CODEWITHSUNDEEP
iosobjective-cios8.1
KP_G
KP_G

Reputation: 470

Navigation Stack Management in IOS

While we push pages on the nav stack, I was wondering If I could restrict the maximum number of pages to 10 or so to r. For Example,

If the limit is 4 : A -> B -> C -> D now D is on top and A is the root. When I try to push E, it should remove B from the stack. Since I need rootVC to remain in place. result should be : A -> C -> D -> E.

Also, I know how to remove and add View controllers to the stack, my problem is how to keep track of the navStack while the app is running.

Upvotes: 1

Views: 491

Answers (2)

atulkhatri
atulkhatri

Reputation: 11343

Try this code: 

- (void)limitNavigationStack{
    NSMutableArray* controllers= [self.navCtrl.viewControllers mutableCopy];
    if(controllers.count> MAX_CONTROLLERS){
        [controllers removeObjectAtIndex:1]; // Remove first object after root
        [self.navCtrl setViewControllers:controllers];
    }
}

You can put this code in your appDelegate and call it from viewDidLoad of your viewController.

To make it more generic as you have pointed out, you can inherit from a base view controller and call this method from its viewDidLoad

Upvotes: 1

Gandalf
Gandalf

Reputation: 2417

UINavigationController has a property named viewControllers. Now just before you are going to push a new view controller you can always check how many objects are present in self.navigationController.viewControllers.
If it exceeds your limit then you can go for the navigation stack management manually. 

if(self.navigationController.viewControllers.count > limitCount) {
   // Do the stack management manually for nav controller.
}

Upvotes: 0

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