UINavigationControllers: How to pass value to higher (parent?) controller in stack?

Question

I have SendingController which push to nav stack SendingDeatilsController (which one has a TableView). User should should pick in TableView one row (it checked by Checkmark) and I would like to pass the value of this row (let it will NSString object) to the SendingController.

How can I realize this behaviour in my application? And is SendingController parent for SendingDetailController (attribute parentController of SDC refers to SC) ??

Answer 1

If you want to implement this behaviour, pass the SendingDetailController a reference to the previous view controller. This way the detail view controller can send a message to the previous one on the stack.

In your SendingDetailController define a weak reference :

// in .h
SendingController *sendingController;
@property(assign) SendingController *sendingController;

// in .m
@synthesize sendingController;

-(void)tableView:(UITableView *)tableView
 didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    // retrieve the string and send the message
    [sendingController didSelectString:theString];
}

Now before pushing the SendingDetailController on the stack don't forget to set its sendingController property.

// .m
// where you push the vc
if(!sendingDetailController) {
    sendingDetailController = [[SendingDetailController alloc]
                               initWithNibName:@"TheNIBName"
                                        bundle:nil];
    sendingDetailController.sendingController = self;
}
[self.navigationController pushViewController:sendingDetailController
                                     animated:YES];

and write the method that will recieve the string.

-(void)didSelectString:(NSString *)aString {
    // do anything with string
    [self.navigationController popViewControllerAnimated:YES];
}

This should do the job.