Properly declare delegation in Objective C (iPhone)
- by Gordon Fontenot
Ok, This has been explained a few times (I got most of the way there using this post on SO), but I am missing something. I am able to compile cleanly, and able to set the delegate as well as call methods from the delegate, but I'm getting a warning on build:
No definition of protocol 'DetailViewControllerDelegate' is found
I have a DetailViewController and a RootViewController only. I am calling a method in RootViewController from DetailViewController. I have the delegate set up as so:
In RootViewController.h:
#import "DetailViewController.h"
@interface RootViewController : UITableViewController <NSFetchedResultsControllerDelegate, DetailViewControllerDelegate> //Error shows up here
{
//Some Stuff Here
}
//Some other stuff here
@end
In RootViewController.m I define the delegate when I create the view using detailViewController.delegate = self
In DetailViewController.h:
@protocol DetailViewControllerDelegate;
#import "RootViewController.h"
@interface DetailViewController : UITableViewController <UITextFieldDelegate>
{
id <DetailViewControllerDelegate> delegate;
}
@property (nonatomic, assign) id <DetailViewControllerDelegate> delegate;
@end
@protocol DetailViewControllerDelegate
//some methods that reside in RootViewController.m
@end
I feel weird about declaring the protocol above the import in DetailViewController.h, but if I don't it doesn't build. Like I said, the methods are called fine, and there are no other errors going on. What am I missing here?
