Question

I don’t get how from an array of Strings (parentRootItems), I do get objects with this code:

NSArray *parentRootItems = [pFolder rootItems];
NSLog(@"parentRootItems %@", [parentRootItems description]);

NSString *keyPath = [NSString stringWithFormat:@"@distinctUnionOfObjects.%@", metadata.lookupItemsKeyPath];
NSLog(@"keyPath %@", keyPath);

NSArray *managedItems = [parentRootItems valueForKeyPath:keyPath];
NSLog(@"managedItems %@", [managedItems description]);

Thanks

Output

parentRootItems (Self-Inflicted Wounds / Rebirth)
                (Self-Inflicted Wounds / Rebirth)
                ...


keyPath @distinctUnionOfObjects.Series

 managedItems (
    <CBSeries: 0x1ddf3c0> (entity: Series; id: 0x1ddf260 <x-coredata://2B6F6719-9BCB-4C5C-B027-0DE2C7C1910C/Series/p350> ; data: {
    ClzID = 37268;
    Comics = "<relationship fault: 0x1de3790 'Comics'>";
    Complete = 0;
    DisplayName = Annihilators;
    Frequency = nil;
    ISSN = nil;
    Image = nil;
    Name = nil;
    NumIssues = 0;
    SortName = Annihilators;
    Stories = "<relationship fault: 0x1de39c0 'Stories'>";
    The = nil;
    URL = nil;
    UniqueID = 1;
}),
    <CBSeries: 0x1dd2940> (entity: Series; id: 0x1db4b60 <x-coredata://2B6F6719-9BCB-4C5C-B027-0DE2C7C1910C/Series/p354> ; data: {
    ClzID = 3856;
    Comics = "<relationship fault: 0x1de4230 'Comics'>";
    Complete = 0;
    DisplayName = Futurama;
    Frequency = nil;
    ISSN = nil;
    Image = nil;
    Name = nil;
    NumIssues = 0;
    SortName = Futurama;
    Stories = "<relationship fault: 0x1de4510 'Stories'>";
    The = nil;
    URL = nil;
    UniqueID = 9;
}),
...

Answer 1

parentRootItems isn’t an array of strings. By the looks of this it is an array of managed objects, which each have a .Series attribute, which points to another managed object, of Series entity.

You are getting back an array containing each Series entity used by the objects in parentRootItems, with any duplicates removed.

To see more clearly what is in parentRootItems, use the following log message instead of the description which is what you are currently doing:

NSLog(@"Parent root items: %@",parentRootItems);