UINavigationController State Restoration (without Storyboards)

Question

I\'ve been toying around with state restoration. In the code below, the scroll position of the UITableViewController gets restored, however, if I were to tap through into the de

Answer 1

Since you are doing this in code and not via Storyboard, you will need to provide not only a restorationIdentifier but also a restorationClass to you detail view controller.

You could leave it unassigned in which case -(UIViewController *)application:(UIApplication *)application viewControllerWithRestorationIdentifierPath:(NSArray *)identifierComponents coder:(NSCoder *)coder gets called on the application delegate to make the object (view controller with a restorationIdentifier but no restorationClass).

Try the following (please note the UIViewControllerRestoration protocol):

@interface MyViewController ()
@end

@implementation

- (id)init
{
    self = [super init];
    if (self) {
        // Custom initialization
    }

    if( [self respondsToSelector:@selector(restorationIdentifier)] ){
        self.restorationIdentifier = @"DetailViewController";
        self.restorationClass = [self class];
    }
    return self;
}

#pragma mark - State restoration

+ (UIViewController *)viewControllerWithRestorationIdentifierPath:(NSArray *)identifierComponents coder:(NSCoder *)coder
{
    UIViewController *viewController = [[self alloc] init];

    return viewController;
}

@end

Also note that this is a very simple example, usually you might have a lot more interesting things going on in -viewControllerWithRestorationIdentifierPath:coder: