How to use the “ALL” aggregate operation in a NSPredicate to filter a CoreData-based collection

Question

Based on the data model below

And based on user input I create a NSSet of managedObjects

Answer 1

How about using a compound predicate? As I understand you want to return all Entries that match a list of tags not just any of them. One approach would be to create a predicate for each tag, then AND them together using a compound predicate.

NSMutableArray *predicates = [[NSMutableArray alloc] init];
for (Tag *tag in selectedTags) {
    [predicates addObject:[NSPredicate predicateWithFormat:@"ANY entryTags.tagName MATCHES %@", tag.tagName]];
}
NSPredicate *compoundPredicate = [NSCompoundPredicate andPredicateWithSubpredicates:predicates];

This should achieve want you want. Then just set this predicate on your request.