UINavigationController right usage

Question

I've implemented UINavigationController in my iphone application as main navigation interface.

When I need to add some new xib to my UINavigationController stack I have to write new method like this (example for ContactsView.xib):

- (void) switchToContactsView
{
   // lazy load
   if (self.contactsViewController == nil)
   {
      ContactsViewController *contactsController = [[ContactsViewController alloc]
                                     initWithNibName:@"ContactsView" bundle:nil];
      self.contactsViewController = contactsController;
      [contactsController release];
   }
   [navigationController pushViewController:contactsViewController animated:YES];  
}

The problem is, I have lots and lots of .xib screens in my application now now and for every new screen I have to copy and paste the same code, just changing the name of method and class names in it.

Is there some more efficient way of doing this? Like maybe create some single method that accepts parameters (xib and uiviewcontroller subclass name), so I can just call it with those parameters to load new xib and switch to it. The problem is, I don't know how to pass class name to a method (eg ContactsViewController class in the example above). Any help?

Answer 1

- (void) switchToAViewController: (NSString *)vCName: (NSString *)nibName
{
   // lazy load
   if (self.toBePushedViewController == nil)
   {
      //Assuming all VCs are subclasses of UIViewController
      UIViewController *tempViewController = [[NSClassFromString(vCName) alloc]
                                     initWithNibName:nibName bundle:nil];
      self.toBePushedViewController = tempViewController;
      [tempViewController release];
   }

[navigationController pushViewController:self.toBePushedViewController animated:YES]; 
}

Also refer to http://stackoverflow.com/questions/2227085/nsclassfromstring-returns-nil

Answer 2

Is there a reason you have many xibs in your project ? Read the apples interface guidelines, Many new-commers to iPhone development misunderstand the rationale behind some of the interface elements. Aside from that, if you need many xibs, but all of them have exactly the same functions consider linking the xibs to the same class file, so one controller having 3 xibs etc. that way you will only need to point to the correct xib instead of copy the whole method.

Just a thought, but please explain the reason behind having so many xibs, what is your application's purpose?