Can't Touch Nibs

I heard something recently on the grapevine that I haven't yet seen in the blogosphere, so I thought I should mention it. If there's any demand, I'll dig deeper into the code and post further details.

- Open up Interface Builder, create and save a new blank nib file(Cocoa/Application).
- Locate the new nib in Finder, and 'Show Package Contents'.
- Delete 'classes.nib' and 'info.nib', but leave 'keyedobjects.nib'.
- Attempt to reopen the modified nib package in IB.
- Marvel at IB's reluctance to open the file for editing.

Ok, so IB won't open it, so what?

It turns out that IB's 'Open' command and [NSBundle loadNibNamed:owner:] have entirely different requirements regarding the contents of the nib package we're attempting to load/open.

The reason this came to light was that someone was trying to have a look at XCode 2.4.x nibs, which lack the 2 files we deleted above. I'm not sure when Apple started deleting those 2 files, but on my box(XCode 2.2) I have all 3 internal files in 'PBX.nib' and 'PBXActiveOperationsPanel.nib'. But obviously, since XCode 2.4.x launches with no errors, those 2 deleted files aren't needed at runtime.

So, at first glance, the moral of the story is- you can keep your users from opening your nibs in IB(thus keeping those damned GUI hackers at bay) by simply deleting the aforementioned files from your nibs, possibly with a custom build phase.

But just for fun, we glanced twice.

- Repeat the 'create and save a blank nib file' steps, but this time, don't delete anything.
- Copy 'classes.nib' and 'info.nib' from the newly created nib package into the unopenable nib package.
- Marvel at IB's willingness to open the previously unopenable file for editing.

I am sure that there is some information lost in the translation, but this seems to be a good start. As always, any comments/questions/suggestions are welcome.