Can't use NSTextField delegate in NSDocument

Question

I have a document-based project with a view-based tableView bound to a coreData Entity. Now I'd like to use the delegate controlTextDidChange: with a static text inside a tableViewColumn.

What I'v done is adding NSTextFieldDelegate to my xxxxDocument.h (my File's owner):

@interface BLDocument : NSPersistentDocument <NSTableViewDelegate,NSTextFieldDelegate>

and implementing in xxxxDocument.m -controlTextDidChange to log something:

-(void)controlTextDidChange:(NSNotification *)obj{
NSLog(@"edited");
}

then in the .xib I connected the StaticText delegate to the file's owner, but nothing works still.

What's wrong with my code?