Child UITableViewController can't receive notification from Parent UITableViewController?

Question

As the question states, I am sending a notification to a child TVC and that child TVC is unable to receive the notification and excute the selector handleNotification: (NSNotification *) paramNotif. I.e. I do not get the NSLog output from that selector.

My code is below and is very self explanatory.

I should add that my parent TVC is also receiving a notification from a modal scene and removing itself from the center in dealloc, however it should still work because its the parent?

Parent UITableViewController

In viewDidAppear

 [self postNotificationToD5TVC];

In postNotificationToD5TVC

NSString *stringWithBOOL = [NSString stringWithFormat:@"%i",[self.workoutRoutine boolValue]];

NSString *kNotifName2 = @"workout";

NSNotification *notification = [NSNotification notificationWithName:kNotifName2 object:self userInfo:@{@"kworkout": stringWithBOOL}];

[[NSNotificationCenter defaultCenter] postNotification:notification];

This works fine as I have NSLogged the method and the value of stringWithBool before Segue

Child UITableViewController

I have a variable BOOL workout

In viewDidLoad

 [self setUpSliders:[self isRoutine]];

In - (BOOL) isRoutine

NSString *kNotifName2 = @"workout";

NSNotificationCenter *center = [NSNotificationCenter defaultCenter];

[center addObserver:self
           selector:@selector(handleNotification:)
               name:kNotifName2
             object:nil;

BOOL isCorrectWorkout = workout;

return isCorrectWorkout;

In handleNotification:(NSNotification *) paramNotif

NSString *workoutString = paramNotif.userInfo[@"kworkout"];
NSInteger workoutInt = [workoutString integerValue];
workout = workoutInt;

NSLog(@"Received notification in D5TVC and value of bool is %i",workout);

Why did you try to use notification for parent - child view controllers ? Whats your purpose? — Vaisakh, Feb 18 '14 at 05:18
@Vaisakh if changes have been made from another view controller to the parent. But this code should still work? do you know why it isnt? — Cescy, Feb 18 '14 at 11:59
i know i can just pass down information, but i want to use notifications — Cescy, Feb 18 '14 at 11:59

score 0 · Answer 1 · answered Feb 18 '14 at 23:06

Problem is I have not invoked the child TVC. So when the notification is being sent from the parent to the child, the child is not listening to the notification. So when the child TVC loads it cannot "go back" and listen to the previous notificiations.

Child UITableViewController can't receive notification from Parent UITableViewController?

1 Answers1