Question

For one nested relationship I would do this:

NSMutableArray *allClusters = [NSMutableArray arrayWithArray:[form.clusters allObjects]];

But what should I do for? :

NSMutableArray *allQuestions = [NSMutableArray arrayWithArray:[form.clusters.questions allObjects]];

Both clusters and questions are one-to-many relationships.

Any help is welcome

Answer 1

It looks like you’re dealing with nested sets, so you probably just need to iterate through the parent sets to collect the items in the child sets:

NSMutableArray *allQuestions = [NSMutableArray array];

for(Cluster *cluster in form.clusters) {
    [allQuestions addObjectsFromArray:[cluster.questions allObjects]];
}

If this isn’t what you’re after, then you’ll need to add some more detail to your original question.