TravelPostersNative

This is a demonstration of using a shared Skip dual-platform model library in native Swift to power both an iOS and an Android app.

Workflow

Iterate on both the travel-posters-model shared model package and the iOS app by opening the TravelPostersNative.xcworkspace Xcode workspace.

Iterate on the Android app by opening the Android/settings.gradle.kts file in Android Studio.

To donate the latest travel-posters-model shared model code to the Android app's debug target and then build the app:

$ skip export --project travel-posters-model -d Android/lib/debug/ --debug
$ gradle -p Android assembleDebug

Similarly, for the release build, you would run:

$ skip export --project travel-posters-model -d Android/lib/release/ --release
$ gradle -p Android assembleRelease

There are many ways to automate this process, from simple scripting to git submodules to publishing the Android travel-posters-model output to a local Maven repository. Use whatever system fits your team's workflow best.

For example, to re-build and re-launch the app after making changes to the Swift code, you might run:

skip export --project travel-posters-model -d Android/lib/debug/ --debug
gradle -p Android installDebug
adb shell am start -a android.intent.action.MAIN -c android.intent.category.LAUNCHER -n tools.skip.travelposters/tools.skip.travelposters.MainActivity

Building & Running

Use Xcode to build and run the iOS app and the shared travel-posters-model package.

Use Android Studio to build and run the Android app. Before building the Android app the first time, you must follow the instructions above to donate the native model build. Then use “Sync Project with Gradle Files” in Android Studio to sync the donated libraries. Do this every time you update the library versions.

Deployment Notes

Note the following declaration in Android/app/build.gradle.kts:

android {
    packaging {
        jniLibs {
            // doNotStrip is needed to prevent errors like: java.lang.UnsatisfiedLinkError: dlopen failed: empty/missing DT_HASH/DT_GNU_HASH in "/data/app/…/base.apk!/lib/arm64-v8a/libdispatch.so" (new hash type from the future?) (see: https://github.com/finagolfin/swift-android-sdk/issues/67)
            keepDebugSymbols.add("**/*.so")
        }
    }
}

This is needed to prevent a known issue with some compiled Swift libraries.