ios - Check for framework's existence at compile time?

Question

I'm working on an open-source project that can optionally use a closed-source framework. If the closed-source framework is included in the project, there will be additional functionality. But if the framework isn't included in the project, the project should still compile properly.

How do I check at compile-time if the framework is included in the project?

Basically, I want to do something like this:

#ifdef _MY_FRAMEWORK_EXISTS
#import <MyFramework/MyFramework.h>
#endif

I've seen older questions from 2 years ago like this one, but no answer has surfaced so I might be missing something new now.

I DON'T want to check at run-time via NSClassFromString(), because this will fail at compile time when I try to import MyFramework and it doesn't exist.

Answer 1

You can check for the presence of a header file using the __has_include language extension. http://clang.llvm.org/docs/LanguageExtensions.html#include-file-checking-macros

However, that only tells you if the header file is installed. It can't tell you if "Link Binary With Libraries" has linked to its framework.