iPad UISplitViewController multiple root views

Question

I am developing for iPad and have created a standard UISplitViewController application using the template provided in Xcode - a standard UITableView on the left and a detail view on the right.

I have modified the template so that when a user selects a table cell from the left view it pushes a new table view in it's place (still on the left side). This works without issue, but I would like to be able to update the existing detail view from the new table view - kinda like how Apple's Mail application works.

- I am not trying to create multiple views on the detail view (right hand side) - I've read the documentation and seen the sample code provided by Apple.

I read/followed many tutorials, but can't seem to get this relatively simple view hierarchy to work.

More detail:-

Using detailViewController.detailItem = @"Test"; in the RootView didSelectTableRowAtIndexPath delegate method updates the Detail view label. Using the exact same code in the newly pushed Table View does not update the label - am I missing a reference point or something??

Since posting I've tried to use protocols & delegates to update a label on the detail view. The label updates correctly when changed from the Root View using the new methods, however, when I push a new view onto the root view (left hand side) I can no longer update the label.

Answer 1

At some point after creating the RootViewController (or maybe even in a custom init method) you are setting the delegate for the DetailViewController, its a common mistake that when a new rootViewController is pushed onto the NavController that you forget to set the delgate again.

You probably are creating a new controller in the:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath;

method and recording/incrementing the level of the new controller before you push it onto the navController. After you create this new controller, set the delegate again.

newRootController.myDelegate = self.myDelegate;

Before you do this If you NSLog the delegate just before you use it, you will probably find its nil.