How should I manage dependencies across projects in an Xcode workspace?

Question

I\'m working on an iOS app project, and add the json-framework project to the workspace. The project navigator on the left shows both projects, and the build scheme selector

Answer 1

I've had some success with creating framework-like static libraries, though it's not a perfect solution.

Answer 2

See the Xcode user guide: Xcode Concepts -> Xcode workspace under 'Projects in a Workspace Share a Build Directory'.

All projects in a single workspace share a build directory. Dependencies are discovered automatically and build if needed:

"Xcode examines the files in the build directory to discover implicit dependencies. For example, if one project included in a workspace builds a library that is linked against by another project in the same workspace, Xcode automatically builds the library before building the other project, even if the build configuration does not make this dependency explicit. You can override such implicit dependencies with explicit build settings if necessary. For explicit dependencies, you must create project references."

Answer 3

I was going to ask the same question, thinking that my own solution couldn't be right. But I don't see it mentioned here, and it does seem to work. Clearly XCode 4 is a work in progress. :)

I have a workspace with two projects: a static library and an app which uses the library. The projects are siblings. Each project has its own scheme, and each scheme is set to only build one target. In other words, I added two projects to the workspace and that's it.

To add the static library as a dependency of the app, I just drag the libsomething.a product from the library project (Project Navigator) into the "Link Binary with Libraries" list for the app target. That's it. Now when I build the app the library project is built first and then linked. Interestingly, when I modify the app's scheme to use a different configuration (eg, Release instead of Debug), the library is built using the same configuration.

So it works, and there is clearly some automatic dependency checking going on here. But it feels wrong. Then again, so does the modal scheme editor/manager and lack of a workspace object in the project navigator... I never thought I'd say it, but the Visual Studio UI (bleh) is a lot clearer.

Answer 4

I’ve just set a test project up, pretty much as you describe in version 3, by creating a new workspace and dragging the two Xcode project into it, nested as shown.

You can delete the sibling project if you have it already.

Hitting build on this and it just works, as far as I can see.

I imagine there is internal path-confusion if you have two projects, and I’d be inclined to fiddle with location settings in "View"->"Utilities"->"File Inspector" and see what effect that has.

Another thing to try is to set your paths up in Xcode "Preferences…"->"Source Trees" and refer to them that way, as described here: Easy, Modular Code Sharing Across iPhone Apps: Static Libraries and Cross-Project References

HTH. Andy W.

Answer 5

My bullet-proof solution to do this :

Create "Per Debug-Release / Per Architecture" settings in Build Settings in the Main project (not the lib), to include either ../MyLibProject/build/Debug-iphoneos or ../MyLibProject/build/Release-iphonesimulator or etc..
depending on the configuration (you can create those kind of configuration by clicking on the + next to Debug or Release and choose either "Any iOS Simulator SDK" or "any iOS SDK". You need to do that for both "Header Search Path" (in case your library copy some headers files, which is more than likely) AND for "Library Search Paths". Which means that for each setting, you'll probably end-up with 4 different paths (debug sim , debug ios, release sim, release ios). That would make sure the configuration of both projects match.

Now, to auto-compile the lib, that is to create the dependency, you can use the "Build Phase -> Link to Binary With Libraries -> + -> select the .a file" advice given above.

That's the only way I managed to have something that builds and link correctly for every environment on xcode 4.5

Note : I even added the -lmyLib flag in "other linker flags", but i'm not sure that's really necessary

Answer 6

I managed to get dependencies between projects in a workspace to work as I described here: http://blog.carbonfive.com/2011/04/04/using-open-source-static-libraries-in-xcode-4/.

Unfortunately I can't find a way to get Xcode to discover implicit dependencies or index everything in the build as advertised. I found workaround to both but I'm hoping that less manual configuration will be needed as Xcode 4 matures.