Resource-only NSBundle: is this kosher?

In my iOS app, I'm downloading content from the web into my /Library/Caches directory. I'd like to represent this directory as an NSBundle for better compatibility with some of the external APIs we're using. (That way, we can simply change [[NSBundle mainBundle] pathForResource...] to [myBundle pathForResource...] whenever it appears.)

The following seems to work fine:

NSArray* paths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);
NSString* cachesDirectory = [paths objectAtIndex:0];
NSBundle* bundle = [NSBundle bundleWithPath:cachesDirectory];

Better yet, the bundle reflects any changes I make to the /Library/Caches directory. However, I'm concerned because the caches directory is technically not a bundle per Apple's docs. That is to say:

• It's not a "directory with a standardized hierarchical structure that holds execut开发者_运维百科able code and the resources used by that code", since there's no code.
• It's neither an Application, Framework, nor a Plug-In bundle.
• It's most like an Application bundle, but it doesn't contain the required Info.plist or executable.

I could find no mention anywhere of this sort of dynamically-created, resource-only bundle. Is this okay to do?

The /Library/Caches directory will lack some of the standard files which are required in a bundle, like a Contents/ directory or a Contents/Info.plist file, so it may not behave properly when treated as one. Proceed with caution.

Yes, it's absolutely okay to have a resources only bundle. Some of the verbage that you quote pre-exists iOS. In OS X you can dynamically load executable code, that's specifically excluded in iOS.

Localization is an example of resource only bundles.

Edit:

The Bundle Programming Guide says:

Although document formats can leverage the bundle structure to organize their contents, documents are generally not considered bundles in the purest sense. A document that is implemented as a directory and treated as an opaque type is considered to be a document package, regardless of its internal format. For more information about document packages, see “Document Packages.”

which says:

There are several ways to access the contents of a document package. Because a document package is a directory, you can access the document's contents using any appropriate file-system routines. If you use a bundle structure for your document package, you can also use the NSBundle or CFBundleRef routines. Use of a bundle structure is especially appropriate for documents that store multiple localizations.

also note that Apple has been telegraphing that it is minimizing the use of "path"/NSString APIs in favor of URL APIs, though existing path APIs will no doubt continue for many more major OS releases.