How do I flag a folder as being a package?

Question

I used to think that folders needed to have an extension so that they are recognized as packages by the Finder. That extension would be declared in the owning application\'s Inf

Answer 1

Although you should not rely solely upon it, one thing to do is set the file's bundle bit. I've got a category on NSWorkspace to do just that:

- (void)setBundleBit:(BOOL)flag forFile:(NSString *)path
{
    FSRef fileRef;
    OSErr error = FSPathMakeRef((UInt8 *)[path fileSystemRepresentation], &fileRef, NULL);

    // Get the file's current info
    FSCatalogInfo fileInfo;
    if (!error)
    {
        error = FSGetCatalogInfo(&fileRef, kFSCatInfoFinderInfo, &fileInfo, NULL, NULL, NULL);
    }

    if (!error)
    {
        // Adjust the bundle bit
        FolderInfo *finderInfo = (FolderInfo *)fileInfo.finderInfo;
        if (flag) {
            finderInfo->finderFlags |= kHasBundle;
        }
        else {
            finderInfo->finderFlags &= ~kHasBundle;
        }

        // Set the altered flags of the file
        error = FSSetCatalogInfo(&fileRef, kFSCatInfoFinderInfo, &fileInfo);
    }

    if (error) {
        NSLog(@"OSError %i in -[NSWorkspace setBundleBit:forFile:]", error);
    }
}