Exploring App Functions - unsolved unconference

AndroidX AppFunctions

• KSP plugin
• @AppFunction
• A bound Service
• Various other things (schema, serialization annotation)

class NotosAppFunctions {
    @AppFunction
    suspend fun createNote(
        context: AppFunctionContext,
        text: String,
    ): Long = ...
}

class NotosAppFunctions {
    /**
     * Create a note given some text. 
     * Notes must be less than 2000 characters.
     */
    @AppFunction(isDescribedByKDoc = true)
    suspend fun createNote(
        context: AppFunctionContext,
        text: String,
    ): Long = ...
}

And there’s more

• Custom factories to support constructor injection
• Describe functions with a versioned schema
• Complex, Serializable inputs and outputs

<uses-permission android:name="android.permission.EXECUTE_APP_FUNCTIONS"/>

<queries>
    <package android:name="dev.sanson.notos"/>
</queries>

val manager = AppFunctionsManagerCompat.getInstance(context)

val searchSpec = AppFunctionSearchSpec(
    packageNames = setOf("dev.sanson.notos"),
    schemaCategory = "???",
    schemaName = "???",
    minSchemaVersion = 0 // ???
)

val functionPackages: Flow<List<AppFunctionPackageMetadata>> = 
    manager.observeAppFunctions(searchSpec)

val request = ExecuteAppFunctionRequest(
    targetPackageName = "dev.sanson.notos",
    functionIdentifier = "dev.sanson.notos.NotosAppFunctions#createNote",
    functionParameters = ...
)

val manager = AppFunctionsManagerCompat.getInstance(context)

val response = manager.executeAppFunction(request)

val manager = AppFunctionsManagerCompat.getInstance(context)

val response = manager.executeAppFunction(request) // 💥