How to initiate a view controller from another view controller? - ios

Question

I have a table view controller called StackViewController, this is where I hold a list of todo's that has been created in CreateViewController...
I have an NSString property in StackViewController called currentTarget that represent the first to do in the stack:
import <UIKit/UIKit.h>
#interface StackTableViewController : UITableViewController
#property (nonatomic, strong) NSString *currentTarget;
#end
This property holds the first NSString object in the table view, I get it like this:
#import "StackTableViewController.h"
#import "Target.h"
#import "CoreDataStack.h"
#interface StackTableViewController () <NSFetchedResultsControllerDelegate>
#property (nonatomic, strong) NSFetchedResultsController *fetchedResultController;
#end
#implementation StackTableViewController
- (void)viewDidLoad {
[super viewDidLoad];
[self.fetchedResultController performFetch:nil];
NSIndexPath *indexPath = [NSIndexPath indexPathForItem:0 inSection:0];
Target *target = [self.fetchedResultController objectAtIndexPath:indexPath];
self.currentTarget = target.body;
}
Now, when I log into my home page which called HomeViewController I want to initiate the StackTableViewController and get its currentTatget property value...
I know that there are delegate to help you notify other views when a change has happened, but in my case I want to get this property value before even I have been in this page (StackTableViewController), because the HomeViewController is the first view controller that is loaded (my initial view controller) and I what to access this property when I was just logged in to the app and populate a label with it.
How should I do this?
I thought maybe something like this:
#import "HomeViewController.h"
#import "CreateViewController.h"
#import "StackTableViewController.h"
#interface HomeViewController ()
#property (strong, nonatomic) IBOutlet UILabel *targetLabel;
#end
#implementation HomeViewController
- (void)viewDidLoad {
[super viewDidLoad];
StackTableViewController *vc = [[StackTableViewController alloc] init];
NSString *current = vc.currentTarget;
self.targetLabel.text = current;
}
But i'm missing something here...my label is not populated...
I think there is something with the views lifecycle.
i'm a newbie please help me to figure this out...thanks

Answer 1

Don't do anything to do with graphics in viewDidLoad. The earliest you want to do it is in viewWillAppear (most of the time) and occasionally you will need to do it in viewDidAppear.
Try the same code in viewWillAppear and it should work.
Oh right, since your other viewController is setup in viewDidLoad, you need to call
[stackTableViewController view] on your stackTableViewController after you alloc init it. Seems weird, but this actually works. This is because the StackTableViewController doesn't have its calculation done when you initialize it, it runs through it in it's viewDidLoad delegate.
- (void)viewDidLoad {
[super viewDidLoad];
StackTableViewController *vc = [[StackTableViewController alloc] init];
[vc view];
NSString *current = vc.currentTarget;
self.targetLabel.text = current;
}