lemonkey/gist:637e855e0ba118a50218

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    Using Swift 2 and Objective-C classes within frameworks, apps and unit tests

Normal Usage:


Swift into Obj-C:

Within framework or app:

Because the auto generated Swift interface header "Objective-C Generated Interface Header" SWIFT_OBJC_INTERFACE_HEADER_NAME for a framework target is part of the framework’s public interface, only Swift declarations marked with the public modifier for classes or structs marked with @objc appear in this header for a framework target.

Framework:

#import <ProductName/ProductModuleName-Swift.h>
This could go in the Framework’s prefix PCH file if used as a local dev pod, otherwise not recommended (reserve PCH for things that don’t change often like UIKit, etc.)
Note: You can still use Swift methods and properties that are marked with the internal modifier from within the ObjC part of your framework, as long they are declared within a Swift class that inherits from an ObjC class.


App:

#import “ProductModuleName-Swift.h”
Shouldn’t go in the app’s prefix PCH file since these Swift classes could change often.


Outside framework:

If only public Swift classes/structs from framework are needed:

#import <ProductName/ProductModuleName-Swift.h>


If both Obj-C and Swift classes/structs from framework are needed:

@import FrameworkName;


Obj-C into Swift:

Within framework:

Framework umbrella header must have a system import for each Obj-C class needed (double quote import won’t work):

#import <ProductName/ClassName.h>
Note that using bridging headers with framework targets is unsupported.


Within app:

"Objective-C Bridging Header" SWIFT_OBJC_BRIDGING_HEADER created when first Swift class was added to the app (or created manually and set in the build settings) must include an import for each Obj-C class that needs to be visible to all Swift classes (in import in Swift class is needed).

#import “Classname.h”


Outside framework:

import FrameworkName


Swift into Swift:

Within framework or app:

Nothing needs to be done as long as Swift class or struct is public.


Outside framework:

import FrameworkName


Obj-C into Obj-C:

Within framework or app:

#import “Classname.h”


Outside framework:

If all Obj-C classes that exist in the Framework’s umbrella header are needed:

@import FrameworkName;


If only certain Obj-C classes in the Framework’s umbrella header are needed:

@import FrameworkName.Classname;
Note: #import “Classname.h” should continue to work depending on the framework headers search path for your build settings. System import #import <FrameworkName/Classname.h> shouldn't be necessary.


Unit Tests:


Swift tests:

Obj-C and Swift classes:

From Framework:

import FrameworkName


From main app:


Main app must enable testability, modules and have product module name set


@testable import MainAppProductModuleName


Obj-C tests:

Swift classes:

From Framework:

@import FrameworkName;


From main app:


Main app must enable modules and have a product module name set


Test target HEADER_SEARCH_PATHS must include path for test host target’s auto generated swift interface header file:


"$(TARGET_TEMP_DIR)/../$(PROJECT_NAME).build/DerivedSources"
http://stackoverflow.com/a/28138792


#import “MainAppProductModuleName-Swift.h”


Note: recommended that test classes that need to test main app Swift classes be written in Swift. Apple doesn’t officially support Obj-C test classes accessing Swift classes from the test host.

http://stackoverflow.com/a/24933328


Obj-C classes:

From Framework:

Same as Swift (@import FrameworkName;)


From main app:

#import “Classname.h”


Resources


https://developer.apple.com/library/ios/documentation/Swift/Conceptual/BuildingCocoaApps/MixandMatch.html
http://natashatherobot.com/swift-2-xcode-7-unit-testing-access/
https://kodmunki.wordpress.com/2015/09/22/ios-9-universal-cocoa-touch-frameworks/