XCode - Editing xcodeproj bundle (specifically project.pbxproj)

Question

I'm working in XCode and I've also written an external editor tool that generates resources for use in the project. In the best case scenario, the tool would edit the project.pbxproj file so that it includes the generated resources in the project. I've read through the file in an attempt to understand it, and it's mostly discernible but there is still one major question I have.

If I wanted to generate a new Group from outside XCode (or a new anything, for that matter), how do I know what ID code to use? For example: 19C28FACFE9D520D11CA2CBB is one of them from my project. How am I supposed to know what to use if I make my own? Do they just need to be unique? Would it be legal to just make one up: 000000000000000000000001 and 000000000000000000000002 and 000000000000000000000003 etc. ?

Any help on this would be wonderful. Thanks.

Answer 1

Yes, you can make your own. The best way would be to use a hash function such as MD5 or SHA1 to generate it then you can truncate it at the desired length. I would hash the name of the file/group along with a time stamp appended this way you get a more unique result.