iOS Static vs Dynamic frameworks clarifications

ios frameworks static-libraries static-linking ios-frameworks
csotiriou picture csotiriou · Jan 12, 2015 · Viewed 37.2k times · Source

I have to admit that with the release of iOS 8 I am a bit confused about dynamic and static frameworks in iOS.

I am looking for a way to distribute a library that I created, and I need to support iOS 7 and above. (Note: This will be a proprietary framework. I cannot use cocoa pods, and I also cannot distribute the source). Here is what I already know:

  • iOS 8 introduced "embedded frameworks" for iOS, but, as I understand, they do not work for iOS 7, only for iOS 8 and above.
  • I have the option of distributing my library as a static library (.a file) and also distribute the headers. I know that this is a common way of dealing with the situation, but I would like to find something simpler than that (and also to bundle some resources with it, if possible).
  • I have also found that iOS 7 does not support dynamic .framework libraries (only static) because it doesn't support dynamic linking. But iOS 8 does, as well as static linking.

And here are my questions regarding this information:

  • I saw that I can create a .framework target, and make it static, by changing the Mach-O type to "static library. Would that be enough in order to support iOS 7 without any problems, and also to distribute my library as a .framework bundle? If so, why is "embedded frameworks" in iOS 8 that big of a deal, as many resources on the internet are suggesting? Am I missing something?
  • Is it necessary to codesign the .framework just as I do with any other application I make?
  • What if I need to include other resources (like Core Data or Images) with my .framework file? Will I need to make a separate .bundle file for that?

Answer

Subbu picture Subbu · Jul 2, 2015

Before iOS8, Xcode only allowed the option of creating static libraries for iOS. The common problem with that was we had to ship the binary and headers separately.

Later, some developers came with the idea of creating 'static frameworks'. [the .framework is just a folder with symbolic links to the lib and the headers]. One such example is https://github.com/jverkoey/iOS-Framework

This option will work for iOS 7 or 8 or before that. Because they are just static libraries with the convenience of bundling the headers files along.

As for your questions of the resources, we would need to bundle them in '.bundle'.. For shipping them i am not sure if we can enclose them in the .framework folder.. In the past i used to ship my libs as a static framework and bundle...

However the above option will not work for you if you use Swift. Xcode does not support building static libraries that include swift code.

You must go with Dynamic frameworks if there is swift usage. In theory, Dynamic frameworks work in iOS7.. But, i think iTunes Connect will reject if the app is targeting iOS7 and uses Dynamic frameworks :-).

Hope this helps

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