saving iPhone program state with a deep UINavigationController

Question

Can someone a good way to save the program state (UINavigationController stack, etc) of an iPhone application.

My application obtains a bunch of information from the network and I want to return the person back to the last screen they were on, even if it was 3 or 4 screens deep.

I assume that I will need to reload the data from the network along the way as I recreate the UINavigation controllers. I don't necessarily have a problem with this.

I'm thinking about maybe having my UINavigationController objects implement some type of protocol which allow me to save/set their state? I'm looking to hear from others who may have needed to implement a similar scenario and how they accomplished it.

My application has a UITabbarController at the root and UINavigationController items for each tab bar item.

thanks!

Answer 1

Hi, I did this in one of my apps and from what I can see its quite a manuagel process

For each of your TargetViewControllers you will have to push them onto the view controller, set animated to NO so it looks like it is restoring state.

[[self navigationController] pushViewController:targetViewController animated:NO];

Maybe someone else can point you to a framework that allows you to persist these view controllers.

Answer 2

Here is what I ended up doing as a solution.

I created an protocol which contains a method to "obtain state" and then to "init with state from dictionary method".

So, when the application closes, I loop through all my controllers and ask them for state. And then when application starts back up, I do init with state, passing in the dictionary I serialized. It works well!