Thursday, May 2, 2013

iOS Creating Custom Delegates in iOS6 with ARC

So you want two Objects to talk to each other more than a little bit? Here is what to do by example.  Lets say we have our MainViewController and a new SearchViewController that you want a delegate attached to it. This is all you need to do.

In SearchViewController.h
@protocol SearchViewDelegate <NSObject>
@optional
@required
-(void)didAskToSearch:(NSString*)string;
@end

@interface SearchViewController : UIViewController {
}
@property (nonatomic, assign) id <SearchViewDelegate> delegate;
@end

optional has non-required methods and required of course has required methods. 

In SearchViewController.m;
    [_delegate didAskToSearch: [self searchRequestDetails]];

this is put anywhere in the code when you want it to send the information back to the other object. 

In the MainViewController.h;
@interface MainViewController : UIViewController <SearchViewDelegate> {
}

In MainViewController.m;
SearchViewController *searcher = [[SearchViewController alloc]init];
searcher.delegate = self;

#pragma mark - SearchViewControllerDelegates
-(void)didAskToSearch:(NSString*)string{
     //do whatever you want with the string results
}

When creating the object, make sure the tell the delegate you have those methods. Then you just have to create the methods as per it is required. 

Helpful link
http://stackoverflow.com/questions/12020539/how-to-make-custom-delegate-in-ios-app

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