Pass object between WKInterfaceControllers in Page-Based WatchKit App

Question

I've been struggling over the past little while with something that should be dead easy, but I just can't seem to get to work. I'm bolting on a WatchKit interface to an existing iPhone app that I have for sale in the App Store, developed in Objective-C. I simply want to pass an object to the next WKInterfaceController when I swipe to segue to it.

Given WatchKit doesn't have prepareForSegue, and page-based Relationship Segues don't have identifiers (from what I can tell) which would enable me to use contextForSegueWithIdentifier, how should I go about passing an object?

I have tried:

 _names = [[NSArray alloc]initWithObjects:@"RootInterfaceController",@"StatusInterfaceController",nil];
NSString *passedBAL=@"TEST";
    _contextObject=[[NSArray alloc]initWithObjects:passedBAL, nil];
    if (firstLoad) {
        [WKInterfaceController reloadRootControllersWithNames:_names
                                                     contexts:_contextObject];
        firstLoad=NO;

in -(void)willActivate, where I have set a value for the _passedBal property in -(void)awakeWithContext:(id)context, and a BOOL to avoid the infinite recursion this method seems to create (very kludgy fix in my view), yet the value is always nil when I arrive at the next WKInterfaceController. When I set breakpoints and mouse over the variable in the StatusInterfaceController, it seems to set the value, but as the program continues to execute, it nils it out immediately, though not in response to anything I have written in my code.

Any help would be appreciated, as I have been pulling out my hair on this one, and as I said, it should dead simple.

EDIT:

_passedBAL was a simple NSString property, but i've changed it in the above to just a straight-up NSString to put in the array for clarity's sake and added my StatusInterfaceController code. Thanks in advance :)

In my StatusInterfaceController.h , I have the following:

#import <WatchKit/WatchKit.h>
#import <Foundation/Foundation.h>
#import "InterfaceController.h"
@interface StatusInterfaceController : WKInterfaceController
@property (strong, nonatomic) NSString *passedBAL;

@end

While in my StatusInterfaceController.m I have:

#import "StatusInterfaceController.h"

@interface StatusInterfaceController ()
@end

@implementation StatusInterfaceController

- (void)awakeWithContext:context {
    [super awakeWithContext:context];
    _passedBAL=[context objectAtIndex:0];
    NSLog(@"Passed BAL is equal to %@",_passedBAL);
    // Configure interface objects here.
}

Answer 1

You can do this in two ways:

In your storyboard you set an identifier in your segue:

and then you can use contextForSegueWithIdentifier:

- (id)contextForSegueWithIdentifier:(NSString *)segueIdentifier {
     if ([segueIdentifier isEqualToString:@"yourIdentifier"]) {
        return aDictionaryWithYourInformation;
     }
}

Or you can pass information with a context via code, with:

[self pushControllerWithName:@"YourViewController"
                     context:aDictionary];

This context is a dictionary and you have access to this dictionary in the - (void)awakeWithContext:(id)context

EDIT

Now that we can see more code it seems to me that there is some confusion in your reload and awakeWithContext.

In the reload method you pass an array of contexts, that basically is a context for each interface. Then, you receive a single context in your awakeWithContext, that in your case is the string you want. Therefore, your awakeWithContext in your Root Interface Controller should be the context:

- (void)awakeWithContext:context {
    [super awakeWithContext:context];
   NSLog(@"Passed BAL is equal to %@",context);
}

This method will be nil in your StatusInterfaceController since you are not passing any context to it.