Instantiate a new instance of UIViewController within itself

Question

I have an instance of UIViewController displaying a list of items. When the user selects an item I need to create a new instance of UIViewController (populated by a different list of items) and show it. At the moment I'm calling the constructor from within the didSelectRowAtIndexPath method

    RootViewController *rootViewController = [[RootViewController alloc]initWithStyle:UITableViewStylePlain];
UIViewController *targetViewController = rootViewController;
[[self navigationController] pushViewController:targetViewController animated:NO];

But instead of creating a new object it reuses the current one: the new view contains items from the new list as well as from the previous list. So how do I create a new instance of RootViewController from within itself?

Answer 1

You are creating and presenting a new view controller, your problem is elsewhere.

Where are you keeping the data for the table?

Your code does make a new instance, but it's very telling that after creation you are not telling the new view controller what to display - this means that you are getting the data from some more global source, which you must have merely appended the new data onto.

Answer 2

Really vaguely:

1) Import your 2nd level header file into this implementation file. Back in the 2nd level have getters/setters. In your 1st level add another method, -(BOOL)set2ndLevelDataBasedOnXMLSource:(id)source in this method set the appropriate instance variables and do computations to set the data.

2) Your code in didSelectRow should look like:

    if(!rootViewController) {
RootView *rootViewController = [[RootView alloc] initWithstyel...]; }

BOOL result = [self set2ndLevelDataBasedOnXMLSource:_Source_];

if(result) {
[[self navigationController] pushViewController:targetViewController animated:NO]; }

Then you could refactor it:

if([self set2ndLevelDataBasedOnXMLSource:_Source_])  {
[[self navigationController] pushViewController:targetViewController animated:NO]; }

3) in -(BOOL)set2ndLevelDataBasedOnXMLSource:(id)source {

I have:

NSUInteger result;
if(source == true) {

2ndLevelController.section1data = [source (parse for)...];

2ndLevelController.section2data = [source (parse for ...)];

...

result = 1; }
else { result = 0; }

return result;

4) in my 2nd Level, under viewWillDisappear I set all those instance variables to nil (they're mutable arrays)

That's how I did it.