XIB
As of MacOS 10.3 Apple moved away from the binary encoded nib files, and towards the xml encoded XIB files, for their interface definitions. As of 10.9 (Xcode 5) Apple changed to xib file format totally, that format is not supported by Gorm currently.
Xib file format
The xib file format is actually quite easy to understand, it is the responsability of the object encodeing and decoding, it to insure that it's attributes are read correctly.
Here is a commented example of a XIB file. For easy reading open it in a syntax highliting editor using XML highlighting.
To provide cross platform compatability, review the "XIB fields" section of the gnustep wiki article on the interface you intend to provide a codec for. Also be sure to read the apple article on KVC.
See Also
- Apple on KVC - Encoded objects must be KVC complient
- Apple on KVO -KVO explains how to decode KVC objects.
- XIB File Format Definition as understod by MonoObjc
Compatibility to Cocoa/macOS
As of version 1.2.24 Gorm is able to read xib and nib files from Xcode up to version 4 (to some extend). Gorm can save nib files, but this nib files currently cannot be read by Xcode 3 and above. This means for development of cross platform xibs/nibs you need to use Xcode *below* version 5, meaning a Mac OS X version of 10.8 and below.
Using .nib and .gorm files in parallel
You can use .nib and .gorm files in parallel to develop cross platform applications. GNUstep will load a .gorm file over a .nib file given the same name.