Cannot import / add native Kotlin Module in React Native

Issue

Problem

I am trying to create my own native module, but React Native can't load it. I always get this error when trying to start the app with npx react-native start:

/home/somedude/Development/my-app/android/app/src/main/java/com/coolapp/MainApplication.java:28: error: cannot find symbol packages.add(new GLBPackage()); ^ symbol: class GLBPackage

What I did

I followed the documentation to a point to create that module. This is from my MainApplication.java:

    @Override
    protected List<ReactPackage> getPackages() {
      @SuppressWarnings("UnnecessaryLocalVariable")
      List<ReactPackage> packages = new PackageList(this).getPackages();
      packages.add(new ReactViroPackage(ReactViroPackage.ViroPlatform.valueOf("AR")));
      packages.add(new GLBPackage());

      return packages;
    }

I also created an GLBPackage.kt:

class GLBPackage : ReactPackage {

    override fun createViewManagers(
        reactContext: ReactApplicationContext
    ): MutableList<ViewManager<View, ReactShadowNode<*>>> = mutableListOf()

    override fun createNativeModules(
        reactContext: ReactApplicationContext
    ): MutableList<NativeModule> = listOf(GLBModule(reactContext)).toMutableList()
}

and a GLBModule.kt:

class GLBModule(reactContext: ReactApplicationContext) : ReactContextBaseJavaModule(reactContext) {
    override fun getName(): String {
        return "GLBModule"
    }

    @ReactMethod
    fun loadModel(path: String) {
        Log.d("GLBModule", "Loading $path")
    }
}

Why do I get this error? Android Studio also says everything is ok.

Solution

I had a similar error when trying to load the CalendarModule provided in the ReactNative docs using Kotlin.

What worked for me: I added the kotlin-android plugin the app level build.gradle file like so:

apply plugin: 'kotlin-android'

And, the androidx.core and kotlin implementations under the implementation section like so:

implementation 'androidx.core:core-ktx:$' implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"

Similarly, I also added the following configs in the project level build.gradle file in the dependencies section, like so:

classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"

Source: React Native Project with Kotlin and Swift

Answered By - Innocent Oyebode