Loading NIBs stored inside a bundle

Posted bylantean

When does it make sense to store your NIBs inside a bundle?. As we’ve discussed before… this becomes handy when you’re distributing a framework which has some custom NIB files.

But wait…. how do you tell a UIViewController to load its nib file from a bundle?. Short answer… we’ll rely on UIViewController’s ‘initWithNibName: bundle:’ constructor.

Before doing that… we need to take care about a small detail, which is, how to load a NSBundle object (to pass on as the ‘bundle’ parameter).

We’ll show you the required code below, encapsulated into a nice helper class:

@interface LABundles
+ (NSBundle*)someResourcesBundle;
@end

@implementation LABundles
NSString* const kSomeResourcesBundleName = @"SomeResources.bundle";

+ (NSBundle*) someResourcesBundle
{
   static NSBundle* someResourcesBundle = nil;
   if ( someResourcesBundle == nil )
   {
           @synchronized(self)
           {
               if ( someResourcesBundle == nil )
               {
                   NSString* bundlePath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:kSomeResourcesBundleName];
                   someResourcesBundle = [[NSBundle bundleWithPath:bundlePath] retain];
               }
           }
   }

    return someResourcesBundle;
}
@end

Finally, in order to alloc an UIViewController, and load its nib from the SomeResources bundle, we need to do the following:

    SomeViewController* someVC = [[SomeViewController alloc] initWithNibName:NSStringFromClass([SomeViewController class])
                                                                      bundle:[LABundles someResourcesBundle]];

That’s it!. SomeViewController should be loading its nib file from the someResources bundle.