Question

I’m currently relying on the fact that UIApplication is a singleton and I access the models as delegate’s properties, but that seems a long chain to me.

Controller->UIApplication->delegate->Model (->particular property to be set)

Answer 1

Generally speaking, the best way for a view controller to communicate with its model class is to initialize the view controller with the model class. For instance:

- (id)initWithModel:(MYModel *)aModel {
    self = [super initWithNibName:@"ModelViewController" bundle:nil];
    if (self != nil) {
        self.model = aModel;
    }
    return self;
}

There are other approaches for special cases, but this is the best default approach.