AnswerMe

AnswerMe SDK Sample

This sample demonstrates how to create an SDK out of Java code which can be easily used from Objective-C/Swift. Unlike the MyJavaFramework sample this sample doesn't rely on JNI to the same extent. Instead, the SDK implements wrapper classes in Java which are exposed as Objective-C classes using the RoboVM Objective-C to Java bridge.

This sample consists of a number of modules and sub-projects:

• The core/ module contains the platform independent code which we want to expose in the SDK.
• The app/ module contains an ordinary RoboVM iOS app which exercises the code in core. This app can be used to debug the core code.
• The sdk/ module contains the Objective-C wrapper classes for the various classes in core. The classes are still implemented in Java but will be made available to the Objective-C runtime when loaded.
• The Xcode project in sdk/AnswerMeObjC/ demonstrates how to use the SDK from Objective-C.

The first step to run any code in this sample is to install the root POM and compile and install the core module:

mvn -N install
mvn -f core/pom.xml install

To run the sample app in app in the iOS simulator:

mvn -f app/pom.xml compile robovm:iphone-sim

To create the SDK iOS framework:

mvn -f sdk/pom.xml -Drobovm.enableBitcode=true compile robovm:install

This creates the SDK framework in sdk/target/robovm/AnswerMeSDK.framework.

The Objective-C app in sdk/AnswerMeObjC/ can then be launched.

NOTE: The Xcode project depends on Carthage. Carthage must be installed in /usr/local/bin/carthage in order for the Objective-C app to work.

Details

The entry point to the SDK is defined in the Objective-C source file sdk/src/main/native/init.m. The [AMAnswerMeSDK instance] method will initialize RoboVM using standard JNI and then calls the org.robovm.answerme.sdk.AMAnswerMeSDKImpl.initialize() Java method via JNI. initialize() registers the Objective-C classes implemented in Java with the Objective-C runtime dynamically. Once this has been done the Objective-C code in the app can call methods and properties on these classes just like they had been implemented in Objective-C.

In order to link against the dynamic Java framework the AnswerMeSDK.framework library has been added to the Link Binary With Libraries build phase on the AnswerMeObjC target.

Also, a Run Script phase has been added to the build phases of the AnswerMeObjC target. This Run Script phase runs /usr/local/bin/carthage copy-frameworks with $(SRCROOT)/../target/robovm/AnswerMeSDK.framework as input file. This is necessary to have the framework copied properly and unnessary architectures removed from the dynamic library file when launched on the simulator or on device. This script also takes care of signing the framework.