CODEWITHSUNDEEP
iosobjective-cstoryboardinstantiationviewdidload
Thomas Besnehard
Thomas Besnehard

Reputation: 2095

instantiateViewControllerWithIdentifier seems to call viewdidload

I am trying to push a ViewController programmatically into a navigation controller, And I'm using my storyboard to create it.

here is my code :

+ (void) pushViewController:(NSString *) identifier ForItems:(NSMutableArray *) items sender:(UIViewController *) sender {
    GenericViewController *viewController = (GenericViewController *)[sender.storyboard instantiateViewControllerWithIdentifier:identifier];

    viewController.items = [[NSMutableArray alloc] init];
    [viewController.items removeAllObjects];
    [viewController.items addObject:[[NSMutableArray alloc] init]];
    [viewController.items[0] addObjectsFromArray:items];

    [sender.navigationController pushViewController:viewController animated:YES];
}

In GenericViewController viewDidLoad I'm using my items. Thanks to some break points I've seen that GenericViewController viewDidLoad juste after the instantiateViewControllerWithIdentifier with an items equal to nil.

I thought that MyViewController viewDidLoad is called during the pushViewController method.

Any idea why viewDidLoad is called during instantiateViewControllerWithIdentifier ?

---Update :---

Here my viewDidLoad

- (void)viewDidLoad
{
    for (MyItem *currentItem in self.items[0]) {
        [Do Something]
    }

    [super viewDidLoad];


    [...]
}

self.items is nil. so nothing is done.

Upvotes: 9

Views: 8999

Answers (4)

nik
nik

Reputation: 31

You can use [vc loadViewIfNeeded] in Objective-C or vc.loadViewIfNeeded() in Swift.

apple: loadViewIfNeeded

Upvotes: 3

Deivi
Deivi

Reputation: 225

To anyone that might still have the same problem.

I had a similar situation and solved it by just calling loadViewIfNeeded().

let sb: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let controller = sb.instantiateViewControllerWithIdentifier("LoadingView") as! LoadingViewController
controller.loadViewIfNeeded()

I could then access everything inside the view.

Upvotes: 8

Mark Semsel
Mark Semsel

Reputation: 7155

As voyage11 mentioned, viewDidLoad is called when the controller's view is loaded into memory, although someone has pointed out that this does not necessarily occur during the instantiateViewControllerWithIdentifier method.

Following your example code, I'd put the loop in the viewWillAppear method:

- (void) viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];  // good practice to call the super
    for (MyItem *currentItem in self.items[0]) {
        [Do Something]
    }
}

Upvotes: 0

Ricky
Ricky

Reputation: 10505

See: https://developer.apple.com/library/ios/documentation/uikit/reference/UIViewController_Class/Reference/Reference.html#//apple_ref/occ/instm/UIViewController/viewDidLoad

viewDidLoad is called when the controller's view is loaded into memory.

viewWillAppear Notifies the view controller that its view is about to be added to a view hierarchy. I think this is when [self.navigationController pushViewController:viewController animated:YES]; is called.

viewDidAppear Notifies the view controller that its view was added to a view hierarchy. This is when MyViewController is added into navigationController.

Upvotes: 1

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