Updating DetailViewController from RootController

I'm trying to create an iPad application with a similar user interface to Apple's Mail application, i.e:

• RootView controller (table view) on the left hand side of the split view for navigation with a multiple view hierarchy. When a table cell is selected a new table view is pushed on the left hand side
• The new view on the left side can update the detail view.

I can accomplish both tasks, but not together. I mean I can make a multi-level table view in the RootController.

Or I can make a single-level table view in the RootController which can update the detailViewController.

Can anyone tell me how to make a multi-level table in the RootController which can update a detailViewController?

There is more source code at the link but below is the method in which I presume I have to declare a new detailViewController (which has to 开发者_如何学编程be put in the UISplitViewController):

- (void)tableView:(UITableView *)TableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {

NSDictionary *dictionary = [self.tableDataSource objectAtIndex:indexPath.row];

//Get the children of the present item.
NSArray *Children = [dictionary objectForKey:@"Children"];

//
if([Children count] == 0) {
    /*
    Create and configure a new detail view controller appropriate for the selection.
    */
    NSUInteger row = indexPath.row;
    UIViewController <SubstitutableDetailViewController> *detailViewController = nil;

    if (row == 0) {
        FirstDetailViewController *newDetailViewController = [[FirstDetailViewController alloc]initWithNibName:@"FirstDetailView" bundle:nil];
        detailViewController = newDetailViewController;
    }

    if (row == 1) {
        SecondDetailViewController *newDetailViewController = [[SecondDetailViewController alloc]initWithNibName:@"SecondDetailView" bundle:nil];
        detailViewController = newDetailViewController;
    }

    // Update the split view controller's view controllers array.
    NSArray *viewControllers = [[NSArray alloc] initWithObjects:self.navigationController, detailViewController, nil];
    splitViewController.viewControllers = viewControllers//nothing happens.....
    [viewControllers release];// 
}

else {

    //Prepare to tableview.
    RootViewController *rvController = [[RootViewController alloc]initWithNibName:@"RootViewController" bundle:[NSBundle mainBundle]];

    //Increment the Current View
    rvController.current_level += 1;

    //Set the title;
    rvController.current_title = [dictionary objectForKey:@"Title"];

    //Push the new table view on the stack
    [self.navigationController pushViewController:rvController animated:YES];

    rvController.tableDataSource = Children;
    [rvController.tableView reloadData]; //without this instrucion,items won't be loaded inside the second level of the table 

    [rvController release];
    }
}

Sorry, but I cannot post my source code as it contains sensitive information. When I have more time available I will create a separate project and upload the code somewhere.

Here are extracts of how I have done it so far (I welcome any feedback).

The RootViewController - Note I have 4 sections in my root table.

#pragma mark -
#pragma mark Table view delegate

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    [tableView deselectRowAtIndexPath:indexPath animated:YES];

    // Detail view logic
    NSUInteger section = indexPath.section;
    UIViewController <SubstitutableDetailViewController> *detailViewController = nil;

    if (section == 2) {
        ProductSearchDetailView *viewController = [[ProductSearchDetailView alloc] initWithNibName:@"ProductSearchDetailView" bundle:nil];
        detailViewController = viewController;
        //[viewController release];
    }
    else {
        DetailViewController *defaultDetailViewController = [[DetailViewController alloc] initWithNibName:@"DetailView" bundle:nil];
        detailViewController = defaultDetailViewController;
        //[defaultDetailViewController release];
    }

    // Navigation logic 
    switch (section) {
        case 0: 
        {
            break;
        }
        case 1:
        {
            break;
        }
        case 2:
        {
            // new Navigation view
            ProductSearchViewController *viewController = [[ProductSearchViewController alloc] initWithNibName:@"ProductSearchViewController" bundle:nil];
            viewController.navigationItem.backBarButtonItem.title = @"Back";
            [self.navigationController pushViewController:viewController animated:YES];
            [viewController release];

            break;  
        }
        case 3:
        {
            StoreLocatorNavController *viewController = [[StoreLocatorNavController alloc] initWithNibName:@"StoreLocatorNavController" bundle:nil];
            viewController.navigationItem.backBarButtonItem.title = @"Back";
            [self.navigationController pushViewController:viewController animated:YES];
            [viewController release];
            break;
        }   
    }

    // Update the split view controller's view controllers array.
    NSArray *viewControllers = [[NSArray alloc] initWithObjects:self.navigationController, detailViewController, nil];
    splitViewController.viewControllers = viewControllers;
    [viewControllers release];

    // Dismiss the popover if it's present.
    if (popoverController != nil) {
        [popoverController dismissPopoverAnimated:YES];
    }

    // Configure the new view controller's popover button (after the view has been displayed and its toolbar/navigation bar has been created).
    if (rootPopoverButtonItem != nil) {
        [detailViewController showRootPopoverButtonItem:self.rootPopoverButtonItem];
    }

    [detailViewController release];

}

NSNotificationCenter part

Add this to ProductSearchViewController:

#pragma mark -
#pragma mark Table view delegate

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

    NSDictionary *itemAtIndex = (NSDictionary *)[self.productResults objectAtIndex:indexPath.row];

    [[NSNotificationCenter defaultCenter] postNotificationName:@"updateProduct" object:itemAtIndex];
}

And finally, add this to ProductSearchDetailViewController:

- (void)viewDidLoad {
    [super viewDidLoad];

    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(updateTheProductDetails:) name:@"updateProduct" object:nil];

}

- (void)updateTheProductDetails:(NSNotification *)notification {
NSDictionary *productDictionary = [NSDictionary dictionaryWithDictionary:[notification object]];

    // product name
    _productName.text = [productDictionary objectForKey:@"ProductDescription"];
}

Hope it helps!