Using subproject's xcdatamodelId in main project

Question

I have in XCode a main project that relies on a subproject to work. The subproject is basically a library that also define a database model, and the way to interact with it.

To use the subproject in the main project, I just dropped the subproject xcodeproj file in the main project, did some setup (like specifying header search path), and that's it.

I'm using core data, but if I try to use the .xcdatamodelId files directly, by creating managed object context, it fails : looks like the main project can't find the subproject ressources (except .h and .m files).

The only solution I found so far is to copy the .xcdatamodelId file from the subproject in the main project, and it does the trick. But it's not satisfactory, as I have to maintain two files if my model evolves.

Answer 1

I was struggling with this issue for a while and I want to answer it here as I believe it is important.

In order to add model files from a sub-project into the parent project you simply locate the model files you want to add in Finder. You can then drag them into your project into any folder you see fit. When Xcode displays the "Choose options for adding these files" prompt, deselect the "Copy items into destination group's folder" item and you can select either "Create Groups..." or "Create folder references...". After this process you should see the model files under the compile sources phase in Build Settings.

It is important to note that dragging the model files (in Xcode) from the sub-project into either "Compile Sources" or the parent project will not work to my knowledge so rather do it in Finder.