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Building a Swift framework with references to Objective-C code

Posted by: admin November 30, 2017 Leave a comment

Questions:

I’m working on an iOS project written in Swift, and I would like to take some classes out of the regular “app” project, and bundle it into a reusable Swift framework instead (and maybe make it publicly available on Github and via Cocoapods).

I’m running into issues because frameworks seemingly can’t have Objective-C bridging headers, but in order to compile my framework code, I need to reference several Objective-C classes (in this case: the Google Maps iOS SDK).

I’ve also added GoogleMaps.framework as a linked library in my framework project, but then, how can I “import” it from Swift code?

Is this even possible with the current tools and Swift version, and how should I proceed?

Thanks.

Answers:

It wasn’t that complicated, actually… I was just doing some things wrong.

First, bridging headers are not required in that setting: the Google Maps iOS SDK is provided as a regular .framework file, so the development language has no impact on how it can be imported in Swift. Apple clearly mentions it in the documentation: https://developer.apple.com/library/ios/documentation/Swift/Conceptual/BuildingCocoaApps/MixandMatch.html, “Importing external frameworks”.

It’s as easy as adding the framework to the “Link binary with libraries” section of the project settings. Do not forget to also add depending libraries and frameworks (in GoogleMaps.framework’s case, there are quite a few).

Then, in Swift code, the framework classes should be available simply by doing:

import GoogleMaps

No bridging header, no dealing with “non-modular header etc.” errors.