a function. And then alphabetically.

UPDATED CODE:

 NSArray *sortedReleases = [theReleases sortedArrayUsingComparator:^(id a, id b) {
        Release *left = (Release*)a;
        Release *right = (Release*)b;


        if(( [[[MainController sharedMainController] activeUser] isFollowingRelease:left] )&&([[[MainController sharedMainController] activeUser] isFollowingRelease:right])){

           //sort alphabetically ????
        }
        else if (([[[MainController sharedMainController] activeUser] isFollowingRelease:left])&&(![[[MainController sharedMainController] activeUser] isFollowingRelease:right]))
        {
            return (NSComparisonResult)NSOrderedDescending;
        }
        else if ((![[[MainController sharedMainController] activeUser] isFollowingRelease:left])&&([[[MainController sharedMainController] activeUser] isFollowingRelease:right]))
        {
             return (NSComparisonResult)NSOrderedAscending;
        }

        return [left compare:right]; //getting a warning here about incompatible types
    }];

Answer 1

Here is how you sort arrays using custom logic, with alphabetic sorting for tie-breaking:

NSArray *sortedArray = [unsortedArray sortedArrayUsingComparator:^(id a, id b) {
    Release *left = (Release*)a;
    Release *right = (Release*)b;
    BOOL isFollowingLeft = [[[MainController sharedMainController] activeUser] isFollowingRelease:left];
    BOOL isFollowingRight = [[[MainController sharedMainController] activeUser] isFollowingRelease:right];
    if (isFollowingLeft && !isFollowingRight) {
        return (NSComparisonResult)NSOrderedDescending;
    } else if (!isFollowingLeft && isFollowingRight) {
        return (NSComparisonResult)NSOrderedDescending;
    }
    return [left.name compare:right.name];
}];