iOS Delegate not called

Question

For a project I need to be able to send a status back from "secondTableViewController" to "firstTableViewController". I followed some tutorials on delegates but I don't seem to get it to work. When I want to call the method in firstTableViewController from the secondTableViewController I do a check to see if "delegate" property is empty, and every time it is..

This is my code:

SecondTableViewController.h

@protocol SendStatusDelegate <NSObject>
@required
-(void)didStatusChanged;

@end // eof delegate protocol

@interface SecondTableViewController : UITableViewController

@property (nonatomic, assign) id<SendStatusDelegate> delegate;

@end

SecondTableViewController.m

// Status is changed on row click
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (self.delegate) { // This is never called because delegate looks to remain empty
        [self.delegate didStatusChanged];
    }
}

FirstTableViewController.h

@interface FirstTableViewController : UITableViewController <SendStatusDelegate>

@end

FirstTableViewController.m

The only thing that goes on here is implementing the -(void)didStatusChanged method.

Answer 1

First You need to set the delegate to self in FirstTableViewController when you init the SecondTableViewController . say on didSelectRowAtIndexPath: you are calling the SecondTableViewController in that case,

FirstTableViewController.m

// Status is changed on row click
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    SecondTableViewController *secondTableVC = [SecondTableViewController alloc] init];
    secondTableVC.delegate = self;

}

Answer 2

In the FirstTableViewController where you create the SecondTableViewController instance you should assign the delegate of the created instance to FirstTableViewController

ie

secondTableViewControllerInstance.delegate = self;

in FirstTableViewController

Answer 3

Your FirstTableViewController Class should conform the SendStatusDelegate Like

@interface FirstTableViewController : UITableViewController <SendStatusDelegate>

And then then assign the delegate of SecondViewController instance by self Like

SecondTableViewControllerInstance.delegate = self;